Alkaline Diet

Diet Reference Archive: a popular diet built on a claim about the body’s acid and base balance

Alkaline Diet

A diet that sorts foods into acid-forming and alkaline-forming groups and asks followers to eat mostly the alkaline-forming ones, chiefly vegetables and fruit. It is promoted on the claim that food can change the body’s pH to prevent or treat disease, but diet changes the pH of urine far more than the pH of blood, which the body holds in a narrow range.

Family: Fad, extreme, and debunked dietsPromoted by: no single owner; popular book authors, among them Robert O. Young of the pH Miracle books, and sellers of alkaline water and water ionizersFirst appeared: built on the acid-ash idea, which is more than 100 years old; the popular diet spread through books, websites and productsGRADE: Not rated for whether the change in resting blood pH after 4-day planned alkalizing compared with acidizing study diets, in healthy young adults, is below a clinically important threshold; this page’s own decision

ON THIS PAGE

1. In brief
2. Overview
3. In practice
4. For the coach
5. The evidence (opens on request)
6. Mechanisms (opens on request)
7. Risks, contraindications and myths (opens on request)
8. Key terms
9. Review questions
10. References
11. Evidence rating and review record

The summary and sections 1 to 3 are the short version and are open when the page loads. Sections 4 to 6 hold the research detail, the biology, and the cautions. Each of those opens when you select its heading, and you can read the page without opening them. This page keeps 4 things apart that the diet’s marketing runs together: the pH of the blood, the pH of urine, scores that estimate a diet’s acid load, and the health outcomes claimed. Back to the Diet Reference Archive index.

In brief

What is it? A diet that labels foods as acid-forming or alkaline-forming and asks followers to eat mostly the alkaline-forming ones: vegetables, fruit, and some legumes, nuts and seeds, with meat, cheese, many grains and processed foods limited or removed. No one owns the name, and the food lists differ from one source to the next; British cancer dietitians note that there is “no consensus on grouping foods as acid or alkaline with many misclassified” (British Dietetic Association Oncology Specialist Group, 2021).

Does it work? The diet’s central claim is that food makes the blood more acidic or more alkaline. In healthy people the lungs and kidneys hold blood pH in a narrow range, about 7.35 to 7.45 (Frassetto et al., 2018). In 3 small crossover experiments in healthy young adults, 4-day periods of planned alkalizing study diets raised urine pH by about 0.9 to 1.5 units compared with acidizing diets. The reported between-diet blood-pH changes were small, about 0.01 to 0.014 units. Sample type, measurement conditions and analyses differed. These results do not establish that the popular alkaline diet prevents or treats disease (Buclin et al., 2001; Limmer et al., 2018, 2020).

Studies that score people’s usual diets by acid load find modest links with type 2 diabetes and cancer, and they cannot show that acid load causes them (Abbastabar et al., 2025). A systematic review found no trial of the diet or of alkaline water for preventing or treating cancer (Fenton & Huang, 2016), and a review of the bone research concluded that there is “no evidence that an alkaline diet is protective of bone health” (Fenton et al., 2011).

Is it safe? For most adults, eating more vegetables and fruit matches heart-health guidance (Lichtenstein et al., 2026). The documented harms fall on particular groups. Three infants fed homemade formulas based on “alkaline diet” recipes developed dangerously low blood calcium and rickets (Calello et al., 2021). A child with kidney disease who took a calcium-based medicine developed high blood calcium and worse kidney injury from drinking alkaline water (Kermond et al., 2022). People with kidney disease may need to limit many of the diet’s high-potassium foods (National Kidney Foundation, 2023). For cancer, British cancer dietitians state: “There is no scientific literature establishing the benefit of an alkaline diet for curing cancer” (British Dietetic Association Oncology Specialist Group, 2021).

Who should not do it without talking to a doctor or dietitian first? Anyone with kidney disease; anyone taking medicine for blood pressure, heart failure, diabetes or blood thinning; anyone with cancer; anyone pregnant or breastfeeding; parents planning a child’s diet, and no infant should be fed a homemade formula (U.S. Food and Drug Administration, 2021a); and anyone with a history of disordered eating.

Related pages: DASH Diet, Mediterranean Diet, Whole-Food Plant-Based Diet, Vegan Diet, Detoxes and Cleanses. Full list on the archive index.

1. Overview

What you eat

The diet is built on food lists rather than on amounts. Foods are sorted by what they are said to leave behind once the body has used them, an acid or an alkaline (base) “residue,” rather than by how sour they taste. Vegetables and fruit sit at the alkaline-forming end of nearly every list: leafy greens, broccoli, cucumber, celery, avocado, berries, apples, bananas and citrus. Many lists add beans, lentils, tofu, almonds and seeds such as flax and chia, and plant oils such as olive and avocado oil.

Some versions set a proportion instead of an absolute rule, for example eating most of the plate from alkaline-forming foods and a small share from acid-forming ones. A lemon counts as alkaline-forming even though lemon juice is acidic, because the label describes the food after it has been metabolized, not the food in the glass. Followers often add alkaline water, and some test the pH of their urine or saliva with paper strips to see whether the diet is “working.”

What you avoid or limit

Meat and poultry are limited or removed in most versions, and hard cheese, processed meats, sweets, sugar-sweetened drinks and processed foods generally are discouraged. Eggs, fish, other dairy foods and grains are treated differently from one list to the next: some lists limit them, some allow them in moderation, and the strictest versions remove whole food groups, including grains and all animal protein. Whether a given food counts as “acid” or “alkaline” depends on which list a person uses, and the lists disagree. The limits are presented as firm rules by some promoters and as proportions by others.

Where it came from

The idea behind the diet, usually called the acid-ash hypothesis, is more than 100 years old. It holds that the mineral and protein components of foods leave an acid, alkaline or neutral residue, and that a diet heavy in acid-forming foods has to be neutralized by the body (Fenton & Huang, 2016). By 1985, a review in the dietetics literature concluded that diet does influence the pH of urine, but that the food-table calculations then used to rank foods as acid or alkaline ash were “time consuming, imprecise, and do not permit quantitative prediction of urine pH” (Dwyer et al., 1985).

Researchers later developed a calculation called the potential renal acid load, which estimates the acid a food leaves for the kidneys to excrete from its protein, phosphorus, potassium, magnesium and calcium. In the 1995 paper that published values for common foods, certain hard cheeses had the highest values, and fruits, fruit juices and vegetables had negative values, meaning they leave base rather than acid; summed over a day’s eating, the estimate predicted the acidity of urine (Remer & Manz, 1995). That research tool is a different thing from the popular diet, which uses similar food lists to make claims about blood and disease.

The popular diet spread through books, websites and products. Among the best known books are Robert O. Young’s pH Miracle series. In 2016, a San Diego County jury convicted Young of 2 counts of practicing medicine without a license; the prosecutor said he had given at least 6 terminally ill cancer patients intravenous sodium bicarbonate at $500 a treatment (City News Service, 2016). In 2017 he pleaded guilty to practicing medicine without a license and admitted that he had no post-high school degree from an accredited school and was not a medical doctor or trained scientist (Stone, 2017). His case is one promoter’s story, not the whole diet; many people who follow alkaline food lists have never heard of him.

What it claims to do

The authors of a 2016 systematic review summarized the claims as they found them in the popular press: that modern diets make the body acidic, that this acidity causes diseases including cancer, osteoporosis and cardiovascular disease, and that choosing more alkaline-forming foods prevents them; the diet is also promoted for diabetes and high blood pressure. The same authors note that the public is encouraged to test the acidity of urine or saliva as a measure of the body’s acidity and to change what they eat accordingly, and that the marketing sells supplements and water-alkalizing machines as well as a diet (Fenton & Huang, 2016).

Alkaline water sellers make related claims; a British advertising regulator’s 2013 ruling quotes one seller’s website saying that alkalized water is “beneficial to help to neutralize excess tissue acidity” (Advertising Standards Authority, 2013). Whether the evidence supports any of these claims is the subject of section 4.

What it gets right

The foods the diet puts first are the foods most heart-health guidance asks people to eat more of. The American Heart Association’s 2026 dietary guidance lists “eating plenty of vegetables and fruits and choosing a wide variety” among the features of a heart-healthy eating pattern, along with choosing minimally processed foods instead of ultraprocessed foods and minimizing added sugars (Lichtenstein et al., 2026). A coach can honor a client’s wish to eat more vegetables and fruit without accepting the reason the diet gives for it.

The credit belongs to the food pattern, not to the alkaline claim. The authors of the main systematic review on cancer noted that the diet emphasizes fruits, vegetables, roots and tubers, and legumes, and that any protective effect of these foods would come “not through their acidity/alkaline-promoting qualities but rather due to nutrient and non-nutritive compounds” (Fenton & Huang, 2016). The same Heart Association guidance also lists choosing foods made mostly with whole grains and choosing healthy sources of protein (Lichtenstein et al., 2026), which the stricter alkaline lists restrict. Patterns built on more vegetables and fruit, with evidence of their own, are described on the DASH Diet, Mediterranean Diet and Whole-Food Plant-Based Diet pages; their evidence is theirs, not this diet’s.

How clients describe it, and what it gets confused with

A client may say they are “alkalizing,” that their body is “too acidic,” that acidic foods cause inflammation, that they are “on the pH diet,” or that they drink alkaline water or check their urine pH. Each of these points to this page. A client who is cutting meat and dairy may be following an alkaline list, a vegan diet or a plant-based diet for quite different reasons, and the Vegan Diet and Whole-Food Plant-Based Diet pages carry those patterns and their evidence.

The diet is often confused with several other topics. “Acid” in Acid Reflux Diet refers to stomach acid moving into the esophagus, not to the pH of the blood. Juice programs sold to “rebalance” the body are covered on the Detoxes and Cleanses page. Kidney care teams do use diet, and sometimes alkali tablets, to manage acid in people with chronic kidney disease; that clinical use belongs to the broader topic Renal Diet and to the kidney team, not to the popular diet (section 4). Raw Food Diet and Clean Eating are separate topics that can overlap with alkaline food lists.

2. In practice

A typical day of eating

A day built from common alkaline food lists might start with a smoothie of spinach, frozen berries, a banana and chia seeds, or oatmeal topped with fruit in a version that allows some grains. Lunch could be a large salad of leafy greens, cucumber, tomato, chickpeas and avocado with olive oil and lemon. A snack might be an apple and a small handful of almonds. Dinner could be a tofu and vegetable stir-fry with broccoli, peppers and bok choy over quinoa, or a lentil and vegetable soup. Water, often bottled alkaline water for followers who buy it, is the usual drink.

The same day under a strict version would drop the oatmeal and any grain and might drop the tofu or beans as well, which leaves very little protein. Under a looser version that sets a proportion rather than a rule, the day might include a piece of fish or an egg. The plate looks much like a plant-forward eating pattern; what differs is the reason given for it and how strictly the lists are applied.

Cost, products, and who profits

The searches for this page did not identify a study that measured what the alkaline diet costs compared with a usual diet. Its foods are ordinary groceries, so the cost depends mostly on how much fresh produce a person buys and where. The diet itself requires no membership or special product. The money is in what is sold around it: books, bottled alkaline water, water-ionizing machines, test strips and supplements. The authors of the cancer review describe the marketing as selling “related supplements and water alkaliniser machines through almost every media medium, including websites, books and videos,” and report that in their experience patients with cancer are approached by salespeople promoting water alkalizers as a cancer treatment (Fenton & Huang, 2016).

