The battle against breast cancer may have a new weapon, but it's not surgery or a new drug. It's the food we are eating.
A study presented at a gathering of the American Society of Clinical Oncology in Orlando, Florida, Monday afternoon, suggested that a low-fat diet had helped some women prevent their breast cancer from returning.
"The finding is significant," says Dr. Rowan Chlebowski of UCLA Medical Center, who led the study. "This represents the first time we've demonstrated a lifestyle intervention may impact breast cancer outcome."
Researchers from the University of California Los Angeles studied more than 2,437 middle-aged and elderly women with early stage breast cancer. Some followed a standard diet filled with meat, butter and fried foods that added up to about 51 grams of fat a day. The rest followed a lower fat diet averaging 33 grams of fat a day.
Over the course of the five-year study, subjects met with nutritionists eight times and had their eating habits checked with random telephone calls.
At the end of the study, the researchers found that while 12.4 per cent of women on a standard diet had their breast cancer return, only 9.8 per cent of those on the low-fat diet had a recurrence.
It's a modest but an important reduction in the disease that equals the effects of some new drugs.
"This is telling us that women can now look at doing something actively or proactively to change their breast cancer outcome," says Dr. Pam Goodwin of Mt. Sinai Hospital in Toronto.
About 80 per cent of breast cancers are fueled in part by the hormone estrogen, which is made by fat cells. Previous studies have shown that low-fat diets reduce the risk of breast cancer and doctors had thought it might be because fat cells produce estrogen.
The most pronounced effect was in the 20 per cent of women whose tumors were hormone-receptor negative, meaning they do not respond to estrogen.
In that group, the low-fat diet reduced the risk of cancer coming back by 42 per cent over the five years.
Women on the low-fat diet also lost on average five pounds. Researchers don't know if it's the weight loss or the healthier food that kept the cancer at bay.
Although Chlebowski and other experts said the findings needed to be confirmed by additional research, the results are compelling enough that some Canadian hospitals will start encouraging newly diagnosed women to adopt low-fat diets.
Many medical experts remain skeptical, however, that cutting fat consumption affects cancer risk.
"There are more questions than answers," Dr. Eric Winer of the Dana-Farber Cancer Institute in Boston said. "What we don't want to happen is for every woman who's had breast cancer to panic if she's had a Big Mac."
With a report from Avis Favaro and Associated Press
