Soy Sorry: Part 2 – The Research on Soy


While alcohol can make you more feminine, many people think of it as a “manly” substance. Almost the exact opposite is true about soy. People think of soy as feminizing, yet the scientific reality is that consuming normal amounts of soy may do the opposite.

What is soy?

“Soy” is short for soybean. It’s a bean, much like the black beans or pinto beans you eat in your burritos. Or the navy beans in your baked beans. Or the kidney beans in your chili. And like other beans, it’s a great source of protein and fiber. Based on that fact alone, you’d think it should be something men want to seek out, not avoid. (By the way, in England and some other countries, people call soy ‘soya.’ “Soya boya” hasn’t really taken off as an insult there, as far as I can tell.)

Soy is also very versatile in cooking. It has a higher fat content than other beans, and you can cook it in many ways. Some varieties are steamed in the form of edamame. For you low-carb dieters out there, Eden Foods organic black soybeans apparently have only 1 ‘net carb’ per serving. Soy can be turned into tofu, soymilk, cheese, ice cream, yogurt, and countless other items. Tofu, especially when it’s pressed, does a good job of absorbing flavors during cooking. I recommend this BBQ tofu recipe, as an example.

It can be prepared and processed in many ways: soy oil, soy lecithin, soy flour, fermented soy products (like soy sauce, miso, natto, and tempeh). The list goes on.

Soy protein is also often an ingredient in protein supplements and vegan meat products. It’s sometimes an ingredient in non-vegan meat products, too.

Some companies literally use soy protein as an additive to bolster meat.1 In other words, for meat that’s not ‘meaty’ enough, some food companies add soy.

Many of the most popular “bacon bits” brands, like Betty Crocker and McCormick’s, are actually made from soy protein.

Another newsworthy example: the CBC tested Subway chicken and found that it was half soy!2 So much for people who say soy chick’n doesn’t taste like real chicken…

Soybean pods look like ripped, green arm muscles.

Like The Hulk. Look at those things. What could possibly be feminizing about muscular, green, hairy hulk arms?

In addition to being high in protein and fiber, soybeans also contain compounds called phytoestrogens. I know where your mind is going: “Phyto…estrogen? Soy beans have estrogen?!”


As mentioned in part 1, phytoestrogens are not estrogen. Phytoestrogens are compounds that–on a structural, chemical level–are similar to estrogen.

Soy contains ZERO estrogen. None. At all. Zero point zero.

In fact, no plant-based foods contain estrogen.3 If you see a source that states something along the lines of: “soy contains estrogen”–it’s wrong. True estrogen is something that exists in animals (including human men). Not plants or vegetables or beans. (I’ll dig deeper into true, animal estrogen in part 3).

Phytoestrogens, on the other hand, are a broad category of compounds that exist in varying amounts in plant foods. While phytoestrogens are absorbed in the body far more effectively than animal estrogen,4 phyto-estrogens don’t act the same way in the body as estrogen. And ultimately, that’s what matters — how do phytoestrogens affect our bodies and biology?

Phytoestrogens are generally weak and are often anti-estrogenic.

Not weak like uncool. But weak, like, they aren’t strong when it comes to how estrogenic they are.5 In fact, true human/animal estrogen is said to be 10,000 times more potent than both phytoestrogens and industrial xenoestrogens.6

The presence of phytoestrogens leads to decreased circulating levels of free estrogen and reduces the conversion of androgens (like testosterone) into estrogen by blocking aromatase (the enzyme that turns testosterone into estrogen).7 8 A couple of studies found that concentrated genistein can induce aromatase in cancer cells.9 Overall, however, the research shows an inhibitory effect, particularly if you aren’t consuming crazy high levels of phytoestrogens, like from high-dose concentrated phytoestrogen supplements.10

How is it possible that phytoestrogens are capable of being anti-estrogenic? 

One apparent reason: because weak phytoestrogens occupy estrogen receptors in the body, in place of stronger human/animal estrogen. It’s less estrogenic to have estrogen receptor sites occupied by weak phytoestrogens than it is to have them occupied by true, potent estrogen.

