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Health & Disease

A Scientific Review of The Alkaline Diet – Fact or Fiction

alkaline
Green smoothie alkaline diet drink beside a wooden tray with alkaline diet vegetables and fruits: Banana, kiwi, spinach, lemon, cucumber, parsley , silver beat and garlic.

The alkaline diet is a new and popular trend in the fitness and dieting world, but what does the science of the Alkaline diet have to say?

The proposition underlying the consumption of low acidity foods is that they can adjust blood acidity and make your body more alkaline.

By becoming more alkaline, the supporters of this way of eating propose it will help prevent disease states such as osteoporosis, inflammation and even cancers – but does the research agree or is just another fad diet without scientific evidence?

In this article, I’ll discuss the science of the alkaline diet to see if it actually provides some unique benefits.

A Background on the Alkaline Diet

The alkaline diet is a style of eating which was influenced by the idea that the food you eat will enable the blood to have a higher pH and thus achieve a more alkaline, rather than acidic, state.

The allure of this style of eating and its theoretical change in blood pH (or level of acidity) is that many diseases, such as cancer, thrive in acidic environments.

It is also thought that by changing blood pH via food intake, you may also reduce the likelihood of osteoporosis, a degenerative bone disease that causes bones to become weak and fragile.

As such, proponents of the alkaline diet propose that eating alkaline foods, and thereby rendering blood more alkaline, reduces the likelihood of contracting diseases that are acidic in nature.

The Guidelines or Rules of an Alkaline Diet

The alkaline diet is a fairly restrictive diet in that you’ll need to avoid foods that have a low pH or are acidic in nature.

While participating in the alkaline diet, you’ll need to base your food consumption on how the food you consume ranks on the pH scale of acidity and alkalinity.

The pH scale ranks from 0 – 14, with 0 being most acidic and 14 being most alkaline.

  • 0 – 6: Acidic
  • 7: Neutral
  • 8 – 14: Alkaline

Throughout participation in the alkaline diet, your primary focus is avoidance of foods falling below number 7 on the pH scale, while placing emphasis on foods that rank above it.

As a general rule of thumb, certain foods are considered to be acidic due to the amount of acid that is excreted through urination after consumption (1).

  • Acidic: Dairy, meats, grains, alcohol and even caffeine
  • Neutral: Fats, egg whites, and water
  • Alkaline: Most vegetables, fruits and some nuts

In essence, eating foods that rank high on the scale of being alkaline will equate to eating a largely vegetarian, if not vegan, style of diet. If you’ve followed my work, you may already notice that this, (foods such as meat being classed as acidic and so off limits), could be a key issue. You’ll know I’m a big advocate of meats and fish, along with a high protein diet, so this major issue is discussed below.

Understanding How Your Blood Ph Functions

The human body has many different barriers and systems to avoid drastic change.

Since the body is a closed system, it is able to tightly regulate processes and adjust to any change in order to maintain homeostasis or regular conditions.

Unfortunately for proponents of the alkaline diet, blood pH is one of the most tightly regulated systems in the body (2).

Within the body, blood pH is interestingly already slightly alkaline having a blood pH in the range of 7.35 and 7.4 (3).

Any deviation from that range of pH can have very negative side effects and potentially even death.

When blood pH is too acidic, this is a condition called acidosis in which the lungs and kidneys are not able to regulate or eliminate acid in the blood, resulting in a decrease in your blood pH.

When blood acidity increases further outside the normal range, this can result in many different effects:

  • Headaches
  • Fatigue
  • Shortness of breath
  • Confusion
  • Kidney failure (4)

On the other side of the equation, metabolic alkalosis or the increase in blood pH, is a condition in which too much bicarbonate, a substance that reduces acidity in the blood, is created.

Side effects of alkalosis can include:

  • Confusion
  • Nausea
  • Vomiting
  • Muscle spasms (5)

Fortunately for humans, yet unfortunately for proponents of the alkaline diet, blood pH or relative acidity is tightly regulated to help avoid the symptoms of either acidosis or alkalosis.

In other words, your diet can change these ranges. If you fall out of these ranges because of an illness or disease, you will be very ill and may even die. So, on its own, this one issue basically debunks the whole principle behind the Alkaline diet.

Debunking The Alkaline Diet For Disease

Considering that blood pH is tightly regulated, it is very unlikely that simply consuming alkaline-based foods will directly raise or lower its acidity (6).

Additionally, there is little evidence that specifically abstaining from eating foods with a relatively high acidity will prevent or treat ailments such as osteoporosis or cancer – two of the most popular reasons for beginning the diet.

Most cancerous tumors undergo a process called anaerobic fermentation, in which cells metabolize glucose through a process called glycolysis. It is theorized that this is due to dysfunction of mitochondria. Mitochondria are organelles that use oxygen to produce energy.

