DIETARY-FAT REDUCTION AND PLASMA ESTRADIOL CONCENTRATION IN HEALTHY POSTMENOPAUSAL WOMEN

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] © 1990 Oxford University Press.