Quick background on estrogen receptors in the body: There are two types of estrogen receptors–the estrogen alpha receptor and the estrogen beta receptor. Estrogens may bind to either one, causing them to trigger an estrogenic effect in the body, or sometimes, an anti-estrogenic effect. Different organs and tissues have different amounts of each type of receptor. And each type of receptor may act differently depending on which organ or tissue the receptor is in.11 12 13 14 In breast tissue, the beta receptor is anti-estrogenic, as discussed more below.

Not all phytoestrogens are created equally

Remember the study that found that red wine grapes have anti-estrogenic and pro-testosterone effects? It was due to compounds found in the grapes: resveratrol, proanthocyanidin, and quercetin. All three of those are considered to be phytoestrogens! That’s right, phytoestrogens can make you more like a man.

In fact, there’s a good chance that whenever you hear of some healthy compound in a “super food” fruit, vegetable, nut, bean, grain, or seed–it might be a phytoestrogen.

There are two main kinds of phytoestrogens: isoflavones and lignans.


The phytoestrogens found in soy are called “isoflavones.” The specific isoflavones in soy are almost entirely ‘genistein’ and ‘daidzein.’ They’ve been found to actually block estrogen’s effects in breast tissue.15 That effect apparently has something to do with the fact that both phytoestrogens in soy bind preferentially to the beta estrogen receptor in the chest, which is believed to restrain breast tissue growth.16 17 18 19 Genistein may activate the alpha receptor, but apparently only at crazy high levels that you’d get from consuming high-dose, concentrated isoflavone pills.20 21 Plus, isoflavones, like many other phytoestrogens, are also weak inhibitors of aromatase, especially if they aren’t be consumed in high-dose pills.22 23

This is all pretty huge. In other words, the phytoestrogens in soy may be anti-estrogenic in the breast. The verdict in the case of Soy v. Man Boobs: Not Guilty. Soy has apparently been trying to reduce man boobs all along, yet it’s being accused of the opposite. How unfair.

What can make this topic extra confusing is that, in other parts of the body, soy behaves more estrogenically, rather than anti-estrogenically. One key example is in bones, where estrogen acts to protect and strengthen bones.24 Soy appears to behave more like estrogen (rather than like an anti-estrogen) in bones. Therefore, soy may have a protective effect for people’s bones. This is probably yet another area that men would want to be more estrogenic. Who doesn’t want stronger bones? Soy may deliver that.25


Another common category of phytoestrogens are called lignans, which are found in flax seeds and sesame seeds.26 27 Lignans, like genistein, inhibit the aromatase conversion of testosterone into estrogen, in addition to other anti-estrogenic effects in the breast.28 29 30 I haven’t comes across too many claims about lignans being “feminizing,” but the studies seem to show that they are even less of a concern than soy, and possibly even more anti-estrogenic.

Now, onto the phytoestrogens that are actually feminizing:


Compare isoflavones and lignans to the phytoestrogen 8-PN, which is the phytoestrogen found in hops (and therefore, beer). 8-PN is in a class of its own. It’s been referred to as “the most potent phytoestrogen.”31 Like many other phytoestrogens, 8-PN appears to inhibit aromatase, but that’s only one piece of the puzzle. 8-PN itself is considered extremely estrogenic. Depending on the study, it’s been found to be between 8 to 100 times stronger than genistein and daidzein, the main phytoestrogens in soy.32 33 8-PN is also highly absorbed.34 35 Even more importantly: it binds preferentially to the alpha estrogen receptor in the breast tissue, which promotes the growth of breast tissue.36

(UPDATED 2019: While I originally included these above photos of Simon Cowell for some comedic effect, it’s worth pointing out a few things: Tabloids have made fun of him in the past for having man boobs. As best as I could tell, prior to 2019, he was a beer-drinking, non-vegan. The photo to the right is from 2006. Well, in 2019, Cowell announced that after a lifetime of eating foods like meat and yogurt, he has become a vegan. I’m not sure if Simon still has man boobs. But if he does, you should know the timeline–his man boob days began at least a decade before his vegan days.)

