Calorie Restriction Slows Spread of Triple-Negative Breast Cancer

A plethora of books, blogs, and infomercials offer "cures" for cancer, often in the form of special diets. While some of these plans are based in science, many are not—and the worst of them are merely money-grabbing schemes. So with all the misinformation out there, the legitimate discovery of a cancer-busting diet is very exciting.

A recent study conducted at Thomas Jefferson University in Philadelphia shows that calorie restriction can decrease chances for metastases in patients with triple-negative breast cancer, one of the most aggressive forms of the disease. The study, published in Breast Cancer Research and Treatment, points to a simple and cost-effective treatment that, while commonly associated with weight loss, has major implications in cancer research.

Read More: Navigating Your Treatment When the Diagnosis Is Cancer »

How Does It Work?

Calorie restriction, or limiting food intake to a certain calorie percentage, has been shown to be effective in combating health issues related to weight and diet, such as obesity and diabetes. The same regulated decrease in calories has now been shown to diminish triple-negative breast cancer, in that the diet turns off some of the signals in the molecular pathways responsible for creating tumors. When coupled with radiation, the results of calorie restriction are extremely promising.

“More calories or obesity can cause tumors to initiate,” said senior author Nicole Simone, M.D., an associate professor in the department of Radiation Oncology at Thomas Jefferson University.

Simone and fellow researchers utilized this knowledge when designing the study, focusing on the relationship between maintaining a healthy weight and decreasing tumors.

Learn the Warning Signs of Breast Cancer »

”We figured because most of our patients are coming to us with tumors, they’re not coming to us on a diet,” Simone said. By instituting calorie restriction, ”we're inducing a stress on the patient, which is something they’re not used to.”

In the study, mice with triple-negative breast cancer were given 30 percent less than what they normally ate. The cancer cells in these mice with restricted calorie intake decreased production of certain microRNAs (non-coding RNAs that help regulate gene expression) that are often increased in triple-negative breast cancers that metastasize. The decrease in microRNA production also helps maintain the extracellular matrix, the part of the multicellular structure that provides support to surrounding cells. A strong matrix encases the tumor, making it harder for cancer cells to get out and attack other parts of the body.

Calorie Restriction for Other Cancers

As with many health issues, maintaining weight is crucial. Calorie restriction has potential in treating other kinds of cancers, and the results from this study could pave the way for other medical possibilities. Researchers envision a drug that mimics decrease of production of  the microRNAs associated with metastasis in triple-negative breast cancer, although the results might not be as successful as with real calorie restriction.

The results have a high chance of being similar in men with breast cancer, according to Simone, because many cases of male breast cancer are triple-negative. This particular study examined only female mice.

Check Out the Best Breast Cancer Blogs of 2014 »

Calorie Restriction for Everyone?

The results with mice showed promise, but the real test will be in calorie restriction for human participants. Simone is currently enrolling patients in the CaReFOR (Calorie Restriction for Oncology Research) trial, which will continue exploring the success of calorie-restricted diets in relation to cancer.

Of course, a healthy diet benefits all cancer patients, but restricting calories is not always appropriate. Simone does not recommend that someone diagnosed with cancer automatically begin a calorie-restriction regimen because many individual factors are at play for each patient.

The biggest takeaway may be that cancer treatments require a holistic approach to health, including diet and physical activity. “Everything in moderation,” Simone said. “Paying attention to what we're taking into our bodies can really affect outcome.”

Find Clinical Trials for Breast Cancer Treatments »