A diet high in fiber may help reduce the risk of breast cancer, researchers report.
The review, published in the journal Cancer, pooled data from 20 prospective studies on fiber intake and breast cancer incidence. Some have looked at total fiber intake; others looked at the different types of fiber from grains, fruits, vegetables and legumes; none involved fiber supplements.
Compared with women with the lowest overall fiber intake, those with the most fiber have an 8% reduced risk of breast cancer.
The researchers also found that only soluble fiber, the one that predominates in foods like oatmeal, nuts, beans, peas and lentils, had a statistically significant association with a reduced incidence of cancer. breast. Insoluble fiber – those found in whole grains that add bulk to stools – was suggested to reduce the risk as well, but the effect was not statistically significant. (Soluble and insoluble fiber are found in varying proportions in most foods containing fiber.)
Most of the studies looked at postmenopausal breast cancer, but in five reports examining premenopausal cancer, the effect of fiber was even greater – a risk reduced by 18% for those who consumed the most.
“These are observational studies that do not prove the causal link,” said lead author Maryam S. Farvid, a researcher at Harvard. “But there are very few modifiable risk factors for breast cancer, and identifying them, even those with a small effect, is important.”