The Alkaline Diet (also referred to as the Acid-Base Diet) is often marketed to the public as a way to reduce the risk of developing cancer. The concept behind this marketing suggests that eating certain foods such as dairy, meat and grain products, produces waste products which cause the body to become “too acidic,” leading to an environment where cancer thrives. Fans of the diet say that reducing intake of these foods can change the body’s pH, meaning the chances of developing cancer is reduced. Is there any evidence to support these claims?
To understand the claims, we must first look at the science behind pH.
The pH Scale
The pH scale ranges from 0 to 14, and is used to identify if a liquid is acidic or alkaline in nature. Acidic liquids have a low pH, whereas alkaline liquids have a high pH. Neutral pH is set at pH 7.
Waste products from the breakdown of foods can also be classified as being acidic or alkaline. Foods which produce acidic waste products include animal products, complex carbohydrates and alcohol. Fruits and vegetables create waste products which are alkaline.
Cancer and pH
Some studies conducted in laboratories have shown that cancer cells grow quicker in an environment that is more acidic in nature. For this reason, fans of the alkaline diet believe that avoiding food which produce acidic waste products may help to reduce the acidity in the body, meaning it is less likely that cancer cells will thrive.
The pH level of bodily fluid is not equal. The bloods normal pH is slightly alkaline, ranging between 7.35 and 7.45. This pH is tightly regulated by the body, and any changes outside this pH are treated as a medical emergency.
Stomach acid is very acidic, at pH 3. Stomach acid mixes with all foods consumed, helping to break them down. This mixture then moves along the rest of the digestive system, where it is made more alkaline due to the addition of digestive enzymes. The effect of these enzymes means that the pH of waste products of food is irrelevant, as the digestive enzymes will adjust the overall pH to be alkaline.
There is no evidence to suggest that the acidity or alkalinity of foods can change the body’s pH. Instead, focus on making lifestyle choices which have been shown to reduce the risk of developing cancer: eat a well-balanced diet, limit intake of red and processed meats; enjoy alcohol in moderation and participate in regular physical activity.