High-Carb Diet, Bigger Prostate Tumor?

Diet Rich in Carbohydrates May Increase Prostate Cancer Size, Lab Tests Show

Medically Reviewed by Louise Chang, MD on November 27, 2007

Nov. 27, 2007 -- New research links a high-carbohydrate diet to bigger prostate cancers.

Canadian scientists reported that news today in the Journal of the National Cancer Institute.

The findings are based on lab tests in mice. But the researchers argue that their findings hint at possible benefits for men with prostate cancer.

In the study, scientists injected human prostate cancer cells into 40 male mice and split the mice into two groups:

  • High-carbohydrate diet loaded with the sugars dextrin and sucrose
  • Low-carbohydrate diet

Both diets were high in fat and provided the same number of calories by cutting protein on the high-carb diet.

The mice kept their assigned diets for nine weeks. By the end of the study, the mice on the high-carb diet had prostate tumors that were 45% bigger than the mice on the low-carb diet.

The mice on the high-carb diet also gained 15% more weight than the mice on the low-carb diet.

That extra weight gain came with higher blood levels of insulin (a hormone that controls blood sugar) and insulin-like growth factor 1 (a protein that spurs cell growth).

The findings support the idea that diets that reduce insulin level "may have benefits for prostate cancer patients," especially those with high insulin levels, write the researchers.

They included Vasundara Venkateswaran, PhD, of the urology division at Toronto's Sunnybrook Health Sciences Centre.

But more research is needed to confirm that theory. For instance, Venkateswaran's team doesn't know what effect protein consumption had on the mice's tumors.

Earlier this month, other researchers reported that a no-carbohydrate diet might slow prostate cancer growth -- at least in mice.

But people eat differently from mice, and none of the researchers is telling people to nix carbohydrates.

Carbohydrates come in many forms, including vegetables, fruits, and whole grains -- foods that are staples of a healthy diet. The mouse studies -- which didn't track long-term effects -- don't change those guidelines.

Show Sources

SOURCES: Venkateswaran, V. Journal of the National Cancer Institute, Dec. 5, 2007; vol 99: pp 1793-1800.WebMD Medical News: "No-Carb Diet May Curb Prostate Cancer." News release, Journal of the National Cancer Institute.

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