Soy is a popular legume of Asian origin. People who follow a vegetarian diet often use soy to replace meat. However, there is some controversy surrounding the benefits and risks of consuming soy, as some producers now genetically modify the plant.

One of those said risks hair loss. It has been reported that soy, despite its benefits, can actually cause the hair to thin, and subsequently fall out. So, why is this? 

Because soy is goitrogenic, it can affect the thyroid. Low thyroid causes baldness and thinning hair. This is especially the case in menopausal women. Products that contain soy, such as tofu, which are used in various vegetarian and vegan diets, have been shown to cause the hair to fall out, even if only on a minimal scale.  

Soy protein is also commonly used in workout meals, shakes, and supplements. But of all the supplemental proteins, it has the highest amount of Arginine per 100 gms. Arginine is extremely anabolic and is the main component in Creatine. Creatine has been shown to raise Dihydrotestosterone (DHT) levels and cause hair loss. This can be especially detrimental to the health of men's hair. 

There are so many different types of diets these days, and many of them are meat-free. The problem is, too many people are looking for ways to substitute meat, which in some cases, isn't a good thing, and one of those main substitutes is soy. Soy isn't only eaten, but it's hugely popular to drink, too. 

Soy is unique in that it contains a high concentration of isoflavones, a type of plant estrogen that is similar in function to human estrogen, but with far weaker effects. Soy isoflavones can bind to estrogen receptors in the body, thus stumping  it, and cause weaker levels of estrogenic activity. 

When the levels of estrogen drop, hair grows doesn't grow as fast, and becomes much thinner. A decrease in these hormones also triggers an increase in the production of androgens, or a group of male hormones. Androgens shrink hair follicles, resulting in hair loss on the head. Lowered estrogen levels are particularly bad for women.

In today's times, the amount of soy isoflavones in the diet has increased dramatically, and drinking 8-12 ounces of soy milk could be having a hormonal affect on the human body that was never seen in the past. There has been many cases of hair loss, particularly among non-meat eaters, as a result of consuming soy milk and soy products.

It should be noted that soy tends to cause hair loss on a minimal scale, however, people who heavily rely on soy based diets should be careful not to overconsume it, as it can case baldness and thinning hair.  

Protein, in general, is hugely beneficial to the hair, as it can help strengthen the strands and promote healthy hair growth.  Although soy is a protein, it can have the opposite effects, because of its high concentration of isoflavones, and how it lowers thyroid levels. 

Can hair loss, caused by consumption of soy, be countered?  Taking multivitamins can help reduce the effects of soy by countering its effect, but in reality, your best bet is to lower your intake of soy, or come off it completely.  Find safer meat alternatives for your hair, such as beans, chickpeas, and lentils.