High Fiber consumption may lower breast cancer risk

Dietary fiber found mainly in fruits, vegetables, whole grains and legumes has health benefits from relieving constipation to helping maintain a healthy weight and lowering risk of diabetes and heart disease. But current evidence from randomised controlled trials on the effects of dietary fibre intake on breast cancer risk is inconsistent.A new study has evaluated role of dietary fiber in breast cancer.

Researchers have found in an analysis of all relevant prospective studies that consumption of a diet high in fiber was linked with a reduced incidence of breast cancer. The findings of the study have been published early online in CANCER, a peer-reviewed journal of the American Cancer Society (ACS).

Breast cancer is the most common carcinoma in women worldwide. Ecological and migrant studies have provided strong evidence that environmental factors, including lifestyle and dietary factors, are related to breast cancer risk.

Because studies have generated inconsistent results regarding the potential relationship between fiber intake and breast cancer, Maryam Farvid, PhD, of the Harvard T.H. Chan School of Public Health, and her colleagues searched for all relevant prospective studies published through July 2019.

When the investigators pooled data from the 20 observational studies they identified, individuals with the highest consumption of fiber had an eight percent lower risk of breast cancer. Soluble fiber was associated with lower risks of breast cancer, and higher total fiber intake was associated with a lower risk in both premenopausal and postmenopausal women.

"Our study contributes to the evidence that lifestyle factors, such as modifiable dietary practices, may affect breast cancer risk," said Dr. Farvid. "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."

Importantly, the findings do not demonstrate that dietary fiber directly reduces breast cancer risk, and a randomized clinical trial is needed to test such cause and effect.

Full Citation: "Fiber consumption and breast cancer incidence: a systematic review and meta-analysis of prospective studies." Maryam S. Farvid, Nicholas D. Spence, Michelle D. Holmes, and Junaidah B. Barnett. CANCER; Published Online: April 6, 2020 http://dx.doi.org/10.1002/cncr.32816