Dietary Fat Reduction and Plasma Estradiol Concentration in Healthy Postmenopausal Women

Abstract
Concentrations of total and weakly bound plasma estradiol were significantly ( P <.01) reduced in 73 healthy postmenopausal women after 10–22 weeks of participation in a low-fat diet intervention program. Nonsignificant reductions in estrone sulfate and sex hormone-binding protein were also observed. The 17% reduction in average estradiol concentration was accompanied by an average reduction of 12 mg/dL in total plasma cholesterol ( P <.001), an average weight loss of 3.4 kg ( P <.001), and an average reduction in daily dietary fat from 68.5 to 29.5 g. Our review of case-control studies indicates that a 17% reduction in plasma estradiol may explain a noteworthy component of the international variation in breast cancer incidence. We find a need for further studies of ( a ) disease risk in relation to hormone concentrations and ( b) changes in hormone concentrations as a function of the duration of low-fat diet intervention. [J Natl Cancer Inst 82: 129–134, 1990]