Effect of Prune Consumption on the Ratio of 2-hydroxyestrone to 16a-hydroxyestrone

JOURNAL: American Journal of Clinical Nutrition 76 (2002): 1422-1427

AUTHORS: Kasim-Karakas, S.E., Almario, R.U., Gregory, L., Todd, H., Wong, R. and Lasley, B.L.

High fiber intake has been associated with a decreased breast cancer risk. This study investigated the effects of prunes as a source of fiber on the concentrations and ratios of two estrogen metabolites: 2OHE1 and 16aOHE1. A higher urinary ratio of 2OHE1 to 16aOHE1 may be associated with a lower risk of breast cancer. Healthy premenopausal women ate their usual diet for three menstrual cycles and then consumed 100 grams (10-12 prunes) for the next three cycles. Urinary 2OHE1 and 16aOHE1 were determined during the follicular and luteal phases. Prune supplementation significantly decreased excretion of 16aOHE1 during the follicular phase of the first menstrual cycle and during the luteal phases of the first and third menstrual cycles. The 2OHE1 to 16aOHE1 ratio did not change significantly. The significance of the decrease in 16aOHE1 without a change in ratio of the two estrogen metabolites on the prevention of estrogen-dependent cancers remains to be determined.