Bottled alkaline water is a large retail category. Essentia’s website, checked on November 8, 2026, describes its product as water that is “99.9% pure with a 9.5pH or higher, electrolytes and a clean smooth taste,” and its sign-up form refers to Nestlé USA’s terms and privacy notice (Essentia Water, n.d.). Those are the company’s claims. A 2026 narrative review reports an analysis in which 5 of 6 alkaline water brands had an average pH lower than their labels stated (Alebrahim et al., 2026).

Water-ionizing machines are a second market. Enagic’s U.S. website, checked on November 8, 2026, describes its Kangen machines as turning tap water into “hydrogen-rich Kangen Water” (Enagic USA, n.d.-a), and its Leveluk K8 product page lists, among five water types, a drinking setting of pH 8.5 to 9.5 described as “Hydrogen-rich water for daily drinking and cooking” (Enagic USA, n.d.-b). Its how-to-buy page states that “All product purchases must be made through an Independent Distributor or at an Enagic branch office” and invites visitors to “build your own business” (Enagic USA, n.d.-c), and its business opportunity page describes becoming a distributor as “operating an independent business” (Enagic USA, n.d.-d). The product page did not show a price, so this page gives none. A seller who earns income from distributing the machines has a financial interest in the health claims a client may have heard.

Regulators have acted on alkaline water claims and products. In 2013, the United Kingdom’s Advertising Standards Authority ruled against a seller’s website for alkaline water filters, concluding: “In the absence of robust evidence to support the claims that alkaline water could neutralise excess tissue acidity and neutralise damaging free radicals, we concluded the claims were misleading” (Advertising Standards Authority, 2013). On December 9, 2021, FTC staff sent Enagic USA a cease-and-desist demand concerning claims by its business opportunity participants or representatives that Kangen Water could prevent or treat COVID-19. The letter said those disease claims lacked competent and reliable scientific support and demanded that they stop. This was an agency warning letter, not a clinical trial or a finding that every alkaline-water product causes harm (Federal Trade Commission, 2021).

One U.S. regulatory action concerned the safety of an alkaline water product. In 2021 the U.S. Food and Drug Administration investigated acute non-viral hepatitis associated with “Real Water” brand alkaline water and told consumers, restaurants, distributors and retailers not to “drink, cook with, sell, or serve” it. The agency’s case count was 21 probable and 4 suspect illnesses, with 23 hospitalizations and 1 death; the company agreed under a consent decree to cease operations until it could comply with federal requirements, and laboratory analyses “did not identify the contaminant that could have led to the illnesses” (U.S. Food and Drug Administration, 2021b). That was a problem with one company’s product, not evidence that alkaline water as such causes liver disease.

For someone with limited money, time or store access, nothing in the research reviewed for this page shows that bottled alkaline water, an ionizing machine or pH test strips add a health benefit to the vegetables, fruit and legumes the diet emphasizes. Canned and frozen vegetables, dried beans and seasonal fruit carry the same kinds of foods at lower cost.

Environmental footprint

The searches for this page did not identify a study that measured or modeled the environmental footprint of the alkaline diet. Its footprint depends mostly on which foods a person chooses within it. Across modeling studies of more sustainable diets, the reductions in greenhouse gas emissions, land use and water use generally tracked how much animal food was cut (Aleksandrowicz et al., 2016). Bottled alkaline water adds its own load: a 2026 review notes that the industry “has also been criticized for extensive plastic bottle use, energy intensive electrolysis, and the carbon footprint associated with global distribution” (Alebrahim et al., 2026).

Cultural fit

The diet fits most easily with cuisines already built on vegetables, legumes, fruit and plant oils. It conflicts with food traditions built around dairy foods, meat, fish or a grain staple such as rice, bread, tortillas or pasta, because the stricter lists label those staples acid-forming. A family meal in many cultures would need its center changed to fit a strict version, while the looser versions leave room for traditional dishes in smaller amounts. This is this page’s reading of the food lists; the searches did not identify a study of how the diet fits particular food cultures.

What makes people stop

The searches for this page did not identify a study of how long people stay on the alkaline diet or why they leave it. The points here are observations from the sources opened, not adherence data. The authors of one trial of a short alkalizing diet note that a calorie shortfall has been reported on alkalizing diets, and that the high needs of sprint athletes for energy, protein and carbohydrate “may make it difficult to realize an alkalizing diet” (Limmer et al., 2018). The strict versions remove whole food groups, and keeping track of which foods are on which list takes planning, especially when eating out or with family.

What happens when you stop

The searches for this page did not identify a study that followed people after they stopped an alkaline diet. What the short trials do show is how quickly the urine responds: in crossover trials, participants changed from an alkalizing to an acidizing diet, or the reverse, within a week, and urine pH tracked whichever diet they were on (Limmer et al., 2018, 2020). Any change in urine pH is expected to follow the food, not to persist after the diet ends. Changes that come from eating more vegetables and fruit would be expected to fade if those foods are dropped, but the searches for this page did not identify a study that measured that.

Common variations

The named and unnamed versions differ mostly in how strict they are and in what is sold with them. Some versions center on alkaline water or on supplements rather than on food. In research, “low-PRAL” or “alkalizing” diets are diets planned with the potential renal acid load calculation to lower a diet’s acid load for a few days or weeks; they are study diets, not the popular diet (Hietavala et al., 2018; Limmer et al., 2018).

The clinical use is different again. In kidney disease the kidneys may not remove enough acid, which is one cause of metabolic acidosis (MedlinePlus, 2025), and kidney researchers have tested fruit and vegetables as a way to lower the diet’s acid load in that setting (Goraya et al., 2013). That is treatment planned by the kidney team, described in section 4 under kidney care, and it is not the popular alkaline diet.

3. For the coach

SCOPE OF PRACTICE

A health and wellness coach does not prescribe, adjust, endorse, or discourage a diet, and does not diagnose or treat. The coach helps the client understand what they have chosen, notice how it is going, and decide what to do next. A coach does not read or interpret a client’s urine or saliva pH strips, blood tests or kidney results, and never suggests this diet, alkaline water or any product to prevent or treat cancer, kidney disease, bone loss or any other condition.

The documented risks of this diet fall on particular groups, and for each the coach makes sure the client has the right professional involved. A client with chronic kidney disease takes any change in eating to the kidney care team, because needs depend on the stage of disease, laboratory results and dialysis, and many of the diet’s foods are high in potassium. A client taking blood pressure or heart medicine that raises potassium, insulin or a sulfonylurea, or warfarin keeps the prescriber informed before a substantial change in eating. A client with cancer keeps the oncology team in charge of treatment.

A client who is pregnant or breastfeeding, a parent planning a child’s diet, and anyone feeding an infant involve the clinician and a registered dietitian, and an infant is never fed a homemade formula. A client with a history of disordered eating involves the existing care team or goes through the coach’s own referral process.

Who does what

The physician

Decides whether the change in eating is medically appropriate for this person, given their conditions and medicines. Orders and reads the tests that matter when there is a reason to: kidney function, potassium, bicarbonate and other blood chemistry, and calcium and vitamin D where intake is low. Adjusts blood pressure, heart, diabetes or blood-thinning medicine if eating changes. Diagnoses and treats metabolic acidosis when it occurs, which is a medical condition with causes such as kidney disease or uncontrolled diabetes, and is the right person to hear about any symptom.

The registered dietitian

Plans an individual eating pattern that keeps the vegetables and fruit while meeting needs for protein, calcium, vitamin D, iodine and other nutrients the stricter lists make harder to get. Designs kidney diets with the kidney care team, including potassium and protein limits where they apply. Plans infant and child feeding, pregnancy nutrition, and nutrition during cancer treatment, and adapts the pattern to athletic training.

The health and wellness coach

Helps the client see what they hope the diet will do and where the idea came from. With the client’s permission, shares general information from recognized authorities, such as heart-health guidance on vegetables and fruit, and explores how the client wants to use it. Helps the client build the habits they choose, notice how the plan fits their life, and keep their own care team in the loop. Holds the referral line when a medicine, a diagnosis, a symptom or a pregnancy puts the question in a clinician’s hands.

What a client bringing this diet needs

A client who brings up the alkaline diet is often looking for a sense of control: more energy, fewer aches, protection from a disease that runs in the family, or a response to a frightening diagnosis. Some arrive having tested their urine and worried about the color on the strip. Others have bought alkaline water or a machine and want to know whether it was worth it. Underneath, many want to eat more vegetables and fruit and feel they need a strong reason to do it.

What the coaching conversation offers that a search engine cannot is room to separate the goal from the explanation. A client can keep the vegetables, the cooking and the sense of taking care of themselves without having to believe that food changes their blood. The coach does not argue with the client’s beliefs or evaluate their products. With permission, the coach can share what health agencies and professional bodies say and explore what the client makes of it; the decision stays with the client, inside the referral boundaries above. Where weight comes up, the coach does not take on a weight target as the goal of the work; this archive treats weight only as something studies measured.

What to ask

• “What drew you to the alkaline diet, and what are you hoping it will do for you?”
• “What have you noticed since you started eating this way, in your energy, your meals, or your daily routine?”
• “Which parts of it feel like they fit your life, and which parts feel hard to keep up?”
• “Who else is involved in your health right now, such as a doctor, a dietitian or a kidney or cancer team, and how much do they know about this change?”
• “If the vegetables and fruit are the part you want to keep, what would make that easier?”

Referral red flags

Some situations call for a referral or for the client’s own care team rather than a coaching conversation. A client with chronic kidney disease, a kidney transplant or a history of high potassium who is changing what they eat needs the kidney care team; so does anyone with kidney disease who drinks alkaline water while taking a calcium-based phosphate binder, the combination behind the case described in section 4 (Kermond et al., 2022). A client taking blood pressure or heart medicine that raises potassium, insulin or a sulfonylurea, or warfarin who plans a substantial change keeps the prescriber informed first.

A client taking insulin or a sulfonylurea who reports symptoms of a possible low blood sugar episode follows their own treatment plan immediately. Severe symptoms or an episode they cannot manage need emergency help. After the episode is addressed, the client tells the prescriber; this does not wait for a coaching discussion. A client who mentions an infant on homemade formula, or a child whose diet is being restricted, needs the child’s clinician promptly; the federal advice is not to make or feed homemade infant formula (U.S. Food and Drug Administration, 2021a).

A client with cancer who says they are using the diet or alkaline water to treat it, or who is thinking of delaying or stopping treatment, needs the oncology team; the coach does not weigh the diet against the treatment. Physical symptoms such as muscle weakness, an irregular heartbeat, confusion, unusual tiredness or swelling need the client’s care plan or a clinician, and the coach does not guess at the cause. Weight a client loses without meaning to is a reason to involve a clinician. Eating behaviors that come with distress, that narrow what the person eats, or that interfere with daily life go through the coach’s own referral process, or to the client’s clinician under an existing care plan.

