Phytoestrogens – Dietary Oestrogens

Phytoestrogens, also called ‘dietary oestrogens’ are a diverse group of naturally occurring non-steroidal plant compounds that are structurally similar to the estradiol (17-β-estradiol) and have the ability to cause oestrogenic or/and anti-oestrogenic effects. Phytoestrogens get their name from the Greek word ‘phyto’ meaning plant and ‘estrogens’ meaning the hormone which gives fertility to the female mammals.

 

At molecular level, phytoestrogens are similar to oestrogens and this similarity allows them to mildly mimic and sometimes act as antagonists of oestrogen. Due to their chemical structure, phytoestrogens have a propensity to attach to a particular oestrogen receptor. This is thought to be one of the underlying mechanisms by which phytoestrogens compounds might elicit an effect in the body.

 

Phytoestrogens are considered to be milder than woman’s intrinsic oestrogen and exert their effects primarily through binding to oestrogen receptors . When oestrogen levels are high, phytoestrogens compete with oestrogen for receptor sites, reducing oestrogen ability to bind to receptors thereby lessening its effect. On the other hand, when oestrogen levels are low as in the peri or post menopause, phytoestrogens act as oestrogen supplements.

 

Phytoestrogens occur in plants and plant products that include soy beans, grains, seeds, herbs, fruits and vegetables.

 

Herbs that have phytoestrogen effects include Red Clover, Liquorice, Thyme and Verbena. Herbs that mimic the effects of estrogens include Black cohosh, Dong Quai and Ginseng.