Is soy bad for men? If you’re reading this article, you’re probably interested in having some soy foods, and you’re wondering, are these things going to kill my testosterone levels? Are they going to give me man boobs, and all my gains going to be destroyed? We’ll cover all that in this article and show you the real research that supports the claims on whether or not soy is actually bad or good for you.
To start looking into this topic, we need to look at soy itself as a plant, which makes it a little bit unique because it has a compound class called phytoestrogens. Phytoestrogens are plant compounds that look a lot like human estrogen, meaning they bind to estrogen receptors.
Men and women both have estrogen receptors and estrogen. Women just have higher estrogen amounts than men and more estrogen receptors in certain tissues like their breasts, uterus, etc. But men also have estrogen receptors in those same areas.
So, some of the concern around soy is that soy has these phytoestrogens called isoflavones. We’re wondering if we have a lot of soy because that means that we’re going to increase our estrogen levels as guys, and is that going to kill our testosterone production. There’s been a lot of concern about this because more people are going vegan and vegetarian, incorporating soy in.
Thankfully, we have some studies here that actually give us the hard-line answers. There was a meta-analysis of 15 different randomized clinical trials, and this is great because the meta-analysis takes all the research and kind of research looking at the research. It’s the big summary of what we know, and here’s what the conclusion of this giant meta-analysis of the 15 trials said:
“The meta-analysis showed that soy supplementation had no significant effect on total testosterone, free testosterone, sex hormone-binding globulin in men when men were consuming soy foods and soy protein powders in the 10 to 70 grams per day amount.”
This is great news for anyone who wants to include some soy protein into your diet. The research showed that if you’re under 70 grams per day amount of soy, that had no effect on testosterone levels. And that is quite a bit of soy – that’s like three scoops of soy protein powder or like probably like 6 different cups of soybeans per day – you’d have to eat a lot of soy to go over that.
So you can certainly have some soy protein powder or have some soybeans or some tofu in your diet, and it’s not going to affect your testosterone levels.
The study also shows that in athletes specifically when they were following a 12-week resistance training program and then either supplemented with whey protein post-workout or soy protein, they had the same muscle gains and strength gains.
Soy is not going to be inferior to way if you’re having an overall good training plan and a good diet with enough protein. For the average person, soy is good to go as long as it’s organic soy – you want to make sure you’re getting high-quality soy because soy is one of the largest genetically modified crops on the plane, and unfortunately, some of this highly processed non-organic soy is sprayed with all sorts of pesticides and those may have some deleterious effects.
The other thing that is important to know is there is some research that shows that insanely high intakes of soy have been shown to have negative effects on men. There was a guy, for example, in one of these case studies that show that he was drinking the equivalent of three quarts – 2.8 liters of soy milk per day that did have symptoms of erectile dysfunction.
And there was also another thing of a young vegan who is having over almost 150 grams of soy per day, and that particular individual did experience some symptoms of low testosterone and hypogonadism.
So what we can take away from this is that normal soy intakes under 70 grams are gonna be fine, but if you’re getting into huge intakes of these soy isoflavones, we could get into some trouble. But for the average person, that’s just not it’s going to happen.
In fact, soy may actually confer health benefits to you as a man with the research also shows is that soy intakes are positively correlated with a healthier heart. It improves the endothelial function, meaning all of your different arteries and veins have this cell line called the endothelium.
We want to keep those cells healthy, and soy does improve endothelial function. It can lower your cholesterol levels in men, and it can reduce your risk of prostate cancer by up to 40%, which is something we also have to think about because prostate cancer is the second leading cancer in men. So, it’s important to look at, and soy can lower prostate cancer risk.
The way we stand on it is that don’t be afraid of soy. We can show up some pictures of 100% vegan bodybuilders who definitely include soiling their diets, and they look just fine. We don’t think they’re losing muscle or showing estrogenic properties of soy, so don’t avoid your soybeans.
We hope this calmed down your fears, and if you want to include soy in your diet, don’t forget about hemp and rice some of these other different plant-based protein powders because plants are best when they’re combined together for a full amino acid profile.