Soy is one of the cheapest and easiest proteins on the market, often used as a replacement for meat by vegetarians and vegans.  

But there are many claims dogging the heels of this food about it’s potential health effects. 

The debate over the health benefits and adverse effects of soy products isn’t new and has caused confusion in the general public over what’s true and what’s exaggerated. 

The majority of controversy comes from the fact that soy products contain isoflavones, which mimic human estrogen in the body. Depending on how you see it, this fact could attract you or scare you away from soy products, but let’s go through the truths and myths:

Myth: Males who intake soy products will see negative effects with resistance exercise 

There was one study that showed that supplementing with soy protein ‘blunted’ testosterone levels and that whey protein decreased cortisol (stress) response after a session of resistance training — or picking up heavy things and putting them back down. 

However, this study oversimplified the hormone pathway and underemphasized that estradiol levels, or the active form of estrogen, weren’t changed. This study doesn’t show soy will affect how heavy you can lift, there’s no evidence for that. 

Everything in moderation is good and excess supplemental protein of any type can be harmful.

Undetermined: Soy products make males infertile

While a fear that circulated for some time, this simply has little scientific evidence behind it. The only trials showing a negative effect on fertility or male circulating estrogen levels were done in rats and didn’t translate to human studies. Simply put, this means when they tested males by giving them soy diets, they found no difference in the circulating hormone levels than non-soy diets. Different studies show conflicting results, and scientists have been unable to come to a consensus on this question. 

Truth: Soy products can help to protect you against heart disease and better glycemic control in type 2 diabetics

This is a claim that is supported by the FDA who released a statement echoing that soy products are good for your heart. They lack the saturated fat contained in many animal proteins. Yet, another randomized and double blinded study showed further that in type 2 diabetics they found that blood sugar levels were better controlled and heart risk markers were reduced.

While some questions remain unanswered about soy products, the evidence about their downfalls is contradicted by positives about their healthiness. Keep in mind that soya products are highly processed food and everything is good in moderation, but there’s no reason why you can’t toss some fried tofu on top of a salad to give it some extra protein.