The Alkaline Diet: Fab or Fad?
The alkaline diet, also known as the acid-alkaline diet, is widely touted in books and online. It’s based on the idea that the typical American diet raises acid levels in the body. This is said to cause a broad range of health problems, including osteoporosis, cancer, and high blood pressure. Advocates claim that by eating less acid-forming foods, you can lose weight and improve your overall health.
Not everyone agrees, however, and the alkaline diet has some vocal critics as well. So, what’s the real scoop? Here’s what science says about this controversial diet.
Understanding pH Values
The alkaline diet focuses on your body’s pH level. This is a measure of how acidic or alkaline something is, using a scale from zero to 14:
7.0 is neutral
Below 7.0 is an acid; the closer to zero, the more acidic the substance
Above 7.0 is an alkali (also known as a base); the closer to 14.0, the more alkaline the substance
Different parts of the body normally have different pH values. For example, blood is slightly alkaline (pH 7.4). But the fluid inside cells has a lower pH (6.0 to 7.2), and it’s very acidic inside the stomach (pH 1.4 to 3.5).
It’s a complex system. Fortunately, your body already has multiple ways of keeping everything on track. Your blood contains substances that resist any changes in its pH level. Your lungs also remove acid from your body through exhaled air. And your kidneys excrete acid in urine.
A Closer Look at the Claims
The alkaline diet restricts a long list of foods, which are thought to make the body more acidic. These foods include meat, poultry, fish, eggs, cheese, and wheat products. Specific versions of the diet may also exclude other foods, such peanuts, walnuts, corn, cranberries, plums, and sweets. In place of these foods, the diet emphasizes most fruits and vegetables, which are thought to keep the body more alkaline.
Following such a strict diet can be tough. Plus, the diet may not work well—at least, not for the reasons advertised. Research shows virtually no effect on blood pH levels, although a change in diet does alter the pH of urine.
One research review found no clear-cut evidence that the alkaline diet improves bone health. Another turned up only a single study that looked at the diet’s cancer-fighting potential, and that study didn’t show any benefit.
The Diet’s Secret Ingredient?
On the plus side, the alkaline diet is rich in fruits and vegetables. That in itself is beneficial. Fruits and veggies help manage your weight by filling you up with relatively few calories. They help control your blood pressure and may protect against some cancers. Plus, they contain vitamins and minerals that are good for your bones.
Whether you’re aiming to lose weight or enhance your health, eating fruits and vegetables can help you reach those goals. But following the alkaline diet with its long list of off-limits foods is harder than simply upping your fruit and veggie intake. So far, there’s no research showing that it’s worth the extra effort.