Evaluation of the Aromatase Inhibition Potential of Freeze-Dried Grape Powder

Objective: To determine the role of freeze-dried grapes as a potential aromatase inhibitor by testing of plasma hormone levels. Methods: A six-week study was conducted involving postmenopausal women during which 94 g of freeze-dried grape powder was consumed in addition to their usual diet. Plasma hormones were measured before and after the treatment. Results: Of the 18 women involved in the study, average age and body mass index were 61.4 years and 24.4 respectively. For the hormone levels studied, the following median (interquartile range) percentage changes from baseline to six-week values were found: estradiol +11.8% (-34.4%, +44.2%), p =.42; estrone +3.4% (-15.7%, +12.9%), p =.64; estrone sulfate +5.3% (-19.9%, +56.3%), p =.35; testosterone-1.5% (-14.7%, +10.7%), p =.97; and androstenedione +12.6% (-17.1%, +49.1%), p =.15. The hormone levels did not significantly change between baseline and six weeks. Further, the changes that were observed did not tend to go in the hypothesized direction (estrogens and conjugates increased slightly, and testosterone decreased slightly). Only androstenedione showed a trend toward change in the hypothesized direction. Conclusions: In this study, there was no evidence that plasma hormone levels are altered by six weeks of daily consumption of 94 g of freeze-dried grape powder.