Special populations

Pregnancy and breastfeeding

The searches for this page did not identify a trial of the alkaline diet in pregnancy or breastfeeding. Strict versions restrict dairy foods and some protein foods, which makes calcium, vitamin D and protein harder to get. Changes in eating during pregnancy and breastfeeding are planned with the obstetric team and a registered dietitian.

Children and adolescents

The searches for this page did not identify a trial of the alkaline diet in children. The documented harm is in infants: 3 infants fed homemade formulas their parents described as the alkaline diet, made from ingredients such as coconut water, hemp seeds, dates and sea moss, developed severe low blood calcium and rickets; one had repeated cardiac arrests and brain injury, and another had growth and developmental delays and iodine deficiency (Calello et al., 2021). The U.S. Food and Drug Administration advises parents and caregivers “to not make or feed homemade infant formula to infants” (U.S. Food and Drug Administration, 2021a). A child’s or teenager’s diet is planned with their clinician and a registered dietitian.

Older adults

The searches for this page did not identify a trial of the alkaline diet as a whole in older adults. A 16-week trial in adults aged 65 to 85 did not detect a clear between-group difference in bone-turnover markers when participants ate 5 or more portions of fruit and vegetables a day (Neville et al., 2014). Older adults who limit dairy foods may find calcium and vitamin D harder to get, and their clinician and a dietitian belong in the plan if they adopt a strict version.

Athletes and people with high activity

Short alkalizing diets have been tested in small groups of recreationally active young adults. One crossover trial in which 11 people were analyzed found a 400-meter run about 1.5 seconds faster after 4 days of an alkalizing diet than after an acidizing one (Limmer et al., 2018); a second, of 15 people, did not find a difference in a 60-second tethered sprint (Limmer et al., 2020). Section 4 describes both. The authors of the first trial note that high needs for energy, protein and carbohydrate can make an alkalizing diet hard to follow (Limmer et al., 2018); a sports dietitian can plan around that.

People taking medication for diabetes, blood pressure, or blood thinning

ACE inhibitors and potassium-sparing diuretics “decrease the amount of potassium lost in the urine and can make potassium levels too high, especially in people who have kidney problems,” while loop and thiazide diuretics increase the potassium lost in urine (Office of Dietary Supplements, 2021). People taking warfarin are advised to “eat consistent amounts of vitamin K-containing food on a week-to-week basis,” not to eat large amounts of leafy green vegetables, and to talk to the doctor before changing their diet (American Society of Health-System Pharmacists, 2026). A client on insulin or a sulfonylurea keeps the prescriber informed before a substantial change in eating. In each case the prescriber is involved before the change, not after.

People with a history of disordered eating

The searches for this page did not identify a study of the alkaline diet and eating disorders. The diet’s rules sort foods into good and bad groups, the strict versions remove whole food groups, and some followers test their urine to check compliance. As a precaution that is this page’s reading of the diet’s rules rather than a study finding, a client with a history of disordered eating involves the existing care team before following it.

People with kidney disease

Kidney care is the setting where the acid load of a diet matters clinically, and it is also where the diet’s foods can do harm. Needs depend on the stage of disease, laboratory results and dialysis. Many of the diet’s staples, including bananas, oranges, dried fruits, avocado, potatoes, beans, lentils, cooked spinach, and nuts and seeds, are on the National Kidney Foundation’s list of foods higher in potassium, and a person with high potassium may be advised to limit them (National Kidney Foundation, 2023). The kidney care team sets the plan.

People with cancer

A systematic review found no study of the alkaline diet or alkaline water for treating cancer (Fenton & Huang, 2016). Nutrition during cancer treatment belongs to the oncology team and an oncology dietitian.

Client misconceptions

Three beliefs come up most often. The first is that food can make the blood acidic or alkaline; in healthy people the lungs and kidneys keep blood pH in a narrow range, and diet changes urine pH far more than blood pH. The second is that a urine or saliva test strip shows the body’s pH; urine pH reflects what the kidneys are excreting, which is the body keeping its blood pH steady. The third is that an alkaline diet or alkaline water can prevent or cure cancer; a systematic review found no trial testing either, and cancer dietitians state that no scientific literature establishes a benefit for curing it. Section 6 gives each myth with its origin and sources.

🤝 COACHING CONNECTION

Maria tells her coach she has started the alkaline diet after her sister’s cancer diagnosis, drinks only alkaline water and checks her urine every morning. “Some mornings the strip says I’m acidic and I panic.” The coach reflects how much she wants to protect herself and asks what she has changed so far. Maria says she now cooks vegetables most nights and likes it. The coach asks what part she wants to keep and who she talks to about her own health. Maria decides to keep the vegetable dinners, to ask her doctor at her next appointment about the strips and the water, and to stop testing until then. The coach gives no advice about the diet and supports the plan Maria made.

4. The evidence

(select the heading to open or close this section)

The research does not support the diet’s central claim. Short trials in healthy adults show that eating mostly alkaline-forming foods raises the pH of urine by about 1 unit within days, while the reported between-diet blood-pH changes were small, about 0.01 to 0.014 units, with differing sample types, measurement conditions and analyses. Studies that score people’s usual diets by their estimated acid load find modest associations with type 2 diabetes and cancer, but they cannot separate acid load from the foods that produce it, and the trials of more fruit and vegetables did not detect a clear between-group difference in bone-turnover markers. The searches for this page did not identify a trial of the popular diet that measured heart attacks, strokes, cancer or death.

Four kinds of evidence are kept apart below, as the research itself keeps them apart: what the diet does to blood pH; what it does to urine pH; what scores of a diet’s acid load are associated with in large populations; and what happens to health outcomes when people are assigned to eat more alkaline-forming foods. A fifth body of research, on lowering the diet’s acid load in people with chronic kidney disease, is clinical care and is described separately.

Evidence from randomized controlled trials

The searches for this page did not identify a randomized trial of the popular alkaline diet as promoted in books, with its own food lists and claims. The trials found test study diets planned to have a low or a high acid load, or test adding fruit and vegetables. They are small and short: 3 crossover trials in which 8, 11 and 15 healthy adults were analyzed after 4-day periods of an alkalizing and an acidizing diet, each diet eaten twice in the first trial (Buclin et al., 2001; Limmer et al., 2018, 2020); one 12-week trial in 46 recreationally active adults (Hietavala et al., 2018); and 2 trials of eating more fruit and vegetables, one for 2 years in 276 postmenopausal women and one for 16 weeks in 83 older adults (Macdonald et al., 2008; Neville et al., 2014).

A trial assigns people to a diet by chance and compares them with people assigned to something else, which is the strongest way to test whether the diet itself causes a result.

Blood pH and urine pH

In the earliest of these trials, 8 healthy young men completed 4 sessions of 4 days each in an order set from a balanced randomized list, eating a diet rich in acid-forming foods twice and a diet providing base-forming foods twice, with similar calcium, phosphate, sodium, protein and calories. The experimental package included different mineral waters, including bicarbonate-rich water with the base-forming diet, and standardized calcium administration; serial venous samples were analyzed. Across those serial samples, blood pH differed by an average of 0.014 units between the diets and urine pH by 1.02 units, both in the expected direction; the authors report the overall diet effect from a repeated-measures analysis of variance that also included the calcium preparation and clock time (Buclin et al., 2001).

The diets in that trial also differed in potassium and chloride, which its authors name as possible confounding factors. A later systematic review rated the trial at high risk of bias for allocation concealment (Fenton et al., 2011).

A German crossover trial assigned 16 recreationally active young adults, in random order, to 4 days of an alkalizing diet and 4 days of an acidizing diet, chosen freely from a food list with instructions from a dietitian; 2 withdrew and 3 had incomplete data, so 11 were analyzed. Resting capillary blood pH was 7.46 after the acidizing diet and 7.47 after the alkalizing diet, a difference that was not statistically significant in a Wilcoxon test (p = 0.373). Urine pH was 5.5 after the acidizing diet and 7.0 after the alkalizing diet (Limmer et al., 2018).

The same group’s second trial analyzed 15 adults after the same 4-day diets. Under ordinary sea-level conditions, resting blood pH was 7.40 after the acidizing diet and 7.41 after the alkalizing diet, while blood bicarbonate was higher after the alkalizing diet (24.3 against 22.9 millimoles per liter). Urine pH was 5.64 after the acidizing diet and 6.54 after the alkalizing diet. After 12 hours of simulated altitude, resting blood pH before the sprint test was 7.41 and 7.43. The abstract reports a significant overall difference; Table 1 marks the between-diet post hoc difference under simulated altitude, not the sea-level comparison (Limmer et al., 2020).

The longest trial found ran 12 weeks. In Finland, 49 healthy adults aged 20 to 50 were randomly assigned to a low or a moderate acid load diet during a twice-weekly training program; 3 dropped out and 46 were analyzed. The low acid load group was advised to increase fruit and vegetables to 800 to 1,000 grams a day, and the moderate group to limit them to 200 to 300 grams. Net acid excretion in urine was lower on the low acid load diet, but the trial did not detect a statistically clear between-group difference in capillary blood pH, shown only in figures. Urine pH, estimated with test strips, did not change significantly, and the strip results were not presented (Hietavala et al., 2018).

Taken together, these trials agree on the direction of the urine change. Changing what healthy people eat for days to weeks changes how much acid the kidneys excrete and how acidic the urine is, by about 0.9 to 1.5 pH units in the 4-day trials. The reported between-diet blood-pH changes were small, about 0.01 to 0.014 units in the short crossover experiments. Sample type, measurement conditions and analyses differed. These results do not establish that the popular alkaline diet prevents or treats disease.

A population study of 22,034 adults aged 39 to 78 in England found the same pattern in everyday eating: diets lower in acid load, higher in fruit and vegetables and lower in meat went with more alkaline urine, “with a magnitude similar to intervention studies” (Welch et al., 2008). The rating table carries this page’s own judgments for both outcomes: blood pH is not rated against a threshold, and urine pH is rated low, provisionally, and is not a disease outcome.

Exercise performance

Because sodium bicarbonate taken as a supplement can improve very intense exercise, researchers have asked whether an alkalizing diet does the same. In the first German trial, the 400-meter run was about 1.5 seconds faster after the alkalizing diet than after the acidizing diet (65.8 against 67.3 seconds; p = 0.026), and post-race blood lactate was higher (Limmer et al., 2018). The trial was small, used hand timing, and did not record how much people ate; the authors list both as limitations, so a difference in energy or carbohydrate between the diets cannot be ruled out. In the second trial, the authors found “no differences between BASE and ACID conditions” for any measure of a 60-second all-out tethered sprint, at sea level or after simulated altitude (Limmer et al., 2020). These are 2 different tests and are not combined.

Bone health

Bone is the outcome the acid-ash hypothesis was built around: the idea is that the skeleton gives up calcium salts to neutralize dietary acid. In a 2-year Scottish trial, 276 postmenopausal women aged 55 to 65 were randomly assigned to high-dose or low-dose potassium citrate, a placebo capsule, or 300 grams of extra fruit and vegetables a day, an amount chosen to supply about as much alkali as the low dose. The trial did not detect a clear between-group difference in bone-turnover markers over 2 years, and reported no significant difference in spine bone density loss between placebo and the treatment groups (Macdonald et al., 2008). These four-group comparisons do not establish that the groups were equivalent, and the potassium citrate results are not transferred to the fruit and vegetable group.

