Omega-3 Fatty Acid Supplementation Lowers Serum FSH in Normal Weight But Not Obese Women

Context: Dietary omega-3 fatty acids delay ovarian aging and promote oocyte quality in mice. Objective: To test whether dietary supplementation with omega-3 polyunsaturated fatty acids (PUFA) modulates reproductive hormones in reproductive-age women. Design: Prospective interventional study. Setting: Academic center. Participants: Fifteen obese and 12 normal-weight (NW) eumenorrheic women, ages 28-34 years. Intervention: Two frequent blood-sampling studies were performed before and after 1 month of omega-3 PUFA supplementation with 4g of eicosapentaenoic acid and docosahexaenoic acid daily. Main Outcome Measures: Serum LH and FSH (basal and after GnRH stimulation). Results: The ratio of omega-6 to omega-3 PUFA was significantly reduced in plasma and red blood cell components for both groups after treatment (both P < .01). Omega-3 PUFA supplementation resulted in reduction of FSH and FSH response to GnRH by 17% on average (P = .06 and P = .03, respectively) in NW but not obese women. Serum levels of IL-1 beta and TNF-alpha were reduced after omega-3 PUFA supplementation (-72% for IL-1 beta; -56% for TNF-alpha; both, P < .05) in obese but not in NW women. This reduction, however, was not associated with a hormonal change in obese women. Conclusions: Dietary administration with omega-3 PUFA decreased serum FSH levels in NW but not in obese women with normal ovarian reserve. This effect is intriguing and is directionally consistent with murine data whereby higher dietary omega-3 PUFA extends reproductive lifespan. Our results imply that this nutritional intervention should be tested in women with diminished ovarian reserve in an attempt to delay ovarian aging.