Determine the efficacy and tolerability of omega-3 fatty acids versus soybean isoflavones in reducing the vasomotor symptoms (VMSs) frequency in postmenopausal women. A randomized, prospective, two-arm study was performed in healthy postmenopausal women aged 45-65. The two arms were: two capsules/day of omega-3 (425 mg of omega-3/capsule) administered orally (n = 38) and two tablets/day of soybean isoflavones (54.4 mg of isoflavones/tablet) (n = 30), over 16 weeks. The mean baseline frequency of moderate and severe VMSs per week in the omega-3 group was 24.56 and 23.90, respectively, and 19.65 and 19.51 in the isoflavone group. After 4 months, the reduction in moderate and severe hot flashes with omega-3 was significant (p < .001), whereas in the case of isoflavones, there was a significant difference in severe (p = .02) hot flashes after 4 months, but not in moderate hot flashes (p = .077). Omega-3 did not demonstrate significant efficacy differences versus isoflavones over time. The use of omega-3 has a beneficial effect on hot flash reduction after 4 months of treatment. This is comparable to the benefits found with soybean isoflavones after 3-4 weeks and after 4 months in severe hot flash women, but higher than those found with soybean isoflavones in moderate symptom women.
Keywords: Vasomotor symptoms; hot flashes; omega-3; soybean isoflavones.