A 2011 systematic review describes it as finding no effect of either the potassium citrate or the extra fruit and vegetables on bone mineral density (Fenton et al., 2011). The full report was read for the outside review of this page.

In Northern Ireland, 83 adults aged 65 to 85 who usually ate 2 or fewer portions of fruit and vegetables a day were randomly assigned to continue or to eat 5 or more portions a day for 16 weeks, with the produce delivered free; 82 completed the trial. The trial did not detect a clear between-group difference in bone-turnover markers, serum osteocalcin and C-terminal telopeptide, which were secondary outcomes of a trial designed mainly to study immune function (Neville et al., 2014).

The broadest assessment found is the 2011 systematic review, which applied criteria for judging causation to 22 randomized trials, 2 meta-analyses and the prospective cohorts in healthy adults (11 in its abstract, 12 in its results). Calcium in the urine rose with the diet’s acid load, as the hypothesis predicts, but calcium balance studies did not show the body losing calcium overall; none of the randomized trials reported fractures or bone strength. The review concluded that “a causal association between dietary acid load and osteoporotic bone disease is not supported by evidence and there is no evidence that an alkaline diet is protective of bone health” (Fenton et al., 2011).

Not every reviewer agrees. A 2018 review argues that published data support both proponents and opponents of the hypothesis (Frassetto et al., 2018). The short metabolic trial described above found 74 percent more calcium and 19 percent more of a marker of bone breakdown in the urine on the acid-forming diet, which its authors read as calcium coming from bone (Buclin et al., 2001); a meta-analysis of such studies cautions that rising calcium in the urine “is not evidence that the source of the excreted calcium is bone or that this calciuria contributes to the development of osteoporosis” (Fenton et al., 2008).

Alkaline salts taken as supplements are a separate question from the diet: a 2026 review of 5 potassium citrate trials in 401 postmenopausal women found a lower urine marker of bone breakdown at 1 month but no significant effect on the other markers it pooled (AlSejari et al., 2026).

Cardiometabolic outcomes

The searches for this page did not identify a randomized trial of the popular alkaline diet that measured blood pressure, blood lipids, blood sugar or cardiovascular events. One small study in Turkey divided 32 sedentary women into 4 groups of 8 for 8 weeks: no change, walking exercise, a low acid load diet planned by a dietitian with calorie and acid load targets, or the diet plus exercise. LDL cholesterol and triglycerides fell most with the diet plus exercise (Yalcinkaya et al., 2023). The authors state that the study “could not be conducted as a randomized controlled study,” and the diet had calorie targets, so it cannot separate acid load from calories, food choices and exercise. The associations between acid load scores and diabetes and blood pressure come from cohort studies, described below.

Cancer

A 2016 systematic review searched published and unpublished literature to April 2015 for any randomized or observational study of dietary acid load, an alkaline diet or alkaline water and cancer. From 8,278 citations, only 1 study qualified: a cohort of male smokers in Finland, which found no clear association between estimated acid excretion and bladder cancer (odds ratio 1.15, 95 percent confidence interval 0.86 to 1.55). No randomized trial was found, and no study at all examined the diet or alkaline water as a cancer treatment. The authors concluded: “Promotion of alkaline diet and alkaline water to the public for cancer prevention or treatment is not justified” (Fenton & Huang, 2016).

Since then, cohort studies of acid load scores and cancer have been pooled; they are described in the cohort section below, because they are associations, not tests of the diet. A clinic in Japan has published retrospective reports of what it calls alkalization therapy alongside standard cancer treatment. In one, among 129 patients with advanced colorectal cancer, those whose urine pH stayed at 7.0 or higher lived longer in some subgroups (Suzuki et al., 2026). The abstract does not describe the therapy’s components, and a retrospective comparison of patients who reached a urine target with those who did not cannot show whether the therapy, the patients’ underlying health or other treatment explains the difference. This page read that report as its abstract.

Body weight, as measured

The searches for this page did not identify a trial that tested the alkaline diet for weight change. In the 12-week Finnish trial, there were no significant changes in measured body mass in either group (Hietavala et al., 2018). In the small Turkish study, body mass index fell by about 1.3 percent with the diet alone, 3.3 percent with exercise alone and 5.2 percent with both over 8 weeks, and rose by about 1.4 percent in the group that made no change; fat mass did not differ between groups (Yalcinkaya et al., 2023). The diet had calorie targets and the groups were not randomly assigned, which limits what the result says about acid load. The archive reports weight as a measurement, never as a goal; see the standing rule in the review record. Weight a person loses without meaning to is a reason to involve a clinician.

Mortality

The searches for this page did not identify a randomized trial of the alkaline diet or of alkaline water that reported deaths. Studies that relate acid load scores to death rates are observational and are described in the cohort section.

Kidney care, a separate clinical use

Lowering a diet’s acid load has a real clinical use, and it is a different thing from the popular diet. When kidney function declines, the kidneys may not remove enough acid, which is one cause of metabolic acidosis (MedlinePlus, 2025). In a 1-year trial in 71 people with stage 4 chronic kidney disease from high blood pressure and low blood total carbon dioxide (below 22 millimoles per liter), all taking an ACE inhibitor, fruit and vegetables dosed to cut dietary acid by half and sodium bicarbonate tablets both raised blood total carbon dioxide, bicarbonate more so; estimated kidney function after 1 year did not differ between the groups, and blood potassium did not rise in either (Goraya et al., 2013).

A 5-year trial by the same group in 153 people with high blood pressure and large amounts of protein in the urine reported slower decline in kidney function with fruit and vegetables or bicarbonate than with usual care (Goraya et al., 2024). Both were read as abstracts.

These trials were done in selected patients under nephrology care. A national kidney nutrition guideline, developed by the National Kidney Foundation with the Academy of Nutrition and Dietetics and graded with GRADE, covers dietary management of chronic kidney disease, including electrolytes (Ikizler et al., 2020); this page read its summary only and does not report its recommendations. None of this makes the popular alkaline diet a kidney treatment. For a person with kidney disease, whether to add fruit and vegetables, how much and which kinds is decided by the kidney care team, because many of the same foods are high in potassium (National Kidney Foundation, 2023). That clinical diet belongs to the broader topic Renal Diet.

Evidence from long-term prospective cohort studies

Cohort studies do not test the alkaline diet. They estimate the acid load of people’s usual diets from food questionnaires or records, using scores such as the potential renal acid load or the net endogenous acid production, and follow what happens to people with higher and lower scores. A high score means more meat, cheese and grain foods relative to fruit and vegetables. These studies can show that a pattern goes with an outcome; they cannot by themselves show that acid load caused it, and they cannot separate acid load from everything else that differs between people who eat more meat and people who eat more vegetables. The authors of the cancer review note that the GRADE working group treats observational associations as weak evidence unless the risk is at least doubled with no concerns about confounding (Fenton & Huang, 2016).

A 2025 review assembled the whole body of observational research: 118 studies (31 cohort, 22 case-control and 65 cross-sectional) covering 38 outcomes and about 1 million participants. It graded the credibility of each association with predefined criteria built from the pooled estimate and its confidence interval, the prediction interval, heterogeneity, small-study effects and excess significance bias. Associations with type 2 diabetes reached its highest class, “convincing (class I),” for both scores, and overall cancer reached class I for one score and “highly suggestive” (class II) for the other. The authors caution that “some of the associations were graded as weak” and that the studies are observational (Abbastabar et al., 2025).

It is a systematic review and meta-analysis of observational studies using a credibility classification: it pooled primary observational studies rather than published meta-analyses. Its full outcome table confirms the class assignments, which are carried exactly in the rating table as credibility classes, not GRADE ratings. The overall cancer result also shows that a class cannot be transferred from one acid load score to the other.

Cardiometabolic outcomes

For type 2 diabetes, a 2018 meta-analysis of 7 cohorts with 319,542 participants and 17,986 new cases found that each 5-unit higher potential renal acid load score went with a 4 percent higher risk (relative risk 1.04, 95 percent confidence interval 1.01 to 1.06), and each 5-unit higher net endogenous acid production score with a 3 percent higher risk (1.03, 1.01 to 1.04). Heterogeneity was high for the first score, the relation appeared U-shaped rather than straight for that score, the positive association was seen among women but not men, and the authors note the small number of studies (Jayedi & Shab-Bidar, 2018). The 2025 credibility review also reports a class II association between one score and systolic blood pressure (Abbastabar et al., 2025). The diabetes meta-analysis was read as its abstract.

Cancer

A 2022 meta-analysis of 10 observational studies, 6 cohorts and 4 case-control studies with 227,253 participants, found a higher risk of cancer with a high dietary acid load (relative risk 1.58, 95 percent confidence interval 1.23 to 2.05, from 7 studies) and a poorer prognosis after diagnosis (1.53, 1.10 to 2.13, from 3 studies), with substantial heterogeneity (Wang et al., 2022). This page read it as its abstract. These are associations with a diet score, not tests of an alkaline diet, and they do not show that eating alkaline-forming foods treats or prevents cancer.

Bone and fractures

A 2025 meta-analysis pooled 6 European studies, 5 cohorts followed for 6 to 18 years and 1 cross-sectional study, with 77,845 adults aged 39 to 82 and 5,275 fractures. The highest compared with the lowest dietary acid load category went with an odds of fracture 10 percent higher, with an interval from 1 percent lower to 21 percent higher (odds ratio 1.10, 0.99 to 1.21), so no association cannot be ruled out; the 5 cohorts alone gave 1.12 (1.03 to 1.22), and the cross-sectional study pointed the other way (Mirzababaei et al., 2025).

The pooled analysis combined 11 estimates from the 6 studies, including multiple estimates from some cohorts; their independence needs to be checked before interpreting the pooled precision. The interval tests whether there is any association; it is not evidence that the association is negligible. This page read the full open-access text, and the rating table carries its own Very low GRADE rating for the pooled association.

Mortality

A 2026 meta-analysis pooled 6 prospective cohort studies of general populations and clinical groups, with diet measured once at baseline by memory-based methods and follow-up that varied from study to study; some of the original relationships were U-shaped. For each 10 milliequivalents a day higher potential renal acid load score, the review’s reported pooled odds ratio for death from any cause was 1.03 (95 percent confidence interval 1.01 to 1.05), with moderate heterogeneity; the review calls the pooled measure an odds ratio although its methods describe included hazard ratios. The other score, net endogenous acid production, showed no clear association (1.00, 0.96 to 1.05). The authors call for “well-designed interventional studies” to test the association (Hajizadeh-Sharafabad et al., 2026). A relative ratio does not give a common absolute risk across these different populations, and the rating table rates the reported association, not the alkaline diet.

Evidence from case reports

Case reports show that a harm happened; they cannot show how often. Two are directly relevant. Between August 2020 and February 2021, 3 infants in New Jersey, Pennsylvania and Delaware were treated for severe low blood calcium and vitamin D-deficient rickets after being fed homemade formulas their parents described as the alkaline diet; one infant of 4 months had repeated cardiac arrests and brain injury, and another of 9 months had growth and developmental delays and iodine deficiency. The report’s authors note that recipes associated with the diet lack “essential vitamins and micronutrients such as vitamin D, calcium, and iodine” (Calello et al., 2021).