Lavender Oil and Tea Tree Oil

There is ongoing debate about the estrogenic effects about two other common plant-based ingredients: lavender oil and tea tree oil. Neither of these oils are eaten as food (although I sometimes see lavender as an ingredient in teas). They are usually applied to the skin as essential oils, shampoos, soaps, and cosmetics. Since 2007, studies have gone back and forth as to whether these oils cause man boobs or not.37 38 39 The most recent study on this topic that I found (as of 2018) isolated specific phytoestrogens of both lavender and tea tree oil–it found that some of them activated the alpha estrogen receptor, just like the phytoestrogen 8-PN in hops.40 Again, compare that to soy phytoestrogens, which have an affinity for the the anti-estrogenic beta estrogen receptor in breast tissue. As far as I can tell, the phytoestrogens in lavender and tea tree oil aren’t found in relevant quantities in anything that people eat or drink.

How did soy get this reputation? The (weak) case against soy.

Where did the connection between soy and feminization come from? Obviously, a big part is based on the scientific fact that phytoestrogens have a similar chemical structure to estrogen. That alone should rightfully lead to extra attention and investigation. But there’s a lot more to the story than that fact alone.

The Sheep

The study of phytoestrogens dates back to at least the 1950s, when researchers were trying to figure out why some pasture sheep had fertility issues. The sheep were eating tons of this weed called ‘red clover,’ which contains phytoestrogens.

Anti-soy folks often bring up this sheep story as a way to introduce the worries associated with phytoestrogens and soy. There’s one massive problem with the sheep story. The amount of phytoestrogens the sheep were consuming each day by devouring red clover is the equivalent of a human consuming 4,220 cups of soy milk each day!41 In other words, the story has almost no relevance to humans. It’s not possible to consume enough soy foods to get anywhere close to that equivalent amount the sheep were eating.

Coincidentally, as discussed more below, many of the studies that show soy phytoestrogens have any sort of feminizing effect in men involve such absurdly high amounts of phytoestrogens that it’s simply not relevant.

Of Mice and Men

Since the sheep studies first came out, there have been many, many studies and articles on the consumption of soy and its effect on testosterone and true estrogen. Many studies were conducted by feeding massive, concentrated supplements of phytoestrogen to lab mice. Again, these studies are not relevant to humans.

Not to mention, lab mice metabolize soy phytoestrogens differently than humans do, leading researchers to doubt whether these studies have any value.42 On that same topic: plenty of researchers in other areas of science share that doubt–do studies on the effect certain substances have on mice have any relevance to how they affect humans?43 44 45 46 It’s been proven these animals metabolize certain substances differently than humans.

Actual Human Men

But what about human studies? What about studies on men? Virtually every mainstream source, particularly from academic institutions, are consistent in their stance on this topic. It usually goes something like how Oregon State’s Micronutrient Information Center summarizes it: “Exposure to isoflavones . . . has not been shown to affect either the concentrations of estrogen and testosterone, or the quality of sperm and semen. Thorough reviews of the literature found no basis for concern . . .”47 48 Among the mainstream medical and academic resources on gynecomastia, I found one (out of a dozen or so websites with comprehensive gynecomastia overviews) that mentioned soy–and the one source that mentioned it only refers to it in the context of eating massive amounts of soy every day.49

In the past 20 years or so, there have been a bunch of studies on soy intake and how it affects actual human men. I promised to be comprehensive — I think I’ve got all the big studies, but if I’m missing one, let me know.

The vast majority of studies on human men have shown that soy has no effect on estrogen, testosterone, fertility, sperm count, or sperm quality.50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73

At least one study showed that soy decreases estrogen.74

The lead author of the most recent study on soy that I found even sent out a tweet even sent out a tweet when the results were published–the tweet used the hashtags #nogynecomastia #fearnot.75 Let’s get those hashtags trending!

That’s a lot of studies that show that soy does not increase estrogen, decrease testosterone, and/or cause feminization of men. But this massive amount of studies gets overlooked for the eight or nine “negative” ones. Let’s look at each of those negative studies.

