Walnuts slow cancer growth, MU study finds
September 27, 2008
A Marshall University study has found that snack-size quantities of English walnuts appears to slow cancer growth in mice. Researcher W. Elaine Hardman of Marshall’s Joan C. Edwards School of Medicine set up the study to determine whether mice that ate walnuts had slower breast cancer growth than a group of mice that ate a more typical American diet.
“When we fed the mice the walnuts, the growth rate of the tumors they had was dramatically suppressed,” said Hardman, whose pilot study was published this month in the medical journal “Nutrition and Cancer.”
The study is believed to be the first to look at the effect of walnut consumption on cancer growth.
The mice ate a diet in which 18.5 percent of their calories – the equivalent of two servings for humans – came from walnuts. Tumors in the walnut-fed group took twice as long to double in size as tumors in the control group, the article reports.
“It’s always very good to find something that will slow the growth of tumors without being toxic chemotherapy,” said Hardman, who has spent 15 years studying the role of diet in cancer.
Walnuts have at least three components that might account for their cancer-slowing effect, Hardman said.
They are high in omega-3 fatty acids, which have been shown to slow cancer. They also have antioxidants and phytosterols, which have been shown to reduce cholesterol and may act to prevent cancer.
Though the study was only designed to determine whether walnuts had a cancer-suppressing effect, previous research suggests that Americans need to get more of their fat calories from fats rich in omega-3 and fewer calories from saturated fats.
In addition to walnuts, other good sources of omega-3 fatty acids are fish, and canola and flaxseed oils, Hardman said.
“We’re beginning to understand that your diet probably contributes to one-third to two-thirds of all cancers that develop,” Hardman said. “Making dietary changes to prevent cancer could do more to reduce deaths from cancer than chemotherapy to treat cancer.”
Hardman’s research was funded by the American Institute for Cancer Research and the California Walnut Commission. Neither group influenced study’s interpretation, reporting and findings, Hardman said.
“Changing our habits to reduce our risk, not only of cancer but other chronic diseases, such as heart disease and diabetes, could reduce our health costs that are eating us up and provide better lives for a lot of people,” said Hardman.
“I think in the future – and probably in the near future – our diet, and making dietary changes, is going to become the biggest weapon for fighting cancer.”