Alex Zawilski, MS, RD, is a clinical dietitian with Sharp Chula Vista Medical Center. She separates fact from fiction when it comes to the diet and its effectiveness.
What is the concept behind the alkaline diet?
The alkaline diet is based on pH. The pH scale ranges from 0 to 14, with a pH of 7 being neutral. A pH of less than 7 indicates acidity, and a pH of greater than 7 indicates alkalinity.
“The theory behind the alkaline diet is that acid-producing foods will lead to a metabolic imbalance,” says Zawilski. “The diet claims that eating more alkaline-forming foods and fewer acid-forming foods will help reduce inflammation and increase resistance to disease.”
Alkaline-forming foods are thought to be mostly fruits and vegetables, including:
- Dairy products
According to Zawilski, the answer is, not directly.
“There is not sufficient evidence to support that foods that may have ‘acid-forming’ or ‘alkaline-forming’ effects have any impact on your health,” she says. “However, because this diet does encourage higher intake of fruits and vegetables, and decreases intake of processed foods, sugar and alcohol, it is possible that it may promote weight loss.”
The fact that many alkaline foods are plant-based also contributes to why some think the diet is beneficial. “Following a diet that is high in antioxidant-rich fruits and vegetables may in itself also help to reduce risk for many chronic diseases,” says Zawilski.
Are there any negative health consequences of following the alkaline diet?
Aside from the fact that the touted benefits may not live up to the hype, the diet could have some unintentional negative side effects.
“The alkaline diet strictly limits important healthy foods such as dairy, poultry, fish and whole grains, which can result in some nutrient deficiencies and make it difficult to maintain long term,” says Zawilski.
What about products advertised as alkaline-forming, such as alkaline water?
Alkaline water has a pH of above 7, whereas typical tap or bottled water in the United States ranges anywhere from 5.2 to 9.5.
“The proponents of alkaline water suggest that it helps to neutralize acid in the blood, maintains your pH, increases energy, improves memory and assists in hydration” says Zawilski.
She says it is unlikely that alkaline water has health benefits beyond hydration.
“If you drink alkaline water, the hydrochloric acid in your stomach will neutralize any alkaline properties that water might have. By the time the water gets around to affecting the blood, the pH has already been altered several times by the digestive tract,” she says.
Zawilski also points out that blood pH is not something that can be altered easily. “No food will alter your blood pH, as this is something that your body strictly maintains. The lungs and the kidneys work diligently to keep blood pH tightly controlled around 7.4. Consequences of blood pH changes would be life-threatening,” she says.
While there may not be research to support the alkaline diet’s effectiveness, there are some key lessons we can take away from it.
“Instead of focusing on the acid- or alkaline-forming effects of foods, focus on consuming a diet high in fresh fruits and vegetables, whole grains, lean animal protein, plant protein and low-fat dairy products,” says Zawilski.