Walnuts can reduce breast cancer risk

Walnut consumption may provide the body with essential omega-3 fatty acids, antioxidants and phytosterols that reduce the risk of breast cancer, according to a study presented at the American Association for Cancer Research 100th Annual Meeting 2009.

Elaine Hardman, Ph.D., associate professor of medicine at Marshall University School of Medicine, said that while her study was done with laboratory animals rather than humans, people should heed the recommendation to eat more walnuts.

"Walnuts are better than cookies, french fries or potato chips when you need a snack," said Hardman. "We know that a healthy diet overall prevents all manner of chronic diseases."

Hardman and colleagues studied mice that were fed a diet that they estimated was the human equivalent of two ounces of walnuts per day. A separate group of mice were fed a control diet.

Standard testing showed that walnut consumption significantly decreased breast tumor incidence, the number of glands with a tumor and tumor size.

"These laboratory mice typically have 100 percent tumor incidence at five months; walnut consumption delayed those tumors by at least three weeks," said Hardman.

Molecular analysis showed that increased consumption of omega-3 fatty acids contributed to the decline in tumor incidence, but other parts of the walnut contributed as well.

"With dietary interventions you see multiple mechanisms when working with the whole food," said Hardman. "It is clear that walnuts contribute to a healthy diet that can reduce breast cancer."