The Negative Human Studies

Those who argue that soy is feminizing tend to cherry pick the eight or nine human studies that don’t quite line up with the overwhelming majority that show that soy has no effect on testosterone or feminization of men. (Speaking of cherries and animal testing–cherries are loaded with something called anthocyanin, which is a phytoestrogen that’s been shown to increase testosterone in rabbits.76 Fun fact.)

These negative studies all seem to have some glaring flaw with them. Or, whatever impact they found that soy had, was very minor or very nuanced. In a couple cases, the researchers re-did a similar study later on, with opposite results. Here are those studies (I really tried to identify all of them from the past 20 years).

Soy eaters have more ejaculate study.77 In the late 2000s, this study got cited as evidence that soy is feminizing, yet it found that soy had no effect on sperm motility or sperm morphology. What it did find is that soy intake was associated with lower sperm count. However, look at the different test groups: the study involved 99 male patients at a fertility clinic. These fertility clinic patients filled out a questionnaire asking how much soy they ate. 39 men consumed none; 18 consumed between 0.01 and 0.07 servings of soy per day; 22 consumed between 0.08 and 0.29 servings of soy per day; and 20 consumed 0.3 or more servings of soy per day. These servings are tiny. For that reason alone, this study is almost certainly irrelevant! If anything, it should be reassuring. Think about it: 99 men were patients at a fertility clinic (these men had fertility issues!) and they basically consumed no soy! Another interesting thing about the study is that the more soy people reported eating, the more ejaculate they had. How manly is that? Unfortunately, that part of the story didn’t make the headlines. Other researchers have theorized that the increased ejaculate amount explains the slightly lower sperm count. In other words, there wasn’t less sperm, but there was more ejaculate, and therefore less sperm per milliliter of ejaculate.

Eating the equivalent of 36 servings of soy study.78 This supposedly anti-soy study involved men with prostate cancer receiving supplements that contained either the amount of phytoestrogens found in the equivalent of 18 servings worth of soy; or an even more absurd amount found in the equivalent 36 servings worth of soy. Two of guys in the even-more-absurd 36 serving group reported breast growth. One of them was taking a drug associated with breast growth. To keep things in perspective, one serving of soy is, for example, 1 cup of soymilk. So this would be like drinking 36 cups of soy milk each day. I’m pretty sure many of these men would have died by cup 20 or 25, considering even humans are thought to have died from drinking 25 cups of water in a single span.79 In other words, this study on concentrated soy supplements is irrelevant to you, unless for some reason you want to take an absurdly high isoflavone supplement. No one in the the 18-serving group had this effect, I think that’s very reassuring, considering 18 servings is also an absurdly high amount.

DHT study.80 This study showed that soy had a minor decrease on DHT. Three things about this study: First, DHT is a hormone that gets converted from testosterone. But it’s arguably a hormone that men want to be lower. DHT’s most infamous effects on men are believed to be hair loss and prostate enlargement.81 While this study gets cited as soy being anti-testosterone, it’s apparently only anti-DHT, aka the (apparently) “bad” form of testosterone. To be fair to DHT, it is a potent testosterone. So, it’s not uncommon to see fitness guru types defend DHT, because of its supposedly powerful effects on things like muscle growth and keeping fat off. But studies appear to show that having lower amounts of DHT doesn’t even negatively affect those things.82 At least one other study has shown soy decreases DHT, but not total testosterone.83 And another study found the opposite result when studying concentrated genistein: DHT increased.84 Weird. Second thing about this study: soy didn’t impact other (non-DHT) testosterone levels. It only had the effect of reducing DHT. Third, the study compared groups that consumed one of two forms of soy protein, one group consumer soy with phytoestrogens, and one group consumed soy with phytoestrogens removed. The effect soy had on DHT was the same, regardless of whether it had phytoestrogens. Oddly, the soy without phytoestrogens had a minor increase in estrogen levels. I’m not sure what to make of that—but this seemingly goes against almost every other study about soy and phytoestrogens. The thing about soy that people fear is the phytoestrogens, yet it didn’t matter whether soy had phytoestrogens or not. Very weird.

