Intermittent calorie restriction may lower breast cancer risk

Kathleen Blanchard's picture
Calorie Restriction and Breast Cancer Risk

New research shows it may not be what we eat, but our eating patterns that can reduce chances of breast cancer. The study, published in Cancer Prevention Research, a journal of the American Association for Cancer Research, suggests that calorie restriction has benefits for reducing risk of breast cancer, but how that is accomplished might be more important.

According to mice studies, breast cancer tumors were nine percent with intermittent calorie restriction, compared to thirty five percent in mice habitually taking in fewer calories, and seventy one percent in mice that ate what they wanted. The mice studied were ten week old females at high risk for developing breast tumors.

The researchers measured changes of a growth factor (IGF-1) in relationship to the two calorie restriction methods – chronic and intermittent. They hoped to discover why intermittent calorie restriction was more effective for preventing breast tumor growth.


Michael Pollak, M.D, an editorial board member for Cancer Prevention Research, says the study "contributes to accumulating evidence that caloric restriction acts by altering hormone levels rather than by directly starving cancers of energy. In particular, lower levels of insulin are associated with reduced food intake, and this may be protective."

The researchers hope to find pharmaceutical agents that can provide the same benefits of calorie restriction. Dr. Pollak also adds that maintaining an ideal body weight may be important for cancer patients.

Pollak says, "There is reason for concern that the 'obesity epidemic' may lead to an increased prevalence of a hormonal profile associated with elevated cancer risk and/or an adverse cancer prognosis. Therefore, in addition to its well-known general health benefits, maintaining an ideal body weight is also important in the specific contexts of cancer prevention and improving the prognosis of cancer patients."

The findings that calorie restriction could prevent cancer should spark interest in further studies. Study author Margot P. Cleary, Ph.D., is a professor at the Hormel Institute, University of Minnesota says, "Humans frequently regain lost weight discouraging the application of calorie restriction protocols for disease prevention."

American Association for Cancer Research