In a pediatric case report, a child with chronic kidney disease who was taking calcium carbonate as a phosphate binder developed high blood calcium, metabolic alkalosis and worsening kidney injury over several months; the cause was traced to the family’s use of alkaline water as an everyday drink, and kidney function and blood chemistry returned to baseline when it was stopped. The authors describe it as calcium-alkali syndrome, from alkaline water “in conjunction with calcium carbonate as a phosphate binder” (Kermond et al., 2022). Neither report says anything about healthy adults who eat more vegetables; both say a great deal about who needs a clinician involved.

Highlighted studies

These 4 studies carry the most weight for this page’s ratings and summary. Each is described so a reader can judge it without opening the paper.

On a narrow screen, scroll the table sideways to see every column.

Highlighted studies for the Alkaline Diet

Study	Design	Sample size	Duration	Finding	The limitation that matters
Limmer et al., 2018	Randomized crossover trial, single-blind (assessors blinded)	16 enrolled, 11 analyzed	4 days on each diet, tests 1 week apart	Resting blood pH 7.46 after the acidizing diet and 7.47 after the alkalizing diet (not significant); urine pH 5.5 and 7.0; 400-meter run about 1.5 seconds faster after the alkalizing diet	Very small, with 5 of 16 not analyzed, hand timing, and no record of how much people ate, so energy or carbohydrate could explain the run times
Hietavala et al., 2018	Randomized parallel trial	49 assigned, 46 analyzed	12 weeks, with twice-weekly training	Lower net acid excretion on the low acid load diet; did not detect a statistically clear between-group difference in capillary blood pH	Recreationally active adults in a training program; blood pH shown only in figures, so the difference cannot be given as a number
Macdonald et al., 2008	Randomized controlled trial with 4 groups, including 300 grams a day of extra fruit and vegetables	276 postmenopausal women	2 years	Did not detect a clear between-group difference in bone-turnover markers; no significant difference in spine bone density loss between placebo and the treatment groups	Not a test of equivalence; the fruit and vegetable group was single-blind, unlike the double-blind capsule groups, and the trial did not measure fractures
Fenton & Huang, 2016	Systematic review of trials and observational studies of acid load, alkaline diets or alkaline water and cancer	8,278 citations screened; 1 study included	Literature to April 2015	No randomized trial found; no study of treatment; no clear association of estimated acid excretion with bladder cancer in 1 cohort	Searches predate the newer cohort studies of acid load scores and cancer

Head to head

The searches for this page did not identify a trial that compared the popular alkaline diet with another named diet, such as the DASH Diet, the Mediterranean Diet or the Vegan Diet. The trials found compare an alkalizing study diet with an acidizing one, which tests the acid load idea under controlled conditions rather than the diet as promoted. In kidney disease, trials compared fruit and vegetables with sodium bicarbonate tablets and with usual care (Goraya et al., 2013, 2024); those are comparisons of treatments planned by a kidney team, not of popular diets.

Where the evidence is absent

The searches for this page, logged in its search record, did not identify the following: a randomized trial of the popular alkaline diet as promoted, with its own food lists; any trial of the diet or of alkaline water that measured heart attacks, strokes, cancer or death; any trial of the diet or of alkaline water for treating cancer (Fenton & Huang, 2016, found none to April 2015, and the searches for this page did not identify any since); a trial of more than 2 years; a trial that measured fractures; and any study of what happens after people stop. Separate searches did not identify a trial of the diet in pregnancy or breastfeeding, in children, or in people with a history of disordered eating; for older adults, only the 16-week fruit and vegetable trial; and for athletes, only small trials of 4-day study diets.

Several gaps are about measurement rather than missing studies. The blood pH trials are very small, and one reports blood pH only in figures. The cohort studies all estimate acid load from questionnaires or records, and none can separate acid load from the foods behind it. The searches for this page did not identify a study that measured what the diet costs, how long people stay on it, or its environmental footprint. A 2026 review of the alkaline water literature concludes that claims of “systemic alkalinization, immune enhancement, cancer prevention, or anti-aging effects remain unsupported” (Alebrahim et al., 2026).

5. Mechanisms

(optional reading; select the heading to open or close this section)

This section explains how the diet is thought to work in the body. You can skip it. Nothing in the coaching sections depends on it.

Established mechanisms

The body keeps blood pH in a narrow range. In healthy people, blood pH stays between about 7.35 and 7.45 (Frassetto et al., 2018). Chemical buffers in the blood, chiefly bicarbonate, absorb acid or base as it appears; the lungs adjust how much carbon dioxide is breathed out; and the kidneys excrete acid and regulate bicarbonate (Hietavala et al., 2018). British cancer dietitians put it plainly: “Blood pH (7.4) is tightly regulated by the kidneys and respiratory system. Any excess acid is excreted in the urine” (British Dietetic Association Oncology Specialist Group, 2021). Metabolic acidosis, too much acid in the body fluids, is a medical condition with causes such as kidney disease, uncontrolled diabetes, severe diarrhea and some poisonings, not a result of choosing a steak over a salad (MedlinePlus, 2025).

Food changes the acid the kidneys excrete. Protein foods, especially those rich in sulfur-containing amino acids, and phosphorus add acid when they are metabolized; fruit and vegetables supply potassium and organic anions such as citrate that are metabolized to base (Frassetto et al., 2018; Remer & Manz, 1995). The potential renal acid load sums those effects for a food or a day’s eating, and the estimate tracks how much acid the kidneys excrete and how acidic the urine is (Remer & Manz, 1995). That is why the trials in section 4 find large changes in urine pH and only small changes in blood bicarbonate and blood pH: the kidneys are doing their job.

Urine calcium rises with acid excretion. When net acid excretion rises, so does calcium in the urine (Fenton et al., 2008, 2011). Whether that calcium comes from bone is the disputed part, described below.

Proposed mechanisms

Bone as a buffer. Some researchers propose that bone, which holds large amounts of alkaline calcium salts, gives up some of them to neutralize the diet’s acid load over years, so that a high acid load slowly drains the skeleton (Frassetto et al., 2018). Calcium balance studies, which measure everything that goes in and out, did not show the body losing calcium overall with more acid excretion, and the laboratory studies in which acid dissolved bone were run at pH 7.2 or lower, below the range found in healthy blood (Fenton et al., 2011). The reviewers found “no evidence to support the suggestion that the very small systemic pH changes (< 0.02 pH units) seen in response to diet” affect the cells that break down bone (Fenton et al., 2011). The mechanism is proposed, not established, and it does not support a claim in section 4.

Acid and tumors. Some cancer cells and tumors grow well in an acidic environment in the laboratory, and promoters have built on that to claim that an alkaline diet starves cancer (Fenton & Huang, 2016). The same review notes that cancer organizations have stated that the body tightly regulates systemic pH and that food choices affect urine pH, not body acidity (Fenton & Huang, 2016). British cancer dietitians note that “neither cancer cells nor healthy cells can survive in an alkaline environment” (British Dietetic Association Oncology Specialist Group, 2021). The searches for this page did not identify a trial that tested the idea in people.

Alkaline water and antioxidants. Sellers of ionized water describe it as hydrogen-rich or as having antioxidant potential because of a negative oxidation-reduction potential. A 2026 review notes that a negative oxidation-reduction potential “is not a reliable proxy for dissolved molecular hydrogen” and that evidence for metabolic, antioxidant and immune benefits is inconsistent (Alebrahim et al., 2026). The same review describes mineral-rich alkaline waters as able to “transiently increase urinary pH in vivo without changing systemic blood pH” (Alebrahim et al., 2026).

6. Risks, contraindications and myths

(select the heading to open or close this section)

Warnings from professional or regulatory bodies

The U.S. Food and Drug Administration advises parents and caregivers “to not make or feed homemade infant formula to infants” (U.S. Food and Drug Administration, 2021a); the 3 infants described in section 4 had been fed homemade formulas their parents described as the alkaline diet (Calello et al., 2021). In the “Real Water” investigation, the agency told consumers, restaurants, distributors and retailers not to “drink, cook with, sell, or serve” that brand of alkaline water (U.S. Food and Drug Administration, 2021b).

The British Dietetic Association’s Oncology Specialist Group states: “Blood pH is not altered by dietary intake,” and “There is no scientific literature establishing the benefit of an alkaline diet for curing cancer” (British Dietetic Association Oncology Specialist Group, 2021). In 2021, staff of the U.S. Federal Trade Commission sent Enagic USA a cease-and-desist demand over claims by its business opportunity participants or representatives that Kangen Water could prevent or treat COVID-19 (Federal Trade Commission, 2021). The United Kingdom’s Advertising Standards Authority found a seller’s claims that alkaline water could “neutralise excess tissue acidity and neutralise damaging free radicals” misleading in the absence of robust evidence (Advertising Standards Authority, 2013). The authors of the cancer systematic review concluded that promotion of the diet and alkaline water “for cancer prevention or treatment is not justified” (Fenton & Huang, 2016); that is a review’s conclusion, not a regulator’s ruling.

Nutrient gaps

A version that keeps a little dairy, fish, eggs, beans and whole grains looks much like other plant-forward patterns and need not leave gaps. The strict versions are different. Removing dairy foods, grains and all animal protein makes calcium, vitamin D, iodine and protein harder to get, and the homemade infant formulas in the case reports lacked exactly vitamin D, calcium and iodine (Calello et al., 2021). The Heart Association’s guidance asks for whole grains and healthy protein sources (Lichtenstein et al., 2026), which the strictest lists remove. A version with no animal foods at all also raises the planning questions, such as vitamin B12, that the Vegan Diet page covers. A registered dietitian can check a particular plan.

Who should not follow it without medical supervision

People with chronic kidney disease, a kidney transplant or a history of high potassium, because many of the diet’s foods are high in potassium and needs depend on stage, laboratory results and dialysis (National Kidney Foundation, 2023); and especially people with kidney disease taking calcium-based phosphate binders who are thinking of drinking alkaline water (Kermond et al., 2022). People taking ACE inhibitors or potassium-sparing diuretics (Office of Dietary Supplements, 2021), warfarin (American Society of Health-System Pharmacists, 2026), or insulin or a sulfonylurea. People with cancer, whose treatment belongs to the oncology team. Infants, children and adolescents, and anyone pregnant or breastfeeding. People with a history of disordered eating, as a precaution this page draws from the diet’s rules.

Medication interactions

Potassium: ACE inhibitors and potassium-sparing diuretics reduce the potassium lost in urine and “can make potassium levels too high, especially in people who have kidney problems,” while loop and thiazide diuretics increase potassium loss (Office of Dietary Supplements, 2021). A sharp rise in high-potassium fruit and vegetables matters most for people on the first group of medicines who also have kidney disease. Vitamin K: people taking warfarin are told to eat consistent amounts of vitamin K-containing foods and not to eat large amounts of leafy green vegetables (American Society of Health-System Pharmacists, 2026), and many alkaline lists put leafy greens first. Calcium and alkali: alkaline water taken with calcium carbonate as a phosphate binder was the combination in the calcium-alkali case (Kermond et al., 2022). A coach never adjusts medication; the point of listing these is to know when to send the client back to the prescriber.

