Several plant foods contain fyto-oestrogens, naturally occurring substances in plants that resemble oestrogen, the female hormone that regulates several processes in women and men. These fyto-oestrogens or dietary oestrogens are a source of contention considering if they are beneficial or not.
A common treatment for low oestrogen levels in women is Hormone replacement therapy (HRT). It’s a treatment that replaces hormones which are at a lower level as you approach menopause. It reduces the menopausal symptoms like hot flushes, vaginal dryness and mood swings, and it also improves the bone health. However there is also leads to an increased risk of blood clots and a higher incidence of breast, ovarian and endometrial cancer.
We find these oestrogens which are given with HRT therapy also in animal products like meat, dairy and eggs, which contain oestrogen that’s identical to human oestrogen. The fyto-oestrogens we find in plants appear not to have these detrimental effects, as we see in population studies that people who consume lots of soy products (for example people in Asia) have a lower incidence of these types of cancers.
The main sources of fyto-oestrogens are soy which contain genistein, an isoflavone compound, and flax seeds, which contain lignans. Isoflavones and lignans are the two main types of fyto-oestrogens. Other sources of these compounds are sesame, fenugreek, fennel & anise seeds, oats, beans, mint and coffee.
The reason the soy fyto-oestrogens don’t have these detrimental effects is because the body has to types of oestrogens receptors, alpha and beta. Fyto-oestrogens have a particular affinity for beta-receptors. These oestrogen beta receptors we find in the bones and that’s why high soy consumption is associated with an increased bone mass. HRT and animal foods oestrogen increases the risk for fatal blood clots by causing the liver to release extra clotting factors. The liver contains solely alpha oestrogen receptors, which means that soy foods only cause these problems if they are consumed in excessive amounts.
The uterus contains as well only the alpha oestrogen receptors, which is why we see no detrimental effects here with soy consumption. Soy foods have actually shown to be protective against these health problems like prostate, breast and bowel cancer, cardiovascular disease and osteoporosis.
Most soy on the market nowadays is genetically modified (GMO) soy, This GMO soy is almost exclusively used for livestock feed and the soy products for human consumption are not of this GMO variety.
The only people who should avoid soy foods are people who have a soy allergy, which is quite uncommon compared to the most common food allergy, milk.