The scone study.85 This study involved men consuming scones made of either wheat flour or soy flour. Among the soy group, there was no change in estrogen, but there was a minor decrease in testosterone, from 19.3 nmol/l to 18.2 nmol/l. This study has been criticized because, somehow, the researchers didn’t test the control wheat group–no baseline or final levels were taken.86

The early Japanese study.87 This study was based on a questionnaire and found that men who reported eating more soy had slightly more estrogen and slightly less testosterone. The authors noted the correlations were only of “borderline significance.” The same researchers then put this questionnaire to the test by having men consume either soy milk or a placebo for 8 weeks. The results: testosterone levels did not change, and estrogen levels actually fell!88

The butter study.89 This study compared people who ate meat, and people who ate a meal of soy, butter, and animal lard. There were no differences in average serum testosterone or estrogen levels, but the soy group had a lesser ratio of testosterone to estrogen. The changes here were minor. The study has been criticized for having potential confounders.90 Maybe the fact the soy group also ate butter and animal lard limits this study’s impact?

The outlier study.91 The headline conclusion of this study is that soy protein decreases serum testosterone levels in men. But if you look at the results, it’s unclear how this study even got published. Of the 12 men who were studied, all but one of the participants’ levels went unchanged! In fact, one of the participants started out slightly below the healthy testosterone range, and then, after consuming a bunch of soy, had testosterone levels return to the normal, healthy range. For the others, they were all relatively consistent, with no change in testosterone. Except for one guy–the “outlier”–whose day one levels of testosterone (before he ever consumed any extra soy for this study) were absurdly high, beyond the normal healthy range. He had unhealthfully high testosterone, which had nowhere to go but way, way down. Indeed, his absurdly high levels came down to the normal healthy levels, and stayed there for the remainder of the study. This study has been criticized for having such a small sample size, and for being published at all, despite the absurd outlier guy, who skewed the results.

The 2007 pee study.92 This study showed that people who consume soy pee out more estrogen. For the vast majority of studies that make claims about soy and testosterone and estrogen levels, the researchers studied blood serum levels of those hormones, not urine levels. This study, however, tested urine levels. And it found higher levels of estrogen in urine. As mentioned in Part 1, does this mean the body produced more estrogen, or does it mean that the body had the same level of estrogen, but simply peed out more of it? Remember that compound in red wine grapes that is supposedly pro-testosterone? The reason researchers believe that is because it causes men to pee out less testosterone. Using that same logic, the compounds in soy could be anti-estrogenic because they cause men to pee out more estrogen. The authors of this article had that same thought: “. . . increased urinary [estrogen] excretion over time could decrease systemic [estrogen] exposure.” In any event, a study a few years later found that the more soy boys consumed, the less estrogen they excrete in their urine.93 Suffice it to say, this is a confusing topic.

That same year, those same authors came out with a study that showed that soy “suppresses androgen expression” in the prostate.94 Testosterone is an androgen, so “suppressing androgens” sounds like one thing you want to avoid. Except, this study looked at suppressing androgen in prostate tissue, which is seen as a beneficial thing, because androgens enlarge the prostate. The authors also noted that there was no change in testosterone levels (even DHT) or estrogen. However, there is an exception: they also studied soy that had the phytoestrogens removed, and like the 2005 DHT study, this study showed that soy without isoflavones increased estrogen levels. Again, I have no idea what that means and I’ve found no good explanation for that. Very weird.

