Many supplements targeted at perimenopausal and menopausal women contain phytoestrogens but what are they and can they help reduce hot flushes?
Phytoestrogens are plant compounds similar to the estradiol (estrogen) produced in your ovaries. The main types include isoflavones (see our article, Isoflavone supplements for more information), lignans (from flaxseed and grains), stilbenes (grapes, peanuts, berries, conifers), and coumestan (alfalfa, sprouts, legumes).
Phytoestrogens are often included in combined supplements marketed at perimenopausal or menopausal women.
RELATED: Do I need supplements during menopause?
How do phytoestrogens work?
Phytoestrogens mimic the effects of estradiol – they have a similar but different chemical structure and can bind to many estrogen receptors in your body to stimulate estrogen responses. However, phytoestrogens don’t have the same potency as the estradiol produced by your body, so will not have the same effect. Also, when they bind to some receptors they can block the effects of your body’s natural estradiol.
How effective are phytoestrogens?
There is some evidence that phytoestrogens can help decrease vasomotor symptoms (hot flushes and sweats) associated with menopause [1].
There is mixed evidence regarding phytoestrogens improving anxiety and depression in menopausal women, suggesting some potential but that more studies are needed [2].
There is no current evidence to support phytoestrogen supplements improving postmenopausal quality of life [3].
RELATED: Am I depressed or menopausal?
What are the side effects?
Phytoestrogens are usually well tolerated, and side effects tend to be mild and mostly gastrointestinal, such as abdominal pain, as well as sleepiness.
Who can take them?
You should avoid phytoestrogens if you are pregnant or breastfeeding and speak to your healthcare professional if you are using hormonal contraception.
If you have, or have had, a hormone-sensitive cancer, you should discuss phytoestrogens with your healthcare professional before taking them. The potential interaction between phytoestrogens and tamoxifen is complex and should be discussed with your healthcare professional.
RELATED: A guide to menopause if you've had breast cancer?
What’s the bottom line?
The most effective evidence-based treatment for perimenopausal and menopausal symptoms is HRT because it targets the underlying cause – low hormones. Also, HRT is bone, heart and neuro-protective, and reduces all-cause mortality by 30% [4].
Any herbal supplement should be chosen with care – they are not tested and regulated in the same way as medications and the purity and quality of ingredients can’t be guaranteed.
