There is probably no other food (other than perhaps gluten/wheat) that stirs up more controversy than soy. Rather than ‘pick sides’ and point to studies that support or deny different health claims about soy, here is a distilled down version of the research that is currently out there:
- Soy is a rich source of isoflavones. These isoflavones make soy helpful in some cases…and potentially harmful in others.
- Soy is probably best known for easing menopausal symptoms (particularly hot flashes). Many studies support soy’s benefits in this regard.
- Soy can be a solid option for those people (men and women) who need to control their cholesterol.
- Soy isoflavone supplementation appears to improve endothelial function in blood vessels among postmenopausal women with low baseline flow-mediated dilation levels.
- Concern exists that soy isoflavones could speed up the proliferation of estrogen dependent breast cancer cells. However, a multitude of studies suggest that soy may actually help to combat breast cancer.
- A recently published meta-analysis concluded that soy has “no detrimental effects on risk of breast cancer recurrence and, in some cases, significantly reduce the risk.”
- There are a few circumstances in which soy or isoflavone supplements may not be recommended:
- Soy is a goitrogen—a food that potentially increases the risk of goiter.
- If you currently have a thyroid condition like hypothyroidism or Hashimoto’s thyroiditis, consider eliminating or drastically limiting your intake of soy and isoflavone supplements.
- Estrogen-dominant women should avoid soy and soy products.
- In infants fed soy-based formula, there is growing concern that the high phytoestrogen content could accelerate puberty and cause reproductive or thyroid disorders later in life.
- Organic whole or fermented soy products such as edamame, miso, tempeh and tofu are the best options if you are going to eat soy.
- Soybeans are one of the top genetically engineered crops. Finding organic at your average grocery store can be difficult.
