Flaxseed, or Linum usitatissimum, comes from the annual herb plant called flax. Since the time of ancient Egypt, people have used flaxseed and flaxseed oil for their supposed medicinal properties. Modern usage has shown that flaxseed can be beneficial for some conditions. However, the evidence for use of flaxseed as a natural alternative to hormone replacement therapy, or HRT, to minimize symptoms of perimenopause is not conclusive. As with any alternative therapies, you should talk to your doctor before using flaxseed for your hot flashes.
Perimenopause
In medical terms, menopause is the lack of menstrual periods for 12 consecutive months. Perimenopause is an ill-defined period in which a woman continues to menstruate, but less regularly, and begins to show signs of declining estrogen levels and impending menopause, such as hot flashes, vaginal dryness and mood swings. A woman who is "going through menopause" is perimenopausal.
Clinical Trials
The University of Maryland Medical Center summarizes the available clinical data about the use of flaxseed in perimenopausal women. One trial claimed that 40 grams of flaxseed was comparable to standard hormone replacement therapy for women suffering from hot flashes due to impending menopause. Other trials of flaxseed oil reported no benefits to symptoms of menopause.
Strength of Evidence
The Mayo Clinic rates the available scientific evidence for the effectiveness of flaxseed in treating mild symptoms of menopause with a grade of "C," signifying that the evidence is suggestive of a benefit but not conclusive. In other words, flaxseed might or might not help with symptoms of impending menopause, and more studies must be done before doctors could advise women about the use of flaxseed.
Active Compounds
Flaxseed has two medically active components. Flaxseed and flaxseed oil have high levels of a precursor to omega-3 fatty acids that might improve heart health. Flaxseed, but not its oil, also contains a class of compounds called lignans that act as antioxidants. Lignans can also bind to estrogen receptors, with the effect of activating them or turning them off, depending on the dosage.
Mechanism
Flaxseed, but not flaxseed oil, can mimic the effects of estrogen on cells and bind to estrogen receptors. During the menopausal transition, a woman's ovaries make less and less estrogen, causing a multitude of symptoms. The estrogen-like activity of flaxseed is the basis for clinical trials to compare its effects versus traditional hormone replacement therapy for menopause.
Cautions
In general, people tolerate flaxseed and flaxseed oil well and with a minimum of side effects, according to the Mayo Clinic. However, because of its possible estrogenic actions, the clinic cautions that women with estrogen-sensitive conditions such as uterine fibroids, polycystic ovary syndrome or ovarian, breast or uterine cancer should not use flaxseed. Women who take daily flaxseed powder might notice a change in the regularity of their periods, making it difficult to sort out the effects of flaxseed and the effects of impending menopause.
