April 6 (UPI) -- A diet rich in fiber may reduce a woman's risk for breast cancer, a new study has found.
Regular consumption of high-fiber foods was found to reduce risk for the disease by 8 percent overall, according to an analysis of existing research published Monday in the journal Cancer.
The findings were consistent for both pre- and post-menopausal women, researchers report.
"Our findings provide research evidence supporting the American Cancer Society dietary guidelines, emphasizing the importance of a diet rich in fiber, including fruits, vegetables, and whole grains," study co-author Dr. Maryam Farvid, of the Harvard T.H. Chan School of Public Health, said in a press release.
Guidelines for nutrition and physical activity for cancer prevention from the American Cancer Society don't recommend specific amounts of daily fiber intake, though they do suggest a diet rich in fruits and vegetables at every meal, whole-grain breads, pastas and cereals and brown rice instead of white.
Farvid and her colleagues analyzed data from 20 previously published studies assessing fiber intake and breast cancer risk. Higher total fiber intake was associated with an 18 percent lower risk of breast cancer in pre-menopausal women and 9 percent lower risk in post-menopausal breast cancer.
They also found that consumption of soluble fiber was associated with a 10 percent reduction in breast cancer risk and that insoluble fibers appear to reduce risk by 7 percent.
Soluble fiber is found in oat bran, barley, nuts, seeds, beans, lentils, peas and some fruits and vegetables. Insoluble fibers, which don't dissolve in water, are found in fruits and vegetables commonly referred to as "roughage."
While the researchers are quick to emphasize that the findings "do not demonstrate that dietary fiber directly reduces breast cancer risk," they point out that it falls in line with other advice for decreasing risk for the disease.
"Our study contributes to the evidence that lifestyle factors, such as modifiable dietary practices, may affect breast cancer risk," Farvid said.