In any event, this same group of researchers authored a meta-study a couple years later in 2009 and, after looking at all of the soy/testosterone studies to date, including their own studies, they found that soy did not reduce testosterone.95

2013 weightlifting study.96 Participants here ate either soy protein, whey protein, or a placebo, for 14 days. Their estrogen and testosterone levels went unchanged. On the fifteenth day, they took one last dose of their respective protein, then they hit the gym. Quick note: when people lift weights, their testosterone levels increase during and after the weightlifting, and then those levels gradually fall back to their normal levels. That happened here for all three groups, including the soy group. With one nuanced exception: after the increase in testosterone from lifting weights, the soy group’s levels returned to the normal levels faster than the whey or placebo groups. In other words, that temporary increase in testosterone that weight-lifting causes–there’s something in soy that may shorten the length of that increase by about 45 minutes or so. The researchers behind that study admitted that the result was surprising, given that so many other studies have shown no effect on soy and testosterone levels. Yet this study is still essentially consistent with those other studies. Soy didn’t affect testosterone levels, other than in this temporary, limited, 45 minute circumstance. Beginning and ending testosterone levels were all the same. So, eating significant amounts of soy protein every morning for 2 weeks and right before a workout didn’t result in lower testosterone.

Is 45 minutes less of elevated testosterone worth freaking out over? After all, there is research that shows that soy protein is on par with whey protein in terms of muscle gain from resistance retaining.97

That’s it. When it comes to studies on men and the alleged feminizing effects of soy, those are the negative studies that I found. They are all either flawed, misunderstood, or found such a minor, nuanced effect that it shouldn’t cause concern. All the mainstream medical sources that summarize the evidence on soy have basically the same conclusion: there is no concern about soy foods causing feminization among men.98 99

The Two OG Soyboys

In the world of science research, the strongest forms of evidence include things like meta-analyses, like the 2009 and 2016 meta-analyses that found that soy intake does not alter testosterone levels in men.100 101 Among the least reliable forms of evidence, however, are case reports.102 A case report is a report on an individual participant or patient.

Nevertheless, the case against soy relies heavily on two isolated case reports. One involving a 60-year-old dude in 2008, and another involving a 19-year-old guy in 2011. These two soyboys are the president and vice president of the ‘soy feminizes men’ world. Anti-soy crusaders usually start their presentation with the sheep story, and then shove these two fellas onto the main stage. Gentlemen, meet the original soyboys:

The 60-year-old dude.103

Here’s the gist of the case report (which, for what it’s worth, the authors called an “unusual” case of gynecomastia): 60-year-old dude gets man boobs. Doctor finds dude’s estrogen levels to be very high. Dude says he began doing two new things in his diet somewhat recently: He became obsessed with a product called Ensure. And he began drinking 12 cups of a soy milk each day. His doctors told him to stop drinking all of the soy milk. He replaces soy milk in his diet with lactose-free dairy milk. Did his man boobs go away? Nope. His estrogen levels dipped, but then crept back up, despite no longer consuming soy milk. Then his doctors realized that Ensure contains soy protein, so they tell him to stop drinking that, too. So he does. Did his man boobs go away? Still no, though he reports them as being less tender and his estrogen levels returned to normal.

This story is often Exhibit A for those who fear that soy causes moobs. It gained a lot of notoriety because Men’s Health wrote an in-depth article about the 60-year-old dude in 2009 that they titled “Is This the Most Dangerous Food For Men?”104 Talk about clickbait. How did an “unusual” case of gynecomastia become their main argument against soy? When you look into the details of this report, many things don’t add up.

First (as mentioned in Part 1) every source about gynecomastia says gyno is very common among men above the age 50, regardless of their diet. Some sources say up to 70% of men in their 50s and 60s have some degree of gynecomastia.105 This is just something that happens to the vast majority of men when they age regardless of what they eat or drink. This dude was 60 years old. Isn’t it possible his age played a big role in his inexplicable breast growth? Sneak into a local retirement community–there are moderate cases of man boobs everywhere, yet no soy to be found at the snack bar.

Second, can we take a minute to acknowledge how much soy milk this guy was consuming — 12 cups a day?! That’s an insane amount. Not quite 1950s sheep levels, but still pretty absurd.

