A new study in mice has suggested that restricting carbohydrates could slow the growth of prostate cancer tumours.
"Previous work here and elsewhere has shown that a diet light in carbohydrates could slow tumour growth, but the animals in those studies also lost weight, and because we know that weight loss can restrict the amount of energy feeding tumours, we weren't able to tell just how big an impact the pure carbohydrate restriction was having, until now," said Stephen Freedland, M.D., a urologist in the Duke Prostate Center and lead investigator on this study.
Freedland said that 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 tumour growth.
For the study, 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. They were then injected with prostate tumours at the same time.
"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 tumour growth delay," he said.
The findings appear in the May 26, 2009 online edition of the journal Cancer Prevention Research.