Soy and Estrogen
The age-old question, does soy effect my estrogen?
Soy products refers to foods made from soybeans, and includes:
- Soy milk
- Soy yoghurt
- Textured vegetable protein (TVP)
- Isolated soy protein powders
- Miso paste
- Soy sauce
Soybeans are a complete protein source (having a full amino acid profile) and a dietary staple in many cultures. Soy contains phytoestrogens (‘phyto’ meaning plant-derived), plant compounds that have estrogen like structures called isoflavones. Many other plant foods also contain isoflavones, including flaxseeds and whole grains, though soy is the most significant dietary source.
The effects of soy isoflavones on human estrogen levels are complex. Soy is safe for everyone to consume in moderate consumption. The isoflavones in soy (daidzein, genistein and glycitein) are structurally similar, though not identical to human estrogen, and as such, can bind to estrogen receptors in the body. However, compared with human estrogen, phytoestrogens are known to exert a much weaker effect in the body. So are often called weak estrogens.
How much is safe to have each day?
1 serve of a soy product contains around 7g of protein and 25mg of isoflavones, and is equal to:
- 100g firm tofu
- 50g tempeh
- 1 cup soy milk
- ½ cup edamame
Soy is a unique food that contains all essential amino acids and can be safely consumed in moderation.