Signs it is going wrong

Physical symptoms belong to the client’s care plan or a clinician: muscle weakness, an irregular or pounding heartbeat, confusion, unusual tiredness, nausea, swelling, or dizziness, any of which can come from potassium, calcium or acid-base problems in a person with kidney disease or on the medicines above; metabolic acidosis itself can bring confusion or lethargy (MedlinePlus, 2025). Severe symptoms, or symptoms that come on fast, need emergency help.

A client taking insulin or a sulfonylurea who has symptoms of a possible low blood sugar episode follows their own treatment plan immediately, gets emergency help for severe symptoms or an episode they cannot manage, and tells the prescriber once the episode is addressed, without waiting for a coaching discussion. Weight a person loses without meaning to is a reason to involve a clinician. In an infant, stiffening, breathing pauses, turning blue or becoming unresponsive, signs described in the case report, need emergency care (Calello et al., 2021).

Eating behaviors are a separate question. A coach can notice and ask what a behavior is for: testing urine every morning, refusing family meals, or dropping whole food groups may reflect worry, curiosity, a household’s preferences, cost or a cultural practice, and many people who check a strip once and move on are not in difficulty. The concern is a behavior that causes distress, narrows what the person eats, or gets in the way of daily life. A real concern goes through the coach’s own referral process, or to the client’s clinician under an existing care plan. The coach does not diagnose from a behavior alone.

Myths and where they came from

Myth: “Eating acidic foods makes my blood acidic.”

This comes from the acid-ash hypothesis and from marketing that blurs the pH of urine with the pH of blood (Fenton & Huang, 2016). In short crossover experiments, 4-day periods of very different study diets changed urine pH by about 1 unit, while the reported between-diet blood-pH changes were small, about 0.01 to 0.014 units; sample type, measurement conditions and analyses differed (Buclin et al., 2001; Limmer et al., 2018, 2020). The kidneys and lungs hold blood pH steady (Frassetto et al., 2018).

Myth: “My urine strip shows my body is too acidic.”

Promoters encourage people to test urine or saliva as a measure of the body’s acidity (Fenton & Huang, 2016). Urine pH reflects what the kidneys are excreting after a meal or a day’s eating; acidic urine after a high-protein meal shows the kidneys removing acid, not a body that has become acidic (Remer & Manz, 1995; Welch et al., 2008).

Myth: “An alkaline diet or alkaline water can cure cancer.”

This rests on laboratory findings that some tumors thrive in acid, extended to the whole body (Fenton & Huang, 2016). A systematic review found no trial of the diet or alkaline water for preventing or treating cancer, and cancer dietitians state that “There is no scientific literature establishing the benefit of an alkaline diet for curing cancer” (British Dietetic Association Oncology Specialist Group, 2021; Fenton & Huang, 2016).

Myth: “Acid-forming foods dissolve my bones.”

This is the bone version of the acid-ash hypothesis; urine calcium does rise with acid excretion. But calcium balance studies did not show overall calcium loss, the trials of extra fruit and vegetables did not detect a clear between-group difference in bone-turnover markers, and a systematic review found “no evidence that an alkaline diet is protective of bone health” (Fenton et al., 2011; Macdonald et al., 2008; Neville et al., 2014).

Myth: “Alkaline water neutralizes acid in my tissues.”

This is a seller’s claim; a British advertising regulator found one such claim misleading in the absence of robust evidence (Advertising Standards Authority, 2013). A 2026 review found that claims of “systemic alkalinization” remain unsupported (Alebrahim et al., 2026).

7. Key terms

Acid-base balance

The body’s control of how acidic or alkaline its fluids are, kept in a narrow range by chemical buffers, the lungs and the kidneys.

pH

A scale of acidity from 0 to 14 on which 7 is neutral, lower numbers are more acidic and higher numbers more alkaline; each whole unit is a tenfold change.

Acid-ash hypothesis

The older idea that foods leave an acid or alkaline residue after the body uses them, and that an acid residue harms health.

Potential renal acid load (PRAL)

A calculation from a food’s protein, phosphorus, potassium, magnesium and calcium that estimates how much acid it leaves for the kidneys to excrete; negative values mean the food leaves base.

Net endogenous acid production (NEAP)

Another estimate of a diet’s acid load, usually calculated from protein and potassium intake.

Dietary acid load

The overall acid a person’s usual diet is estimated to produce, as measured by scores such as PRAL or NEAP.

Net acid excretion

The amount of acid the kidneys remove in urine over a period, measured in the laboratory.

Bicarbonate

The main base buffer in blood; its level, measured in a blood test, is one sign of acid-base status.

Metabolic acidosis

A medical condition in which there is too much acid in the body fluids, with causes such as kidney disease, uncontrolled diabetes or poisoning.

Alkaline water

Water with a pH above 7, either naturally rich in minerals or made with an ionizing machine.

Calcium-alkali syndrome

High blood calcium, metabolic alkalosis and kidney injury caused by taking in too much absorbable calcium together with alkali.

Bone turnover markers

Substances in blood or urine that reflect how fast bone is being broken down and rebuilt.

Crossover trial

A trial in which each participant receives both diets in random order, with a gap between, so each person serves as their own comparison.

Credibility class

A label from a systematic review and meta-analysis of observational studies that grades how convincing an observational association is from its size, precision, consistency and signs of bias; it is not a GRADE rating.

8. Review questions

1. What is the difference between what the alkaline diet asks people to eat and the reason it gives for eating that way?
2. In the 4-day trials, how much did urine pH change and how much did resting blood pH change, in whom, and what does that difference tell you about how the body works?
3. A client with chronic kidney disease says they have started drinking alkaline water and eating “as alkaline as possible.” What does the coach do, and where is the referral line?
4. Where did the idea that acid-forming foods dissolve bone come from, and what did the 2011 systematic review conclude about it?
5. A client asks whether their alkaline water machine was worth the money. How can a coach respond without endorsing or discouraging the purchase, and what does the coach make sure the client knows about who profits?

9. References

Abbastabar, M., Mohammadi-Pirouz, Z., Omidvar, S., Bakhtiari, A., Crowe, F. L., & Sepidarkish, M. (2025). Dietary acid load and human health: A systematic review and meta-analysis of observational studies. Nutrition Reviews, 83(9), 1641-1656. https://doi.org/10.1093/nutrit/nuae222

Advertising Standards Authority. (2013, July 3). ASA ruling on Water for Health Ltd (Complaint A13-221224). asa.org.uk/rulings/water-for-health-ltd-a13-221224.html

Alebrahim, H., Alsaei, A., Sefen, P., Hasan, M., Ramadhan, A., & Deen, G. R. (2026). The health benefits of alkaline water: Is it a fact or marketing myth? Frontiers in Medicine, 13, Article 1849818. https://doi.org/10.3389/fmed.2026.1849818

Aleksandrowicz, L., Green, R., Joy, E. J., Smith, P., & Haines, A. (2016). The impacts of dietary change on greenhouse gas emissions, land use, water use, and health: A systematic review. PLOS ONE, 11(11), Article e0165797. https://doi.org/10.1371/journal.pone.0165797

AlSejari, N., Alkhulaifi, N. S., Alenezi, R. S., Alharran, A. M., & Alsubaiei, A. A. (2026). Effects of potassium citrate supplementation on bone turnover markers in postmenopausal women: A GRADE-assessed systematic review, meta-analysis and trial sequential analysis. Calcified Tissue International, 117(1), Article 111. https://doi.org/10.1007/s00223-026-01569-9

American Society of Health-System Pharmacists. (2026, March 15). Warfarin. MedlinePlus, National Library of Medicine. medlineplus.gov/druginfo/meds/a682277.html

British Dietetic Association Oncology Specialist Group. (2021). Cancer diets: Myths and more. British Dietetic Association. bda.uk.com/static/1a9d5f92-aaab-4431-992e70a2abacaffd/BDA-OncologySG-A4-Cancer-Diets.pdf

Buclin, T., Cosma, M., Appenzeller, M., Jacquet, A. F., Décosterd, L. A., Biollaz, J., & Burckhardt, P. (2001). Diet acids and alkalis influence calcium retention in bone. Osteoporosis International, 12(6), 493-499. https://doi.org/10.1007/s001980170095

Calello, D. P., Jefri, M., Yu, M., Zarraga, J., Bergamo, D., & Hamilton, R. (2021). Notes from the field: Vitamin D-deficient rickets and severe hypocalcemia in infants fed homemade alkaline diet formula, three states, August 2020 to February 2021. MMWR. Morbidity and Mortality Weekly Report, 70(33), 1124-1125. https://doi.org/10.15585/mmwr.mm7033a4

City News Service. (2016, February 4). Author convicted of providing bogus treatments. 10News. 10news.com/news/valley-center-author-convicted-of-providing-bogus-treatments-to-terminally-ill

Dwyer, J., Foulkes, E., Evans, M., & Ausman, L. (1985). Acid/alkaline ash diets: Time for assessment and change. Journal of the American Dietetic Association, 85(7), 841-845. https://doi.org/10.1016/s0002-8223(21)03720-2

Enagic USA. (n.d.-a). Enagic USA: Home of Kangen Water. Retrieved November 8, 2026, from enagic.com

Enagic USA. (n.d.-b). Leveluk K8. Retrieved November 8, 2026, from enagic.com/en_US/products/leveluk-k8

Enagic USA. (n.d.-c). How to buy Enagic products. Retrieved November 8, 2026, from enagic.com/en_US/products/how-to-buy

Enagic USA. (n.d.-d). Business opportunity: Why become an Enagic Independent Distributor. Retrieved November 8, 2026, from enagic.com/en_US/business-opportunity

Essentia Water. (n.d.). Essentia Water. Retrieved November 8, 2026, from essentiawater.com

Federal Trade Commission. (2021, December 9). Letter to Enagic USA, Inc.: Cease and desist demand; unsubstantiated claims for coronavirus prevention and treatment. ftc.gov/legal-library/browse/warning-letters/letter-enagic-usa-inc. Letter PDF: ftc.gov/system/files/warning-letters/cease_and_desist_letter_to_enagic_usa_inc._dba_kangen_12.9.21.pdf

Fenton, T. R., Eliasziw, M., Lyon, A. W., Tough, S. C., & Hanley, D. A. (2008). Meta-analysis of the quantity of calcium excretion associated with the net acid excretion of the modern diet under the acid-ash diet hypothesis. American Journal of Clinical Nutrition, 88(4), 1159-1166. https://doi.org/10.1093/ajcn/88.4.1159

Fenton, T. R., & Huang, T. (2016). Systematic review of the association between dietary acid load, alkaline water and cancer. BMJ Open, 6(6), Article e010438. https://doi.org/10.1136/bmjopen-2015-010438

Fenton, T. R., Tough, S. C., Lyon, A. W., Eliasziw, M., & Hanley, D. A. (2011). Causal assessment of dietary acid load and bone disease: A systematic review & meta-analysis applying Hill’s epidemiologic criteria for causality. Nutrition Journal, 10, Article 41. https://doi.org/10.1186/1475-2891-10-41

Frassetto, L., Banerjee, T., Powe, N., & Sebastian, A. (2018). Acid balance, dietary acid load, and bone effects: A controversial subject. Nutrients, 10(4), Article 517. https://doi.org/10.3390/nu10040517

