Research published in the American Journal of Clinical Nutrition (December 2007; Vol. 86, No. 6:1730–1737) suggests that higher dietary fiber intake may reduce a woman’s risk of endometrial cancer. An analysis of data from seven case-control studies found that increasing fiber intake by an additional five grams per 1,000 calories was associated with a reduction in endometrial cancer risk of more than 20%. Prolonged exposure to estrogen without adequate progesterone is known to increase endometrial cancer risk, and one proposed mechanism is that dietary fiber helps regulate estrogen levels, potentially reducing excess hormonal exposure.