The truth about soy is that it’s a food that’s been given a bad reputation by folks with misplaced ideas about how hormones work.
Soy absolutely does not lower testosterone, and the idea that eating something high in phytoestrogens is going to severely affect your hormone levels in any measurable way is just misleading — that’s not how this stuff works.
I want to break this down a bit because, the truth is, soy has so many positive benefits that it’s a little unreasonable to try to paint it as anything other than a healthy food that can be quite beneficial to many people, though not all.
The Truth About Soy — Your Body Breaks Down Soy in a Way That Likely Renders Phytoestrogens Harmless
In fact, it’s possible that phytoestrogens, also called isoflavones, are actually beneficial in low levels.
Most of this debate comes from the fact that phytoestrogens, in a variety of animal studies, have been shown to have detrimental effects in animals.
However, as the authors of the above study state:
“…most of these findings may have little relevance to humans consuming soy food, in particular because the route of administration differs (oral versus injection) resulting in the bypass of the intestines, which provide a limiting barrier to the bioavailability of isoflavones.”
This is the most significant argument against the “soy-as-testosterone-killer” idea. While yes, phytoestrogens could very well be problematic if introduced directly into your body, that’s never going to happen with soy products because you’re not injecting soy (which would be ridiculous): you’re eating it.
That being said, there are still two things to keep in mind here:
- This study is significant because it is a review of a wide variety of studies, rather than a single study that could contain flaws
- The authors admit that caution should still be exercised when exposing women at risk of breast cancer or infants to soy
So, for most people, eating soy products is probably fine. For a section of the population, it may be better to be safe and avoid soy for the moment.
The Truth About Soy — It May Not Be the Healthiest Food in the World, but It Certainly Has Interesting Benefits
While soy isn’t the most healthful food that exists in the world, it certainly has a lot of benefits that recommend its consumption.
Though soy does lack some vitamins and amino acids, it can be an excellent replacement for some of the animal protein in your diet. Unfortunately, eliminating animal protein completely from your diet may not be healthy, but most people eat far too much animal protein, and a reduction could certainly benefit them.
Replacing some of that animal protein with soy protein can potentially have some impressive health benefits.
Here are just a few of the possible benefits of replacing some animal protein with soy protein in your diet (keep in mind that you need about 25g of soy protein a day to really see results):
- Lower total blood cholesterol
- Lower LDL cholesterol (the ‘bad’ cholesterol)
- Higher HDL cholesterol (the ‘good’ cholesterol)
- Reduced blood clot formation
- Lower blood pressure
- Reduced risk of some types of cancer
- Reduced symptoms of menopause
- Reduced bone loss
- Controlled hyperglycemia
- Reduced diabetes
That’s the truth about soy!
Now keep in mind that everything above doesn’t simply happen as a result of eating a bunch of soy, but rather when replacing some parts of your diet with soy protein.
It’s entirely possible that some of the beneficial effects that we’re seeing are not a direct result of the soy itself, but rather are a result of the replacement of other, more problematic sources of protein (namely, certain types of animal protein) with soy.
The Truth About Soy — It Can Benefit Your Health If Approached Carefully
Here’s the truth about soy — it’s not the demon-food it’s made out to be in some circles, but neither is it a magical cure-all as others would have you believe.
The truth about soy, as is the case with most things, falls somewhere in the middle.
To dig a bit deeper into the truth about soy and your proteins, read our article on how soy and testosterone are related.