Goraya, N., Madias, N. E., Simoni, J., Kahlon, M., Aksan, N., & Wesson, D. E. (2024). Kidney and cardiovascular protection using dietary acid reduction in primary hypertension: A five-year, interventional, randomized, control trial. American Journal of Medicine, 137(11), 1114-1127.e8. https://doi.org/10.1016/j.amjmed.2024.06.006

Goraya, N., Simoni, J., Jo, C. H., & Wesson, D. E. (2013). A comparison of treating metabolic acidosis in CKD stage 4 hypertensive kidney disease with fruits and vegetables or sodium bicarbonate. Clinical Journal of the American Society of Nephrology, 8(3), 371-381. https://doi.org/10.2215/CJN.02430312

Hajizadeh-Sharafabad, F., Shojaei-Zarghani, S., Sharifi-Zahabi, E., Najafi, N., & Pashaei, M. R. (2026). Dietary acid load and the risk of all-cause mortality: A systematic review and meta-analysis of observational studies. Nutrition Reviews, 84(4), 684-692. https://doi.org/10.1093/nutrit/nuaf060

Hietavala, E. M., Ihalainen, J. K., Frassetto, L. A., Schumann, M., Eklund, D., Pitkänen, H., Häkkinen, K., & Mero, A. A. (2018). Effects of 12-week low or moderate dietary acid intake on acid-base status and kidney function at rest and during submaximal cycling. Nutrients, 10(3), Article 323. https://doi.org/10.3390/nu10030323

Ikizler, T. A., Burrowes, J. D., Byham-Gray, L. D., Campbell, K. L., Carrero, J. J., Chan, W., Fouque, D., Friedman, A. N., Ghaddar, S., Goldstein-Fuchs, D. J., Kaysen, G. A., Kopple, J. D., Teta, D., Yee-Moon Wang, A., & Cuppari, L. (2020). KDOQI clinical practice guideline for nutrition in CKD: 2020 update. American Journal of Kidney Diseases, 76(3, Suppl. 1), S1-S107. https://doi.org/10.1053/j.ajkd.2020.05.006

Jayedi, A., & Shab-Bidar, S. (2018). Dietary acid load and risk of type 2 diabetes: A systematic review and dose-response meta-analysis of prospective observational studies. Clinical Nutrition ESPEN, 23, 10-18. https://doi.org/10.1016/j.clnesp.2017.12.005

Kermond, R., Carter, S., & Quinlan, C. (2022). A child presents with acute kidney injury, alkalosis and hypercalcaemia, a new-age cause for a historical syndrome: Answers. Pediatric Nephrology, 37(8), 1807-1810. https://doi.org/10.1007/s00467-022-05465-w

Lichtenstein, A. H., Khera, A., Anderson, C. A. M., Appel, L. J., DeSilva, D. M., Gardner, C., Hu, F. B., Jones, D. W., Petersen, K. S., & American Heart Association. (2026). 2026 dietary guidance to improve cardiovascular health: A scientific statement from the American Heart Association. Circulation, 153(18), e1285-e1295. https://doi.org/10.1161/CIR.0000000000001435

Limmer, M., Eibl, A. D., & Platen, P. (2018). Enhanced 400-m sprint performance in moderately trained participants by a 4-day alkalizing diet: A counterbalanced, randomized controlled trial. Journal of the International Society of Sports Nutrition, 15(1), Article 25. https://doi.org/10.1186/s12970-018-0231-1

Limmer, M., Sonntag, J., de Marées, M., & Platen, P. (2020). Effects of an alkalizing or acidizing diet on high-intensity exercise performance under normoxic and hypoxic conditions in physically active adults: A randomized, crossover trial. Nutrients, 12(3), Article 688. https://doi.org/10.3390/nu12030688

Macdonald, H. M., Black, A. J., Aucott, L., Duthie, G., Duthie, S., Sandison, R., Hardcastle, A. C., Lanham New, S. A., Fraser, W. D., & Reid, D. M. (2008). Effect of potassium citrate supplementation or increased fruit and vegetable intake on bone metabolism in healthy postmenopausal women: A randomized controlled trial. American Journal of Clinical Nutrition, 88(2), 465-474. https://doi.org/10.1093/ajcn/88.2.465

MedlinePlus. (2025). Metabolic acidosis. National Library of Medicine. medlineplus.gov/ency/article/000335.htm

Mirzababaei, A., Daneshvar, M., Basirat, V., Asbaghi, O., & Daneshzad, E. (2025). Association between dietary acid load and risk of osteoporotic fractures in adults: A systematic review and meta-analysis of observational studies. BMC Musculoskeletal Disorders, 26(1), Article 266. https://doi.org/10.1186/s12891-025-08495-1

National Kidney Foundation. (2023, May 5). Potassium in your CKD diet. kidney.org/kidney-topics/potassium-your-ckd-diet

Neville, C. E., Young, I. S., Gilchrist, S. E., McKinley, M. C., Gibson, A., Edgar, J. D., & Woodside, J. V. (2014). Effect of increased fruit and vegetable consumption on bone turnover in older adults: A randomised controlled trial. Osteoporosis International, 25(1), 223-233. https://doi.org/10.1007/s00198-013-2402-x

Office of Dietary Supplements. (2021, March 22). Potassium: Fact sheet for consumers. National Institutes of Health. ods.od.nih.gov/factsheets/Potassium-Consumer

Remer, T., & Manz, F. (1995). Potential renal acid load of foods and its influence on urine pH. Journal of the American Dietetic Association, 95(7), 791-797. https://doi.org/10.1016/s0002-8223(95)00219-7

Stone, K. (2017, April 12). ‘pH Miracle’ author admits he’s no MD, microbiologist or ‘trained scientist.’ Times of San Diego. timesofsandiego.com/crime/2017/04/12/ph-miracle-author-admits-hes-no-md-microbiologist-or-trained-scientist

Suzuki, K., Kachi, S., Hamaguchi, R., Morikawa, H., & Wada, H. (2026). Association of alkalization therapy with long-term survival in stage IV or recurrent colorectal cancer: Interaction with RAS mutation status. Frontiers in Oncology, 16, Article 1867616. https://doi.org/10.3389/fonc.2026.1867616

U.S. Food and Drug Administration. (2021a, February 24). FDA advises parents and caregivers to not make or feed homemade infant formula to infants. fda.gov/food/alerts-advisories-safety-information/fda-advises-parents-and-caregivers-not-make-or-feed-homemade-infant-formula-infants

U.S. Food and Drug Administration. (2021b). Investigation of acute non-viral hepatitis illnesses: “Real Water” brand alkaline water (March 2021). fda.gov/food/outbreaks-foodborne-illness/investigation-acute-non-viral-hepatitis-illnesses-real-water-brand-alkaline-water-march-2021

Wang, R., Wen, Z. Y., Liu, F. H., Wei, Y. F., Xu, H. L., Sun, M. L., Zhao, Y. H., Gong, T. T., Wang, H. H., & Wu, Q. J. (2022). Association between dietary acid load and cancer risk and prognosis: An updated systematic review and meta-analysis of observational studies. Frontiers in Nutrition, 9, Article 891936. https://doi.org/10.3389/fnut.2022.891936

Welch, A. A., Mulligan, A., Bingham, S. A., & Khaw, K. T. (2008). Urine pH is an indicator of dietary acid-base load, fruit and vegetables and meat intakes: Results from the European Prospective Investigation into Cancer and Nutrition (EPIC)-Norfolk population study. British Journal of Nutrition, 99(6), 1335-1343. https://doi.org/10.1017/S0007114507862350

Yalcinkaya, N., Isik, O., Beyleroglu, M., Erdogdu, D., Cicek, G., & Novak, D. (2023). Effects of 8-week alkaline diet and aerobic exercise on body composition, aerobic performance, and lipid profiles in sedentary women. Frontiers in Nutrition, 10, Article 1339874. https://doi.org/10.3389/fnut.2023.1339874

Evidence rating and review record

Each row identifies the method, source, outcome and comparison being rated. Ratings from different tools are not interchangeable. The source is either a named published review or this page’s own judgment. The rating in the banner is for the diet’s central claim, that food changes the blood’s pH, and the banner names the tool that produced it. A high rating means the research is solid; it does not mean the diet is right for everyone, and it does not mean a coach should recommend it.

Rows rated with GRADE use the same 4-level scale as the clinical guidelines you will meet in practice. High means further research is very unlikely to change the conclusion. Moderate means further research may change it. Low means further research is likely to change it. Very low means the conclusion is uncertain. GRADE rates each outcome separately. A row marked Not rated is an abstention, not a certainty level.

Two rows carry credibility classes from Abbastabar et al. (2025), a different tool. It sorts observational associations into classes from I, convincing, through II, highly suggestive, III, suggestive, and IV, weak, to no association, using the size and precision of the pooled estimate, the prediction interval, heterogeneity and signs of small-study and excess significance bias. A convincing class means an association is statistically robust; it does not mean the association is causal, and it is not a GRADE level.

Three things about this table matter before reading it. The GRADE rows are this page’s own judgments, because the searches did not identify a published GRADE rating for these outcomes, and every interval this page calculated is labeled as an approximation that holds only under the assumption stated with it. The harms on this page are not rated, because they come from case reports, which show that a harm happened but cannot estimate how often. The kidney care trials are not rated here, because they test clinical treatment planned by a kidney team, which this page does not cover.

On a narrow screen, scroll the table sideways to see every column.

