Low-carbohydrate, high-protein diets help some people lose weight, but can they prevent cancer too? According to a study published in the journal Cancer Research, low-carb, high-protein diets may slow down tumor growth and help to ward off cancer, the third leading cause of death in the United States.
Low-Carbohydrate Diets and Cancer: Are They Protective?
To see what effect a high-carbohydrate diet would have on cancer growth, researchers implanted tumor cells into mice. Then they placed them on either a low-carbohydrate, high-protein diet or a typical American diet with a ratio of 55% carbohydrate, 23% protein and 22% fat. The low-carb mice ate a diet consisting of 15% carbohydrate, 58% protein and 26% fat. How did the mice fare? The researchers found that the tumor cells grew more slowly in mice that ate the low-carb, high-protein diet relative to the mice on the typical American diet.
They did a similar experiment on mice that were genetically bred to develop breast cancer. In this case, 70% of the mice on the typical American diet died from cancer, while less than 1 in 3 progressed to cancer on the low-carb, high-protein diet. Of course, it’s impossible to say whether these results hold true for humans too, but the researchers in this study believe these results should raise a red flag about the typical American diet and cancer risk.
How Might a Low-Carbohydrate Diet Prevent Cancer?
When you eat a high-carbohydrate diet, your body produces greater amounts of insulin to help transport the excess glucose into cells. Insulin and a close relative called insulin-like growth factor seem to fuel the growth of tumor cells by helping them grow and divide faster.
According to other research, high levels of insulin increase the risk of certain types of cancer including breast and colon cancer. People who are overweight are often insulin resistant and have higher levels of insulin in their bloodstream. This may explain why they are at greater risk of some forms of cancer.
Should You Go on a Low-Carbohydrate Diet to Prevent Cancer?
It’s too soon to recommend a low-carb diet, especially one that’s high in protein. Some studies have even linked high-protein diets with a greater risk of some forms of cancer. A better idea is to change the type of carbohydrates you eat. Instead of choosing processed foods and packaged foods that are high in sugar and low in fiber, eat more fruits, vegetables and whole grains. The fiber in these foods helps to stabilize blood sugar levels and reduce the amount of insulin your pancreas releases in response to a meal. Fruits and vegetables also contain antioxidants that help to protect cells against damage that can lead to cancer. This type of diet also helps with weight control, another factor that can influence cancer risk.
The Bottom Line?
Reducing processed foods and other “bad carbs” in your diet and replacing them with carbohydrate sources that are high in fiber and antioxidants could work in your favor when it comes to cancer risk. Kick the fast food and processed food habit and live healthier – and longer.
BMJ 321 : 847 doi: 10.1136/bmj.321.7265.847.
Medical News Today. “Low-Carbohydrate, High-Protein Diets May Reduce Both Tumor Growth Rates and Cancer Risk”
Washington Post. “High Protein Diets May Boost Cancer Risk”