High fiber, hot flashes and breast cancer

Published 10:28 pm Saturday, October 3, 2009

Doctors have always recommended a healthy diet of fruits and vegetables to patients. But for a sub-group of early-stage breast cancer survivors, following that advice may be life-changing.

A recent clinical trial has shown that a diet loaded with fruits, vegetables and fiber — and somewhat lower in fat, compared to standard federal dietary recommendations — can cut the risk of second breast cancers in survivors, specifically those who didn’t have hot flashes, by approximately 31 percent.

“Women with early-stage breast cancer who have hot flashes have better survival and lower recurrence rates than women who don’t have hot flashes,” said Ellen B. Gold, PhD., professor and chair of the University of California, Davis, Department of Public Health Sciences and first author of the study.

“Our results suggest that a major change in diet may help overcome the difference in prognosis between women with and without hot flashes.”

Typically, hot flashes are associated with lower estrogen levels, while the absence of hot flashes is associated with higher estrogen levels. Reducing the effect of estrogen is a major treatment strategy in the fight against breast cancer.

The study, led by researchers at the Moores Cancer Center at the University of California, San Diego, along with six other sites, divided its 3,088 participants, all breast cancer survivors, into two dietary groups. Half of the 447 participants who reported having no hot flashes were randomly assigned to the high-vegetable fruit diet.

The trial found that 16.1 percent of those on the special diet had a second breast cancer event, while participants on the federally recommended diet had a 23.6 percent rate of recurrence. The dietary effect was particularly larger for women who had been through menopause, with a 47-percent lower risk rate.

According to the WHEL study principal investigator, John P. Pierce, PhD., this specific dietary pattern is only significant for women with higher levels of estrogen.

“It appears that a dietary pattern high in fruits, vegetables and fiber, which has been shown to reduce circulating estrogen levels, may only be important among women with circulating estrogen levels above a certain threshold,” Pierce said.