Evidence ratings, their sources and reasons

Outcome	Certainty	Who rated it, and for which comparison	Why it is rated this way
Resting blood pH after 4-day periods of a planned alkalizing diet compared with an acidizing diet (the banner)	Not rated for whether the change is below a clinically important threshold	GRADE assessment in progress, this page’s own decision; no published rating of this outcome was found. Comparison: study diets planned with acid load calculations to be alkalizing or acidizing, eaten in 4-day periods in random order by healthy young adults (Buclin et al., 2001, 8 men, each diet twice, serial venous samples on day 4; Limmer et al., 2018, 11 analyzed, resting capillary samples; Limmer et al., 2020, 15 analyzed, resting samples at sea level and after simulated altitude). The question is whether the change is smaller than a clinically important threshold; the previous version used 0.05 pH units.	Three small randomized crossover studies reported between-diet blood-pH differences of about 0.01–0.014 units after four-day dietary periods. Their measurements and analyses differed. The available results do not provide a verified interval for a common contrast against a justified clinically important threshold. This page therefore does not assign a GRADE level to the claim that the change is smaller than 0.05 units. These short experiments do not establish prevention or treatment of disease. The assessment so far, recorded in the claim ledger: randomized trials start at high; risk of bias is serious (in Limmer et al., 2018, 5 of 16 enrolled were not analyzed; a later review rated Buclin et al., 2001, at high risk of bias for allocation concealment), while participants’ knowledge of the diet is not counted because blood pH is a laboratory measure; the 3 differences point the same way; there is no indirectness deduction for the named study diets and participants; imprecision cannot be judged, because Buclin’s result comes from a repeated-measures model over serial samples, Limmer et al. (2018) used a rank test, and no paper reports an interval; and publication bias cannot be assessed with 3 small trials. Half the width of a population reference range is not a justified threshold for a between-diet change. Not rated here is an abstention, not the result of subtracting levels.
Urine pH after 4-day periods of a planned alkalizing diet compared with an acidizing diet	Low, provisional for an increase of at least 0.5 urine-pH units	GRADE, this page’s own judgment. Comparison: as in the row above; urine pH at the end of each 4-day period, or across serial collections in Buclin et al. (2001). Observed differences: 1.02 units (Buclin et al., 2001), 1.5 units (5.5 against 7.0; Limmer et al., 2018), and 0.90 units at sea level (5.64 against 6.54; Limmer et al., 2020). The question is whether the alkalizing diet raises urine pH by at least 0.5 units.	Randomized trials start at high. Lowered 1 level for risk of bias, for the reasons in the row above. Lowered 1 level for imprecision: no paper reports an interval, and the available model information does not resolve the uncertainty around the chosen size threshold. Treating the 2 diet periods as independent gives conditional approximate 95% intervals of about 0.83 to 2.17 (Limmer et al., 2018) and 0.51 to 1.29 (Limmer et al., 2020); these assume no within-person correlation, use a t distribution although the 2018 trial tested urine pH with a rank test, and are not the studies’ actual intervals. Such an approximation is wider than a paired interval only when that correlation is positive, which cannot be assumed; under the most adverse allowable correlation, the Limmer 2020 interval would be about 0.36 to 1.44, crossing 0.5. Buclin’s result comes from a repeated-measures model over serial collections, so no interval is derived from it. The 0.5-unit threshold is an operational convention taken from the urine-monitoring target the 2018 trial’s authors use (7.0 or above against 6.0 or below), not a health-benefit threshold. Not lowered for inconsistency: all 3 observed differences point the same way, though they vary in size. Not lowered for indirectness: the row names the study diets and people tested. Publication bias cannot be assessed with 3 small trials. High minus 2 gives low, provisional. Urine pH shows the kidneys excreting acid; it is not a disease outcome, and this label does not apply to any health claim.
Resting blood pH after 12 weeks of a low compared with a moderate acid load diet	Not rated	This page’s own decision. Comparison: 46 healthy, recreationally active adults aged 20 to 50 in a twice-weekly training program (Hietavala et al., 2018).	The paper reports that the trial did not detect a statistically clear between-group difference, but it shows blood pH only in figures, so there is no numeric estimate to compare with a threshold. Not rated means there is no usable estimate, not that there is no effect.
400-meter run time after 4 days of a planned alkalizing diet compared with an acidizing diet	Low	GRADE, this page’s own judgment. Comparison: 11 recreationally active young adults analyzed in a randomized crossover trial; 65.8 against 67.3 seconds, a difference of about 1.5 seconds favoring the alkalizing diet, p = 0.026 (Limmer et al., 2018). The question is whether the alkalizing diet shortens the run by at least 1 second.	Randomized trials start at high. Lowered 1 level for risk of bias: 5 of 16 enrolled were not analyzed; runs were hand-timed; and food amounts and energy intake were not recorded, so the diets may have differed in energy or carbohydrate as well as acid load, a route to bias in the comparison itself. Lowered 1 level for imprecision: the paper reports no interval; this page’s approximate 95% interval, back-calculated from the difference, p = 0.026 and 11 people, is 0.2 to 2.8 seconds, which includes differences below the 1-second threshold this page uses (about 1.5% of the race time). Inconsistency could not be judged from 1 trial. Not lowered for indirectness: the row names the population and test studied. Publication bias was not assessed. High minus 2 gives low. A second trial using a different test, a 60-second tethered sprint, did not find a difference (Limmer et al., 2020); the 2 are not combined.
60-second tethered sprint after 4 days of a planned alkalizing diet compared with an acidizing diet	Not rated	This page’s own decision. Comparison: 15 physically active adults in a randomized crossover trial, at sea level and after simulated altitude (Limmer et al., 2020).	The authors report no differences between diets for any sprint measure, but the results are given in figures and test statistics without between-diet estimates, so there is no estimate to compare with a threshold. Not rated is not a finding of no effect.
Bone turnover markers and bone density over 2 years, 300 grams a day of extra fruit and vegetables compared with a placebo capsule	Not rated	This page’s own decision. Comparison: 276 postmenopausal women aged 55 to 65 in a 4-group randomized trial (Macdonald et al., 2008).	The original reports were read. This combined row has not established a single outcome-specific fruit-and-vegetable versus control estimate and valid interval against a justified threshold. Macdonald’s four-group omnibus results and graphical bone-density results do not establish equivalence; turnover markers and bone density should be assessed separately if a grade is assigned. The potassium citrate results are not transferred to the fruit and vegetable group. The 16-week trial in older adults (Neville et al., 2014) did not detect a clear between-group difference in bone-turnover markers; that is not a finding of no effect.
Fractures or bone strength, alkaline diet or alkaline salts compared with control, in trials	Not rated	This page’s own decision. Comparison: any randomized trial in adults.	A systematic review found that none of 22 randomized trials reported fractures or bone strength (Fenton et al., 2011), and the searches for this page did not identify any since. There is no body of evidence to rate. Not rated is not a finding of no effect.
Fracture, highest compared with lowest dietary acid load score	Very low	GRADE, this page’s own judgment; the meta-analysis did not apply GRADE. Comparison: adults aged 39 to 82 in 5 European cohorts and 1 cross-sectional study, 77,845 people and 5,275 fractures, highest against lowest category of an acid load score; pooled odds ratio 1.10, 95% confidence interval 0.99 to 1.21 (Mirzababaei et al., 2025). The question is whether a higher score goes with any higher odds of fracture, so the threshold is an odds ratio of 1.0.	Observational studies start at low. Lowered 1 level for imprecision: the interval runs from 0.99 to 1.21 and so includes 1.0. That gives very low. Risk of bias is also a concern that cannot lower the rating further: the pooled analysis combined 11 estimates from 6 studies, including multiple estimates from some cohorts whose independence needs to be checked before interpreting the pooled precision, mixed hazard ratios with odds ratios, and included 1 cross-sectional study whose estimate pointed the other way; the 5 cohorts alone gave 1.12 (1.03 to 1.22). Statistical heterogeneity was low (I squared 12.9%). Not lowered for indirectness: the row names an acid load score, which the studies measured. Publication bias: Egger’s test was not significant (p = 0.291), but 6 studies are too few to judge it. Not raised for a dose-response pattern or a large association. The 1.0 threshold tests whether there is any association, not whether it is clinically important; the interval of 0.99 to 1.21 is not evidence of equivalence or of a clinically negligible association. An association with a score cannot show that acid load causes fractures.
Type 2 diabetes, higher compared with lower dietary acid load scores	Credibility class I, convincing	Credibility classification, Abbastabar et al. (2025), a systematic review and meta-analysis of observational studies using a credibility classification; not GRADE. Comparison: people with higher against lower potential renal acid load and net endogenous acid production scores; class I for both scores.	Carried exactly as published and confirmed from the review’s full outcome table. The tool grades how convincing an association is from the size and precision of the pooled estimate, its prediction interval, heterogeneity, small-study effects and excess significance bias; it does not judge whether the association is causal, and it is not GRADE. A separate dose-response meta-analysis of 7 cohorts found relative risks of 1.04 and 1.03 per 5-unit higher score (Jayedi & Shab-Bidar, 2018). This row describes a diet score, not the alkaline diet.
Overall cancer, higher compared with lower dietary acid load scores	Credibility class I, convincing (net endogenous acid production); class II, highly suggestive (potential renal acid load)	Credibility classification, Abbastabar et al. (2025); not GRADE. Comparison: people with higher against lower scores.	Carried exactly as published and confirmed from the review’s full outcome table, with the same meaning and limits as the row above. The 2 scores received different classes, so a class cannot be transferred from one score to the other. These are associations with a diet score; they are not evidence that an alkaline diet prevents or treats cancer.
Cancer prevention or treatment with the alkaline diet or alkaline water, compared with any control	Not rated	This page’s own decision. Comparison: any randomized trial in people with or without cancer.	A systematic review searching to April 2015 found no randomized trial and no study of treatment (Fenton & Huang, 2016), and the searches for this page did not identify a trial since. There is no body of evidence to rate. Not rated is not a finding of no effect or of safety.
Death from any cause: the reported linear association per 10 milliequivalents a day higher potential renal acid load score (not a test of the diet)	Very low	GRADE, this page’s own judgment; the review published no certainty rating. Comparison: 6 prospective cohorts of general populations and clinical groups, with varying follow-up; the review’s reported pooled odds ratio 1.03, 95% confidence interval 1.01 to 1.05, per 10 milliequivalents a day (Hajizadeh-Sharafabad et al., 2026). The question is whether the reported linear association is smaller than a 10% relative increase per 10 milliequivalents a day (a ratio of 1.10), a threshold that is this page’s analytical convention, not a validated patient-important threshold.	Observational studies start at low. Lowered 1 level for serious risk of bias: diet was measured once at baseline with memory-based methods, and residual confounding is likely. That gives very low, the floor; the further concerns below are recorded but cannot lower it further. Inconsistency: the populations and exposure shapes differed, some original relationships were U-shaped, and heterogeneity was moderate (I squared 48.4%); this page does not claim a common causal dose-response relation. Not lowered for indirectness: the row names the mixed cohorts that were studied. Imprecision: the interval of 1.01 to 1.05 excludes the 1.10 convention for the linear pooled estimate. Publication bias cannot be assessed with 6 studies, although the review’s test was not significant. The review calls the pooled measure an odds ratio although its methods describe included hazard ratios; this page uses the review’s term. The other score, net endogenous acid production (1.00, 0.96 to 1.05), is a separate result and is not combined. Low minus 1 gives very low. A relative ratio does not give a common absolute risk across these populations, and an association with a score does not show that the alkaline diet changes the risk of death.

How this archive talks about weight. This page reports what studies measured, including body weight, and does not treat weight change as a goal or as a measure of a diet’s success. Weight a person loses without meaning to can be a sign of a health problem, and where it is, the page names it as a reason to see a clinician. People are described the way the study described them.

Last reviewed: Reviewed and approved by James Peth, MS, MPH, PhD, on November 14, 2026, after a combined final review of the sixth batch of 5 archive pages, the repairs it asked for and a targeted recheck. Written November 8, 2026, from work begun October 21, 2026; company pages and prices were checked November 8, 2026.

What changed: Revised after the combined final review. The blood-pH row and the banner are no longer graded against a threshold; the urine-pH row is low and provisional; the mortality row is now rated very low as a reported association; the credibility classes were confirmed from the full review; the bone trials are described as not detecting a clear between-group difference; the U.S. Federal Trade Commission’s 2021 letter to Enagic USA was added; and the low blood sugar sequence was added to the referral boundaries. The GRADE judgments in the table are this page’s own. Some sources could be read only as abstracts, and the page says so where each is used; none of them carries a GRADE rating.

Next scheduled review: November 2027. Pages built on annual guidance are rechecked each year. The company pages and federal pages cited here change from time to time and should be rechecked first.

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Diet Reference Archive | One James

Prepared by James Peth, MS, MPH, PhD

© 2026–2027 One James. All rights reserved.

This page is for education and coaching practice. It is not medical or dietary advice.