A “Basic” Examination of the Alkaline Diet

The web is once again abuzz with suspicious claims about the alkaline diet. A staple of some alternative medicine circles for years now, this eating plan isn’t new to the pantheon of internet health-woo.  Practitioners of this food fad claim that it can help prevent many ailments, including cancer, by regulating your internal pH.

Sound suspicious yet? You don’t need a PhD in chemistry for this diet to raise some major red flags. A quick examination of the science, and a few simple facts about the human body, show that this diet is… pretty basic.

What is an alkaline diet?

Some compounds produced through digestion are acidic while other compounds are basic (alkaline). As a quick chemistry primer: Acids and bases are measured on the pH scale. On the pH scale, 0-7 represents an acidic compound, while 7-14 represents a basic compound. Alkaline diet proponents claim that alkaline compounds (7-14 on the pH scale) are good for the body, and that a build-up of acidic compounds (0-7 on the pH scale) could lead to negative health effects. The main goal of the alkaline diet is to increase the amount of “alkaline foods” you eat and decrease the rest.

Which foods are included (and excluded)?

Many foods that are staples of a healthy eating pattern are actually included in the alkaline diet. Fruits, vegetables and nuts are all included as “alkaline foods.” Plant-based proteins from beans and soy products are also heavily encouraged on an alkaline diet. Unfortunately, that is where the good recommendations stop. The alkaline diet encourages adherents to (unnecessarily) restrict dairy, eggs, meats and cheeses. Besides the fact that these foods definitely don’t affect the pH of your blood (more on that later), the 2015 Dietary Guidelines for Americans show that they are important parts of a healthy eating style and can supply lean protein and micronutrients. So, when it comes to excluding foods from your diet, these so-called “acidic foods” shouldn’t be on the chopping block.

Health claims of the alkaline diet

According to alkaline dieters, “acid forming foods” cause a buildup of acidic compounds in body tissues and the bloodstream, which causes several adverse health conditions. Proponents of the diet claim that acid producing foods cause the breakdown of bone tissue, increase the risk for types of cancer, and  are risk factors for conditions such as heart disease and diabetes. Yikes. But rest-assured that there is some much needed science-based perspective coming your way.

Debunking the alkaline diet

It’s true that the digestion of foods creates acidic and basic chemical compounds. But, after that, the science behind the alkaline diet gets really shaky. Let’s debunk the alkaline diet with three short, science-based factoids:

  • Acidic and alkaline compounds from food have little or no effect on blood pH. Blood actually has its own built-in buffer system, to keep your internal pH just right. As long as you don’t have any serious conditions (like kidney disease or electrolyte deficiencies), you can safely assume that the pH balance of your body is on autopilot.
  • Yes, some foods can change the pH of urine. That doesn’t mean that the food is changing the pH of your bloodstream or causing any negative health effects. Only individuals with severe chronic conditions, such as kidney disease, can expect these slight changes in the pH of the urine to be linked to any potential health effects.
  • For anyone with healthy kidneys, acidic compounds in the blood have no effect on bone density or bone health. This claim has been thoroughly debunked.

There you have it. The foods you eat have very little, if any, effect on the pH of your body. Eating alkaline foods with the hope of regulating your body’s pH, or achieving long-term health benefits, will only lead to disappointment. Your best bet is to eat alkaline foods (like fruits, veggies, plant-based proteins) not because of the pH of their byproducts, but because they are important components of a healthy eating style. 

This blog post includes contributions from Adam Sachs, a dietetic intern at the University of Maryland.

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