The relationship surrounding the consumption of soy and testosterone in men continues to this day, where evenly split into both sides of the debate are people that support regular consumption of soy, and those who oppose it; most commonly bodybuilders and other athletes that view it as one of the worst developments in history.
Soy can lower testosterone levels if consumed in large quantities. Soy contains isoflavones which mimic the effects of estrogen. My advice is to stay away from Soy where possible.
Let’s have a look at soy protein a little closer, so we can determine how it truly affects testosterone levels.
Soy Protein And Additives Are Found Everywhere
Every single day, regardless of your stance on soy, you eat some foods that contain soy protein in it or some form of modified soya bean oil. Though it may not be immediately noticeable since you think you are eliminating all sources of it, there is the possibility that your testosterone levels could have already been affected by it, all without you even knowing.
Why do so many food products contain soy? Because it is cheap. The vast majority of commercially used soybean today have been genetically modified so that it is cheaper and easier to obtain by manufacturers.
How Does Soy Impact Testosterone Levels?
Soy products are known to have compounds in them called isoflavones, which share a chemical structure closely related to that of estradiol, the body’s primary estrogen. Even though this hormone is produced in men as well as women, men need far less of it and are much more prone to experiencing adverse effects as a result of high levels.
These isoflavones found in soy (there are three primary ones known as genistein, daidzein, and glycitein) are all potent phytoestrogens; plant-based, estrogen-like compounds which act much in the same way as the natural hormone when consumed.
This is not good, and why men should avoid the consumption of excessive amounts of soy protein. Keyword being excessive. There is a certain amount that you will be exposed to every single day, whether through recklessness or inadvertent consumption, but in the same way that a drop of ink that falls into the ocean will not have a long-lasting effect, such is the worry about tiny amounts of soy protein consumption.
What Happens In The Body When Soy Protein Is Consumed?
There have been a number of studies conducted that highlights exactly what soy protein causes once consumed, which is exactly what we need to look at when making a definitive judgment. Interestingly, one of the largest manufacturers of soy products in the world SOYJOY is a major funding partner of the Academy of nutrition and dietetics, one of the major US policymakers regarding dietary guidelines to the public.
Not surprisingly, as a result, this very same policymaking body “advises” that men consume two servings of soy products daily for optimal health. Yeah, sure.
Men That Consume Soy Protein Have High Levels Of Equol In Their Blood
If you’ve never heard of Equol before, that’s understandable as it’s not something that the world’s prominent health authorities are keen on sharing. However, this compound is an estrogen, made via the metabolism of one of soy’s isoflavones, daidzein.
This estrogen is produced via our normal probiotic bacteria, which is bad as is, also has a very strong anti-androgen property, being able to significantly reduce luteinizing hormone release, which in turn will suppress testosterone production.
This is not where the bad news ends, however, as in addition to this it also attacks our most powerful androgen, dihydrotestosterone-better known as DHT, by binding to it and making it incapable of interacting with androgen receptors.
This can set into motion catastrophic effects on male hormonal health, as high estrogen levels coupled with the loss of DHT’s reducing effects on them sets the stage for absolute estrogen dominance.
Loss Of Libido And Erectile Dysfunction
There was another popular study conducted that followed a 19-year-old man, diagnosed as type I diabetic but in otherwise excellent health, who suddenly observed loss of interest in sex and erectile dysfunction after adopting a vegan diet high in consumption of soy products.
Initial blood work indicated decreases to free and total testosterone, even though DHEA was higher than normal. DHEA, being a prohormone of sorts, can convert into either androgens or estrogens, and since we know testosterone levels were lower than normal, the most logical conclusion would be that the direction favored production of estrogens.
Regardless, to remedy the situation, cessation of the vegan diet was recommended, and over the course of the following year, full sexual function was regained. Normalization of hormone values coincided with improvements to libido and erectile potency, which show tell you that soy products were the culprits that led to its reduction in the first place.
Related: 7 Foods that Lower Libido
Soy Products May Impair Normal Development Of Male Fetus In The Womb
Though not a direct implication for adult men, women that consume diets high in soy protein and other products may inadvertently affect the health of the male fetus, as rodent studies conducted found that normal development of sexual organ health was adversely affected.
In adult men, excessive consumption of soy protein has been correlated with reduced sperm count, which can interfere with fertility and reproductive health. If you and your lady friend are vegan and trying to conceive, be very careful about overall soy consumption as things can turn out bad.
Effect Of Soy Protein On Testosterone Levels- Summary
Consumption of soy is very unlikely to benefit you as a man, owing to the simple fact that it is not testosterone friendly. If you are faced with a scenario where soy protein is the only available supplemental form, you should make a hard pass.
Nowadays, there are many effective and superior vegetarian proteins that one can purchase, such as pea protein or even rice protein. The take-home message is to avoid soy and its products like the plague.