Last thing about the 60-year-old dude. When he quit the absurdly high 12 cups of soy milk per day, it didn’t ultimately fix any of his issues. It’s only after he quit drinking the product Ensure that his estrogen levels went down (his other issues, including man boobs, remained). Yet soy still gets the blame. But look at Ensure’s ingredients. Soy protein is the sixth most predominant ingredient. What’s the fourth most predominant ingredient? “Milk Protein Concentrate.” In summary: this man stopped consuming soy milk, but his man boobs grew while he was gulping down lactose-free cow’s milk and milk protein concentrate with Ensure. Cow’s milk contains true estrogen. Any chance that was the cause? (I’ll delve more into cow’s milk in part 3.) What’s even crazier: the phytoestrogen content of Ensure has been established. There is not very much phytoestrogen in it–only 4 mg per every 100 g of Ensure.106 To put that into perspective, a Jack In The Box beef taco has 15 mg of phytoestrogens per every 100 g.107 But you don’t see the same level of controversy for Jack in the Box’s “beef.” The evidence here raises more questions than answers.

The 19-year-old guy.108

A couple years after the 60-year-old dude’s case report was published, this 19-year-old guy shows up to his doctor’s office saying he lost his sex drive. The doctors find that his testosterone levels are very low. He’s got type-1 diabetes and had been eating 14 servings of soy each day. They tell him to stop eating soy. A year later, his testosterone levels and sex drive came back to normal. Yet again, the evidence is too whack to turn this story into an anti-soy story.

First of all, it’s worth mentioning this guy didn’t have man boobs, despite his 14-servings of soy per day. Sometimes this story is coupled with the the 60-year-old dude as evidence that soy causes moobs. But gyno wasn’t one of his symptoms. His issues were low testosterone and loss of his sex drive.

Second, he was a Type-1 diabetic. That’s a condition that’s associated with low testosterone,109 and loss of sex drive!110 Type-1 diabetes is also associated with gyno among men111–but again, he didn’t have man boobs.

Lastly, if you thought the 60-year-old dude was consuming a lot of soy at 12 servings per day, the 19-year-old guy was consuming the equivalent of 14 servings per day! Imagine consuming 14 servings of the same type food, and doing that every single day. Even if soy did cause any of his issues, he was eating absurdly massive amounts of it.

These two guys seem like pretty awful figureheads for the anti-soy argument, yet that’s who they’ve got.

The fact they each were consuming 12 to 14 servings of soy each day raises a question:

What is a “serving” of soy, anyways?

Here’s a nice guide for classifying what a food scientists mean when they refer to a single “serving” of soy. It’s either 1 cup of soymilk; 8 to 10 grams of soy protein; or 1/2 cup of tofu, tempeh, soy meats, or soybeans.

The 8 to 10 grams of protein is pretty spot on. 1 cup of soy milk has 8 grams of protein. Half a cup of tofu has 10 grams of protein. Half a cup of tempeh has 15 grams of protein. It’s all roughly in the same protein range.

To add some context, the NIH recommends adult men consume 56 grams of protein per day.112 And the USDA’s recommended serving of “high protein foods” is 5.5 ounces per day, either in the form of meat, eggs, beans, nuts, or seeds.113

So, if you’re a man, and you’re following the USDA and NIH reference figures, and you’re fulfilling your high-protein food quota with soy, you’d be eating 5.5 ounces, which is about two servings per day.

The 60-year-old dude was consuming about six times that amount. The 19-year-old guy was eating even more than that. Who are these people?! These guys were consuming absurd amounts of soy.

However, if we give some credit to the sheep, the 19-year-old, and the 60-year-old, all this seems to teach us is something we all already know: Maybe you can consume too much of anything and have negative health effects. People have gotten very ill from drinking too much water.114 You could eat too much spinach and get sick.115 Spinach! Is nothing sacred? Popeye would have been screwed.

Even if soy truly did cause the issues of these two soy OGs, we’re talking such massive, almost unimaginable amounts of soy that barely anyone could relate to. I love soy products, and I, admittedly, have very little self control when it comes to vegan ice cream and vegan chicken nuggets. Yet, even if I gave embarked on the most ultimate cheat day ever, I don’t even think I could get to 12 servings a day, let alone doing that every single day, like the 19-year-old and 60-year-old did. Even if you binged on soy, to match their insane intake. you would have to eat 3 or 4 entire blocks of tofu. Every. Single. Day. Or 12 vegan hot dogs, per day.

