According to a study on prostate cancer modified mice, restricting carbohydrates, regardless of weight loss, appears to slow the growth of tumors in prostate cancer.

In the US alone there will be an estimated 192,280 new cases of prostate cancer in 2009, with an estimated 27,360 deaths from prostate cancer.

"Previous work here and elsewhere has shown that a diet light in carbohydrates could slow tumor growth, but the animals in those studies also lost weight, and because we know that weight loss can restrict the amount of energy feeding tumors, we weren't able to tell just how big an impact the pure carbohydrate restriction was having, until now," said Stephen Freedland, lead investigator on this study.

The researchers believe that insulin and insulin-like growth factor contribute to the growth and proliferation of prostate cancer, and that a diet devoid of carbohydrates lowers serum insulin levels in the bodies of the mice, thereby slowing tumor growth, Freedland said.

The prostate cancer modified mice were fed one of three diets: a very high fat/ no carbohydrate diet; a low-fat/ high carbohydrate diet; and a high fat/ moderate-carbohydrate diet, which is most similar to the "Western" diet most Americans eat, Freedland said.

"The mice that were fed a no-carbohydrate diet experienced a 40 to 50 percent prolonged survival over the other mice," Freedland said.

Mice on the no-carbohydrate diet consumed more calories in order to keep body weights consistent with mice on the other study arms.

"We found that carbohydrate restriction without energy restriction, or weight loss, does indeed result in tumor growth delay," he said.

The researchers plan to begin recruiting prostate cancer patients at two sites, Duke and the University of California, Los Angeles, for a clinical trial to determine if restricting carbohydrate intake in patients with prostate cancer can similarly slow tumor growth. The trial should begin within a few weeks.

"It's very exciting, this is a potential new mechanism to fight prostate cancer growth and help patients live longer with their disease," Freedland said.
References:
1. Stephen Freedland, et al. Duke University Medical Center.
2. National Cancer Institute.