Green circle with question mark inside Most likely or definitely true

Red circle with X insideFalse/misinformation

Gray circle with question mark insideWe’re not sure yet

Change or refine your search

A very acidic diet increases cancer risk

What you may have heard

Given that cancer cells grow well in an acidic environment, many people have questioned whether a diet high in acidic foods can increase your risk of cancer.

What the science tells us

In chemistry, the pH scale is a measure for how acidic or basic a solution is. The pH scale ranges from 0-14: 7 is neutral, less than 7 is acidic and greater than 7 is basic.

Epidemiological Evidence

There are no human epidemiological studies that have studied the relationship between pH and cancer. 

Laboratory Evidence/Supporting Evidence

There is no laboratory evidence that acidic pH increases risk for cancer. While it is true that cancer cells grow well in an acidic environment, your body’s pH levels are not determined by the food you eat (MD Anderson). Factors that determine your body’s pH include fluid loss, electrolyte levels, and organ function.

IARC Carcinogen Classification: Not Classified

How to reduce your risk

Research shows that there is not one diet or one food that can prevent cancer. However, a balanced diet and getting enough physical activity can prevent excess weight gain, which is associated with cancer risk. To prevent weight gain, 150-300 minutes of moderate-intensity activity per week is recommended  (Mayo Clinic). A healthy diet includes low-calorie and nutrient-dense foods (such as fruits, vegetables, and whole grains), avoids saturated fat, and limits sweets and alcohol. Identifying situations that trigger overeating and having tools to address these situations can also help in preventing weight gain. Finally, consistency in diet and exercise and monitoring your weight regularly can help keep off excess pounds.

Bottom line

Your blood pH is not affected by your diet, and there is no one diet to prevent cancer. Instead, focus on eating a balanced diet and exercising regularly.

MD Anderson: Alkaline diet
American Institute for Cancer Research: Alkaline diet
Mayo Clinic: Obesity


Published: July 7, 2021
Verified/updated: August 22, 2022