Actually, it’s more like 24 vegan hotdogs per day. Why 24 hot dogs? Because nowadays, many vegan meats either don’t have any soy at all, or they are a mix of soy and other proteins. Which brings us to the next section…

Vegan Meats Today

“Soy meat” has become an obsolete term. If you can’t shake the myth that soy is feminizing, don’t group other high-protein vegan foods in there. Sure, many restaurants still often serve tofu as their ‘vegan’ protein option. But food companies have discovered many new ways to prepare plant-based proteins. More and more products are emerging that either have only some soy, or no soy at all. In fact, some of the best vegan meat products don’t use soy protein. The protein in Beyond Meat burgers and sausages is entirely from peas.116 Field Roast products are made from wheat protein.117 Even my favorite Tofurky products (the deli slices, the slow roasted chik’n, the sausages, the holiday roasts, and the hot dogs) are mostly wheat protein!118 They have “tofu” in the name, yet more than half of the protein is from wheat protein. The Just Egg, which is a brand new vegan egg scramble, is made from mung bean protein.119

This begs the question: do these other vegan sources of protein (pea, wheat, mung bean) have phytoestrogens? Nope. They don’t.120 Not in any significant amounts, at least. Check out the USDA database of this information if you’re curious. Peas either have none, or almost none. Mung beans have almost none. Wheat protein (aka seitan) appears to have none. The same goes for almost all other foods high protein vegan foods. Virtually all other beans, other than soy, barely have any. Garbanzo beans and fava beans have a bit more than zero, but not by much. Nuts and seeds, other than flax and sesame, barely have any. Grains barely have any.

Sometimes I come across articles and blogs that say something like “Phytoestrogens are found in . . .” and then the blog proceeds to list almost every single food, including beans, grains, and animal products like meat and dairy (more on them in part 3). Technically, that might be true — there are probably tiny, tiny amounts of phytoestrogens in everything — but it’s such a small, irrelevant amount. There’s a very good chance you have cocaine in your pocket right now. That’s because at least 80% of dollar bills have cocaine on them.121 It’s such a tiny, insignificant amount of cocaine that you don’t need to mention it on a drug test. Same goes for the extremely small amount of phytoestrogens that are in nearly every food.

Soy Panic?

But what about the food products that actually have soy in them? A lot of anti-soy stories revolve around the idea that “SOY IS IN EVERYTHING!” 

Soy is a common ingredient in lots of things, especially processed foods. That much is true. But, shockingly, the specific soy products that are in “everything” either have no phytoestrogen or almost no phytoestrogen. I’m specifically talking about soy oil, soy sauce, and soy lecithin.

Soy oil has NO phytoestrogens.122 Zero point zero. Soy sauce has almost no phytoestrogens.123 Soy lecithin has barely any phytoestrogens, especially when you consider it’s only used in very small amounts as an ingredient in foods.124 If you consume these ingredients regularly, the amount of phytoestrogens in them is basically statistically irrelevant.

Soy protein concentrate is another common ingredient, and it might have very little phytoestrogen. It turns out there are two main ways food companies produce soy protein concentrate. One method is called the ethanol wash process, which reduces the phytoestrogen content by nearly 90%.125 The other method (called the “aqueous wash” method) doesn’t have that effect. I tried to find out which companies use which method, but I came up empty. The customer service rep I emailed from Gardein had absolutely no idea what I was talking about. I have a feeling Ensure (which the 60-year-old case report dude drank, and which contains soy protein concentrate) might use the ethanol process on their soy protein concentrate, considering Ensure has relatively low amounts of phytoestrogens.126 Remember: the 60-year-old would consume more phytoestrogens by eating a beef taco from Jack In The Box than from drinking Ensure.

All in all, the soy ingredients that sneak their into “everything” don’t even have phytoestrogens.

For animal products, it’s a different story. Read on.

Click here for SOY SORRY – PART 3: Meat, dairy, and how being vegan can make you more manly.

The content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.


  2. Subway
  5. EHormone 2
  6. Human Reproduction Journal
  127. None of this content is medical advice.

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