Alkaline Diet 101: Review, Research, Food List, and More
By Moira Lawler
Medically Reviewed by Lynn Grieger, RDN, CDCES
The alkaline diet, also called the alkaline ash diet or alkaline acid diet, was made popular by its celebrity followers. Big names like Victoria Beckham, Jennifer Aniston, and Kate Hudson have said they tried the diet with positive results.
In 2013, Victoria Beckham tweeted that the alkaline cookbook Honestly Healthy: Eat With Your Body in Mind, the Alkaline Way, written by the vegetarian chef Natasha Corrett and the nutritionist Vicki Edgson, was her favorite. Since then, the alkaline diet has become much more common.
But diets that work for celebrities aren’t necessarily meant to work for everyone or to yield long-term results.
“I don’t know Victoria Beckham, but to look at her, she has to be following a low-calorie diet — which might work for her,” says Natalie B. Allen, RD, a clinical assistant professor of biomedical sciences at Missouri State University in Springfield.
Allen says it’s crucial to remember that celebrities may have people shopping for them, making their food, and going to the farmers market and the grocery store — commitments that may not be practical for the rest of us when we go on a restrictive diet.
Not to mention, experts say, there’s a lack of research behind the main principles of the alkaline diet — and for some people, the approach may come with health risks.
What Is the Alkaline Diet Exactly?
Though there is no research to support these claims, the premise of the alkaline diet is that the foods you eat can change your body’s pH. Promoters of the diet believe that by eating foods that are less acidic and more alkaline, you’ll be protected from several health issues.
The diet centers on the unproven acid-ash hypothesis, which essentially says consuming a diet rich in fruits and vegetables and with moderate amounts of protein promotes an alkaline load and a healthier lifestyle. (1)
The alkaline diet emphasizes consuming alkaline foods in an attempt to make the body’s pH more alkaline. That said, it is impossible to change the body’s pH through diet. Indeed, the body’s pH actually varies based on the region. For example, the stomach is more acidic. (More on this later.)
In any case, the measure of pH tells you how acidic or alkaline something is and ranges from 0 to 14.
pH Levels in the Body
- 0 is extremely acidic
- 7 is neutral
- 14 is very alkaline
Alkaline Diet Food List: What to Eat and Avoid
The diet is organized around the pH of individual foods. Some versions are less strict, meaning they may allow grains for their health benefits despite their slightly acidic pH. But generally, if you’re following the alkaline diet, you’ll want to follow the food list below, steering clear of the acidic foods, limiting or avoiding the neutral foods, and focusing on the alkaline foods. (2)
Acidic Foods to Avoid
- Meat (especially corned beef, canned lunch meat, turkey, veal, and lean beef)
- Cottage cheese
- Cheese (especially Parmesan cheese, reduced-fat cheddar, and hard cheeses)
- Ice cream
- Eggs (the egg yolk in particular)
- Grains (brown rice, rolled oats, spaghetti, cornflakes, white rice, rye bread, whole-wheat bread)
- Peanuts and walnuts
- Other packaged, processed food
Neutral Foods to Limit
- Natural fats such as olive oil, cream, butter, and milk
Alkaline Foods to Eat
- Unsweetened fruit juices
- Black currants
- Vegetables (especially spinach)
- Mineral soda water
- Soy food
There isn’t a specific meal plan guide, either. You can follow recipes online or from alkaline diet cookbooks, or simply use the list of alkaline foods to create your own dishes.
Is This How Our Ancestors Ate?
The alkaline diet’s emphasis on fruit and vegetables over processed foods overlaps considerably with the paleo diet, which is meant to mimic the dietary habits of our hunter-and-gatherer ancestors. But research doesn’t necessarily support the idea that our early ancestors consumed alkaline diets. According to previous research, about one-half of the 229 historical diets researchers of the paper looked at were acid-producing, while the other half were alkaline-forming. (3)
Another past study found the disparity may be location-based. The researchers found that the farther away from the equator that people lived, the more acidic their diets were. Because ancestors of Homo sapiens lived in East Africa, which is closer to the equator, they were likely following alkaline diets. (4)
More on What Studies Suggest About Food and pH
The kidneys and lungs are largely responsible for maintaining a balanced pH in the body, and it’s very tightly regulated. Blood pH ranges from 7.2 to 7.45, says Jennifer Fitzgibbon, RDN, a registered oncology dietitian at Stony Brook University Cancer Center in New York. The kidneys also help balance pH levels in urine, according to UC San Diego Health. (5) A urine pH of 4 is considered strongly acidic, while 7 is neutral and 9 is strongly alkaline, notes Michigan Medicine. (6)
But here’s the tricky part: A style of eating can’t change your body’s pH. You may notice a difference in your urine pH, which can be measured with a simple dipstick test (also called a urine test strip), but that won’t tell you your overall levels because urine pH doesn’t reflect your body’s pH, according to MedlinePlus. (7) That’s because excess acid might be excreted through the urine in order to balance the body’s pH levels, notes the American Institute for Cancer Research. (8)
If your body’s pH changes, it’s because of a serious health issue. Urine with a high pH could indicate a urinary tract infection (UTI) or kidney stones, while a low pH could signify diarrhea, starvation, or diabetic ketoacidosis. (7,9)
Can the Alkaline Diet Result in Weight Loss, a Reduced Risk of Cancer, and Other Benefits?
