Preliminary data from a phase II pilot study suggest that flaxseed may be a useful alternative to estrogen in the management of hot flashes, according to Dr. Sandhya Pruthi of the Mayo Clinic, Rochester, Minn., and associates.
A 6-week regimen of crushed flaxseed, given at 40 g daily, decreased the number of hot flashes from a mean of 7.3 per day to 3.6 per day in women who did not wish to receive estrogen therapy, Dr. Pruthi and associates reported in the Journal of the Society for Integrative Oncology.
Estrogen therapy has been the effective hot-flash treatment most commonly used, but fears that it may cause breast cancer have made many postmenopausal women reluctant to take it for their menopausal symptoms. Their concerns have prompted a search for nonhormonal alternatives.
The authors tested the tolerability and effect of flaxseed therapy in 28 women who had at least 14 bothersome hot flashes per week for more than 1 month before study entry. Participants were instructed to sprinkle 2 tablespoons of crushed flaxseed on cereal, in juice, in yogurt, or on fruit twice daily for 6 weeks. Each tablespoon provided 10 g of flaxseed, and the women were instructed to drink at least 150 mL of liquid for each 10 g of flaxseed they consumed (J. Soc. Integr. Oncol. 2007;5:106–12).
In the last week of flaxseed therapy, the hot-flash score—a measure of hot-flash frequency and severity—decreased by a mean of 57%, with a median decrease of 62%. The mean decrease in the number of hot flashes per day (from 7.3 to 3.6) was significant. Participants also reported a statistically significant improvement in quality of life, with less anger, anxiety, and fatigue at the end of the trial than at the beginning.
Abdominal distention or bloating was experienced by half of the women at some time during the study, and six women failed to complete the full 6 weeks of flaxseed therapy because of abdominal toxicities, weight gain, or taste intolerance, the authors reported. “These issues need to be evaluated further in a placebo-controlled manner. It is possible that initiating flaxseed therapy at a lower dose—and titrating the dose upward—may decrease abdominal toxicities,” Dr. Pruthi and associates wrote.
Flaxseed contains weak estrogenic properties that “seem to account for the most likely mechanism of its effectiveness in reducing hot-flash activity,” according to the investigators.