In doing so, this process results in the buildup of lactate, an acidic substance that is a byproduct of glycolysis.

As it turns out, this production of acidic lactate is likely a result of the dysfunctional mitochondria, not because the environment is acidic. This is further rationalized by the fact that people with and without cancerous tumors exhibit a similar range of blood pH (7).

On the side of osteoporosis, many proponents claim that in order to maintain a stable blood pH as a result of increased acidity, calcium must be taken from bone, to help reduce acidity of the blood.

Over time, it is postulated that bone becomes depleted and eventually leads to disease states such as osteoporosis.

Unfortunately, this claim is largely unfounded. Additionally, it is actually primarily the function of bicarbonate, which is produced from the kidneys, that works to help reduce the acidity of the blood (2).

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So Can An Alkaline Diet Help With Health Or Disease?

No, but (indirectly) also yes …

While exclusively consuming foods that are alkaline based may not affect blood pH and thus benefit health or disease, I will say that eating a diet focused primarily on fruits and vegetables may be advantageous for overall health and disease prevention (but this is not linked to alkalinity).

In fact, the American Dietetic Association’s official stance on vegetable-based diets is that current research suggests they may be associated with reduced risk of different diseases such as heart disease, high blood pressure and type 2 diabetes (8).

Other research into paleo diets, fruit and vegetable intake and even vegan diets also supports the increased intake of these foods as beneficial for health and disease prevention. I think that’s one of the few nutrition rules that almost everyone actually agrees on, (well, maybe 99% of people at least).

Of course, there are also downsides too, especially if you want to optimize health, workout, exercise or want to maintain or add muscle mass. Of course, the biggest one is that eliminating meat, which has a bunch of health benefits, also removes the main protein source which is key for anyone who exercises.

In short, there’s no denying that increasing fruit and vegetable consumption may have beneficial effects. However, those benefits are simply due to an increase in consumption of beneficial nutrients and nothing to do with some magical alkalizing diet, juice or potion (sorry).

Rather than going Alkaline and cutting out key food groups such as meat, the best diet is one that is high in fruits/vegetables AND meat/fish but that still focuses on reducing processed food to achieve a well-balanced and healthy level.

Summary

The alkaline diet is a style of eating that focuses on consuming foods that are alkaline in nature while avoiding acidic foods.

Proponents of the diet claim that eating in this manner can reduce the acidity of your blood and result in prevention of diseases such as osteoporosis and cancer.

Unfortunately for proponents of the diet, blood pH is a tightly regulated process, which is only minimally affected by food consumption. Further, diseases such as osteoporosis and cancer are a result of factors other than acidity of the blood.

While the alkaline diet may not be effective in reducing blood acidity, maintaining a diet with an emphasis on vegetables and fruit may be advantageous for health and prevention of a wide range of diseases.

In short, the alkaline diet is fundamentally flawed and anyone with a basic scientific understanding will confirm this. With that being said, eliminating some processed foods and focusing on more fruit and vegetables is never a bad thing… just don’t be tricked into following another health fad

References

1. 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.

2. Koeppen, B. M. (2009). The kidney and acid-base regulation. Advances in physiology education, 33(4), 275-281.

3. Schwalfenberg, G. K. (2011). The alkaline diet: is there evidence that an alkaline pH diet benefits health?. Journal of Environmental and Public Health, 2012.

4. Acidosis. (n.d.). Retrieved April 24, 2017, from http://www.umm.edu/health/medical/ency/articles/acidosis

5. Alkalosis. (n.d.). Retrieved April 24, 2017, from http://www.umm.edu/health/medical/ency/articles/alkalosis

6. Bonjour, J. P. (2013). Nutritional disturbance in acid–base balance and osteoporosis: a hypothesis that disregards the essential homeostatic role of the kidney. British Journal of Nutrition, 110(07), 1168-1177.

7. Vander Heiden, M. G., Cantley, L. C., & Thompson, C. B. (2009). Understanding the Warburg effect: the metabolic requirements of cell proliferation. science, 324(5930), 1029-1033.

8. Craig, W. J., & Mangels, A. R. (2009). Position of the American Dietetic Association: vegetarian diets. Journal of the American Dietetic Association, 109(7), 1266-128

About the author

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Rudy Mawer, MSc, CISSN

Rudy has a 1st class BSc in Exercise, Nutrition & Health and a Masters in Exercise & Nutrition Science from the University of Tampa. Rudy currently works as a Human Performance Researcher, Sports Nutritionist and Physique Coach. Over 7 years he has helped over 500 people around the world achieve long last physique transformations.

He now works closely with a variety of professional athletes and teams, including the NBA, USA Athletics, World Triathlon Gold Medalists, Hollywood Celebrities and IFBB Pro Bodybuilders. If you would like to get in contact or work with Rudy please contact him on social media.

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