Advocates of the alkaline diet make some bold claims. The primary focus of the eating approach isn’t weight loss — although that’s a likely result given the restrictions — but instead disease prevention and treatment. Followers and authors of the many guides and recipe books say the alkaline diet can treat diseases and chronic conditions, including cancer and kidney disease.
From a scientific perspective, these claims aren’t realistic, says Adrienne Youdim, MD, an associate professor of medicine at the UCLA David Geffen School of Medicine in Los Angeles. But, she says, the foods listed as alkaline tend to be healthy, and when you look at eating approaches like the widely studied and beneficial Mediterranean diet, you can reasonably say the focus on these foods is a healthy approach. Among other benefits, a review published in March 2014 in the International Journal of Cancer suggested following a Mediterranean eating style may reduce your risk of cancer. (10)
Still, despite the alkaline diet having been widely studied, there aren’t any definitive studies suggesting that this approach can have an effect on cancer — one of the biggest draws of the diet. Fitzgibbon says the cancer treatment theory is based on the claim that cancer cells thrive in an acidic environment. And while this is true in a lab setting, it’s nearly impossible to alter a cell environment to create a less acidic environment in our bodies, she says.
There was one preliminary study published in April 2019 in the International Journal of Cancer that found alkaline diets may offer a protective factor against breast cancer, but most of the research has been inconclusive. Most results, however, do point to one dietary measure that may reduce breast cancer risk: eating less meat, and more fruits and veggies, researchers reported. (11)
The American Institute for Cancer Research does not support claims about cancer and the alkaline diet, saying the acidity or alkalinity of a food isn’t important when it comes to human body chemistry. (9) Eating a largely plant-based diet with lots of fruits, vegetables, and whole grains without worrying about alkalinity is a healthy approach that can help lower your risk for cancer and chronic diseases. (9) So the alkaline diet might be a good approach for people fighting cancer, but not for the reasons given by fans of the diet, according to a study published in November 2018 in Oncology. (12)
On the other hand, an earlier review, published in the Journal of Environmental and Public Health, found that eating more alkaline foods, such as fruits and veggies, may help reduce your risk of hypertension and stroke, as well as improve memory and cognition. (2) It could help preserve muscle mass, too. A past study found following a more alkaline diet was positively associated with higher muscle mass indexes in women, likely because fruits and vegetables have potassium and magnesium, which help maintain muscle. (13)
People with chronic kidney disease may also benefit from focusing on alkaline foods because too much protein is hard on the kidneys. In an article published in May 2017 in the Journal of Renal Nutrition, the author argued that by reducing acid load to the kidneys through a low-protein diet with an emphasis on plant proteins you may be able to slow kidney disease progression and improve your kidney function. (14) A study published in July 2018 in the Iranian Journal of Kidney Diseases noted an alkaline diet slows down the rate at which the kidneys’ blood-filtering systems declines. (15)
There are also claims that the alkaline diet can reduce the risk of osteoporosis. The theory is referred to as “acid-ash hypothesis of osteoporosis” and states eating an acid-rich diet, like the Western diet, can erode the bones and lead to osteoporosis by increasing calcium in urine and reducing calcium present in the body, according to a previous study. (16) But the theory doesn’t hold up.
Researchers of a September 2014 study published in Journal of Bone and Mineral Metabolism noted that it seems acid-producing diets plus low calcium intake could lead to bone issues, but if calcium levels are high, eating an acidic diet might even be protective. (17) A prior review and meta-analysis concluded that there’s no evidence that an acidic diet can lead to bone disease, and there’s no evidence it can protect bones either. (18)
Who Is the Alkaline Diet Best For?
A more relaxed version of the alkaline diet that doesn’t strictly eliminate healthy nuts and grains can be beneficial for overall health. Fundamentally, a plant-based diet can be good for lowering your risk of many cancers, heart disease, type 2 diabetes, and stroke, notes the American Heart Association. (19) For those with a history of kidney stones or kidney disease, a plant-based diet — but not necessarily an alkaline diet — may help, according to an article published in January 2019 in the Clinical Journal of American Society of Nephrology. (20)
Who Should Avoid the Alkaline Diet?
For people without preexisting health conditions, the alkaline diet is generally safe, but some people may be left feeling hungry or may not get enough protein for their needs. In addition to restricting many unhealthy foods, some healthy foods are left out as well.
“Some of the acidic foods are quite healthy, like eggs and walnuts,” says Tracy Lockwood Beckerman, RD, the owner of the private nutrition practice Tracy Lockwood Nutrition in New York City. Eliminating these can cause people to become obsessive and stray away from nutrient-dense foods we need, she adds.
Although the focus is on healthy plant-based foods, the alkaline diet is not designed for weight loss, and there are no guides for portion control or fitness routines, which the Centers for Disease Control and Prevention recommends for disease prevention. (21) Also, if you aren’t sure how to get enough protein using plant sources, you could be left feeling very hungry.
What Else to Know Before Trying the Alkaline Diet
In any case, you should talk with your healthcare team before trying the alkaline diet. Because the eating approach can be restrictive, you want to make sure you’re not cutting out important nutrients or unintentionally harming your health.
Additional reporting by Rena Goldman.