In an analysis of all relevant prospective studies, a reduced incidence of breast cancer was associated with high fiber intake. Results are published online early cancerA peer-reviewed journal of the American Cancer Society (ACS).
Because studies have produced inconsistent results regarding the possible relationship between fiber intake and breast cancer, Maryam Farvid, PhD, of the Harvard TH Chan School of Public Health, and her colleagues searched for all relevant prospective studies published through July 2019.
When the investigators combined data from the 20 observational studies they identified, people with the highest fiber intake had an eight percent lower risk of breast cancer. Soluble fiber was associated with a lower risk of breast cancer, and higher total fiber intake was associated with a lower risk in premenopausal and postmenopausal women.
“Our study contributes to the evidence that lifestyle factors, such as modifiable dietary habits, can affect breast cancer risk,” said Dr Farvid. “Our results provide research evidence supporting the American Cancer Society dietary guidelines, emphasizing the importance of a fiber-rich diet, including fruits, vegetables and whole grains.”
Importantly, the results do not show that dietary fiber directly reduces the risk of breast cancer, and a randomized clinical trial is needed to test such cause and effect.