by American Institute for Cancer

The claim: Acidic foods can alter the body’s pH balance and promote cancer.

The facts: Several concerned readers have written to AICR in recent weeks confused about online claims that acidic foods may increase cancer risk. It’s time to set the record straight.

The unsubstantiated theory is based on lab studies that suggest cancer cells thrive in an acidic (low pH) environment, but cannot survive in alkaline (high pH) surroundings. While these findings are accurate, they apply only to cells in an isolated lab setting. Altering the cell environment of the human body to create a less-acidic, less-cancer-friendly environment is virtually impossible.

While proponents of this myth argue that avoiding certain foods and eating others can change the body’s pH level, these claims stand in stark contrast to everything we know about the chemistry of the human body. Acid-base balance is tightly regulated by several mechanisms, among them kidney and respiratory functions. Even slight changes to your body’s pH are life-threatening events. Patients with kidney disease and pulmonary dysfunction, for example, often rely on dialysis machines and mechanical ventilators (respectively) to avoid even small disruption of acid-base balance.

Lastly, home “test kits,” which measure the pH of urine, do not relay information about the body’s pH level. True, foods, drinks and supplements will affect the acidity or alkalinity of urine, but it is the only fluid that is affected. In fact, excess acid or base is excreted in the urine to help maintain proper pH balance in the body.

The take-away: What you eat can have a profound affect on your cancer risk, but the acidity or alkalinity of foods is not important. Instead, focus on making dietary choices that can truly affect your risk: Eat a wide variety of vegetables, fruits, whole grains and beans; Limit consumption of red and processed meats; Enjoy alcohol in moderation, if at all.