What are phytoestrogens?
Phytoestrogens are compounds that occur naturally in plants that have a similar chemical structure to oestrogen. The body’s oestrogen receptors treat phytoestrogens in a similar way to the oestrogen that it biologically produces.
What are soy isoflavones?
Soy is a unique food as it contains high levels of isoflavones which are a type of phytoestrogen. Soy isoflavones have the ability to bind with the body’s oestrogen receptors and cause either a weak oestrogenic or anti-oestrogenic activity depending on the stage that the woman is at in her reproductive life cycle. As women get closer to menopause, these phytoestrogens can help to regulate hormones and ease some of the unpleasant symptoms of perimenopause.
There has been much debate about the safety of soy over the years causing some people to reject it for fear that it may cause cancer or thyroid problems. The Harvard School of Public Health has analysed the literature and published the following statement:
Soy is a unique food that is widely studied for its estrogenic and anti-estrogenic effects on the body. Studies may seem to present conflicting conclusions about soy, but this is largely due to the wide variation in how soy is studied. Results of recent population studies suggest that soy has either a beneficial or neutral effect on various health conditions. Soy is a nutrient-dense source of protein that can safely be consumed several times a week, and is likely to provide health benefits—especially when eaten as an alternative to red and processed meat.
The benefits of phytoestrogens
- Foods that are rich in phytoestrogens are highly nutritious and beneficial as part of a balanced diet.
- One third to one half of women have a specific gut bacteria that can convert phytoestrogens to a more potent form which may relieve hot flushes.
- Phytoestrogens may be beneficial in relieving menstrual issues related to perimenopause.
- Phytoestrogens may assist with the reduction of bone loss and osteoporosis.
- Phytoestrogens may reduce the risk of breast cancer in women with a low risk profile. Please note, women who have previously had breast cancer or are considered to be at high risk are advised not to take soy supplements.
- Phytoestrogens may support healthy functioning of the heart.
Top phytoestrogen containing foods
- Soy beans / soy nuts
- Soy milk
- Soy yoghurt
- Sesame seeds
- Miso paste
- Flax bread
- Multigrain bread
How much phytoestrogen to eat during perimenopause
Whole foods are always recommended over supplements. For a therapeutic effect, examples of the daily quantities of foods you should eat (eat one of these or a combination of them):
- 200g of tofu
- 100g of tempeh
- 1/2 to 1 litre of soy milk
- 45g of ground flaxseeds
Resources and links for further reading: