SOY SORRY – PART 4: Hormones in meat and milk + can veganism make you more manly?
The overarching medical and scientific understanding of soy is that it does not cause feminization or man boobs in men (read part 3 for the evidence on that). But what effects do animal products have on those issues? It turns out, animal products have all three categories of estrogen: true animal estrogen; industrial xenoestrogens; and plant phytoestrogens.
Hormones in Animal Products
Phytoestrogens in meat, eggs, and dairy
Animal products have small amounts of phytoestrogens. That makes sense–especially considering a lot of livestock are fed crops that have phytoestrogens, like soy. 70% of the soy that’s grown in the US is used for livestock feed.1
Some animal products contain more phytoestrogens than some plant-based vegan foods. Of all animal products, milk, dairy, and eggs tend to have the highest amounts of phytoestrogens.2 Meanwhile, foods like potatoes and soy oil, contain virtually no phytoestrogens. So if you truly want to avoid phytoestrogens, apparently your best bet is to replace meat with french fries cooked in soy oil.
Industrial xenoestrogens in meat, eggs, and dairy
As mentioned in part 2, meat, fish and dairy products tend to be the biggest source (or one of the biggest sources) of human exposure to a huge array of industrial xenoestrogens–especially phthalates, dioxins, alkylphenols, PCBs, heterocyclic amines, and polycyclic hydrocarbons.
When you read about many of these industrial xenoestrogens, you’ll often find that they “work their way up the food chain” or that they “bioaccumulate.” That almost always means that animal fat (or “lipids”) do a really good job of harboring many of these various xenoestrogens. Pesticides, for example, are sprayed on animal feed crops, which are then consumed by livestock, and then dissolve into animal fat.3 Evan local, organic foods have these issues.4
Dioxins: Meat, dairy, eggs, poultry and fish supply at least 75% of dioxins in the human diet.5
Phtalates: Meat, poultry, cream, and oils like butter and lard are the foods with the most.6
BPA, where the biggest dietary sources are canned food, and among non-canned food: meat and fish products.11
If you want to avoid industrial xenoestrogens, replacing meat, dairy and fish products is apparently a good place to start.
True estrogen in meat and dairy
Animals contain actual estrogen. Unlike soy and other vegan foods, which contain none. As discussed in part 2, even human men have true estrogen.
In fact, all vertebrate animals have estrogen–including all the ones people eat for food.17 Men, along with cows and deer and ducks and rabbits and lambs and goats and buffalo and chickens and pigs, all naturally have estrogen coursing through their flesh and veins. The females of each of those species have a lot of estrogen in their eggs and milk. This means if you consume animal products, you are consuming actual estrogen. Milk and dairy products contribute the most (60% to 80%) estrogen to a person’s diet. Eggs contribute about 10% to 20%. And meat and fish contribute 10% to 20%.18
A healthy liver (ie, one that hasn’t been compromised by long-term or excessive drinking) and digestive system eliminates about 90% or so of estrogen before it can get absorbed into the blood and tissue.19 Because of that, most reputable health and medical sources historically haven’t been too concerned about the effects estrogen in animal products have on humans. But that may be changing.
What about the 10% or so of estrogen that the liver and digestive system doesn’t filter out? Given that true animal estrogen is hundreds to thousands times more potent than phytoestrogens,20 21 if some, even tiny amount, of true animal estrogen is slipping its way through the digestive system, and being absorbed by the body, and then binding to the alpha estrogen receptors, couldn’t animal products be having a feminizing effect on men? These might be small amounts of hormones that aren’t easily detected in blood tests, but still have a powerful feminizing impact.
In one report, researchers criticized major health organizations for not taking seriously the impact that the true hormones in meat can have. In their words: “. . . the safety of hormone residues in meat seem to be based on uncertain assumptions and inadequate scientific data . . . The possible biological significance of very low levels of estradiol is neglected . . .”22
This begs the question: do the estrogens in animal products actually have an effect on people?
A special shoutout to milk
I started this blog post off with the story of how I discovered soy milk. I needed something to replace cow’s milk in my diet after I learned that dairy products might be causing my acne breakouts. So I replaced dairy milk with soy milk. My breakouts stopped. As I mentioned in part 1, There are a lot of studies that show this connection between dairy and acne.23 24 25 26 27 28 29 30 31 32
The exact mechanism of how milk might cause acne is subject to debate. One of the leading theories is that it’s the hormones in milk that cause acne.33 Not the hormones that are sometimes added by dairy companies to milk, but the hormones that milk naturally contains. If you think about what milk even is, that makes sense. Milk is a liquid secreted by the mammary glands of female animals to feed their young immediately after birth.34 Milk is basically a creamy cocktail of female sex hormones produced by lactating cows. These hormones include estrogen, progesterone, prolactin, and IGF-1.35 36 Milk is the leading source of true estrogen in the diet.37
Again–these hormones all occur naturally in milk. Don’t get confused by the companies that market their products as having “no added hormones.” When milk or meat companies make that claim, they are talking about added growth hormones (rBGH and rBST), which are used to increase the cow’s milk production.38 That claim has nothing to do with the actual estrogen, progesterone, prolactin, and IGF-1 that these products naturally contain. In the recent past, several milk companies marketed themselves as having “No Hormones,” but the FDA put a stop to that because all milk contains naturally occurring hormones.39 These companies are only allowed to make the claim about milk having no added hormones. The bottom line: Milk (whether conventional milk or free-range, raw, organic, grass-fed milk) contains natural female hormones.
Whether human babies should be consuming cow’s milk is one thing. What I’m interested in is whether anyone older than the age of ‘baby’ should be consuming this stuff. Especially men. What effects does cow’s milk have on people? To be fair to milk, I haven’t seen a major medical source implicate it with the specific condition of man boobs, as much as that would make sense, considering it contains all of the hormones that are believed to cause gyno. However, there have been plenty of studies that connect milk with other feminizing or estrogenic effects.
In 2010, a study found that men absorbed the estrogen in milk, their estrogen levels increased, their progesterone levels increased, and their testosterone levels decreased.40
One review of the research on acne summarized the concern about dairy like this: “. . . drinking milk and consuming dairy products from pregnant cows exposes us to the hormones produced by the cows’ pregnancy, hormones that we were not designed to consume during our teenage and adult years . . .”41 Another review put it like this: “[I]t seems that steroid hormones are very potent compounds in dairy foods, which exerting profound biological effects in animals and humans . . . recently it is found that these compounds even at very low doses may have significant biological effects . . .”42
So, only a tiny amount of estrogen may slip through the liver’s filtering process, but that tiny amount is so potent that it might have a significant effect.
Some researchers believe that the high estrogen and/or progesterone content in the milk may be responsible for promoting the growth of mammary tumors and cancer, among other adverse effects.43 44 45 Other studies have connected dairy food consumption with damage to the testicles and sperm, due to the hormones in milk.46 47 48
Can veganism make you more manly?
If you’ve read this far, you’re probably interested in what sorts food and lifestyle choices you can make to become more manly, at least on a biological and hormonal level. In other words, what choices increase testosterone or reduce estrogen? The answer to this question might make you rethink vegan stereotypes.
First of all, what do legitimate medical experts say helps increase testosterone? Most legitimate medical experts seem to be hesitant to make claims about a specific food or activity. In most cases, the evidence is weak. Or the impact on your testosterone is temporary, and doesn’t truly improve long-term levels. When it comes to real, long-term improvements in testosterone levels, they all basically say the same thing:49
1) Get plenty of sleep.
2) Exercise consistently, but not too strenuously.
3) Don’t be overweight.
4) Reduce stress.
These might seem like the most obvious healthy habits a person could have, but we shouldn’t take them for granted. They happen to be some of the only lifestyle choices that can legitimately increase your long-term testosterone levels. In the world of food, there are a few choices that mainstream experts do mention regularly:
Zinc, Magnesium, and Vitamin D. Don’t be deficient in Vitamin D, magnesium or zinc.50 Whether you’re vegan or not, these are nutrients that aren’t found in significant quantities in too many common foods.
Magnesium is mainly found in nuts, seeds, avocados, potatoes, spinach, grains, and soy milk, among other foods. Basically no animal products are a great source of magnesium.
Zinc is mainly found in either supplements, beans, fortified cereals, pumpkin seeds, and oysters. Vitamin D is mainly found in either either supplements, fortified cereals, fortified orange juice, and fortified non-dairy milks.
With the exception of egg yolks (not egg whites), some fatty fish species, organ meats, and certain cuts of beef, there aren’t too many animal products with significant amounts of Vitamin D or zinc. Milk has some Vitamin D, but only because milk producers mix in a Vitamin D supplement to the final product. (Seriously, check the label of your milk. ‘Milk’ probably isn’t the only ingredient.)
You’ll often see blogs name any number of these foods as being pro-testosterone. It’s not for some magical, manly reason, but rather because those foods have these crucial nutrients. But unlike the vegan products and supplements, consider that meat, dairy, and fish are the biggest dietary exposure to a broad range of industrial xenoestrogens, especially the fattier animal products — I’m not sure animal products should feature prominently on any pro-testosterone guide.
Dietary fiber. Fiber is only found in vegan foods. No meat, egg, dairy, or seafood products have fiber. Yet fiber intake is connected with lower estrogen levels, thanks to fiber’s impact on several bodily process. One recent study summarized the biology behind it: fiber reduces the recycling of estrogens; it decreases an enzyme that allows estrogens to re-enter the bloodstream; and it binds to estrogen, which increases excretion (fancy word for poop) of estrogens.51
Confusingly, fiber is also associated with higher SHBG levels.52 As mentioned in part 2, SHBG binds to testosterone, and (to a lesser extent) estrogen. So, fiber apparently makes testosterone (and estrogen) less bioavailable by raising SHBG levels.
So are low levels of SHBG something you want? This is about to get a lot more confusing.
SHGB aka the sex hormone binding globulin. Low levels of SHBG should mean more bioavailable testosterone. Yet low SHBG levels are a risk factor for heart disease, diabetes, and certain types of cancer.53 For what it’s worth, typically fitness bloggers are some of the only people I see who explicitly recommend that people aim for lower SHBG levels.
Many healthy habits appear to increase SHBG. Exercise, for example, exercise increases testosterone. But it also increases SHBG.54 (Confusing, fitness bloggers love exercise, which raises SHBG, but they also recommend having lower SHBG). Same with Vitamin D, it’s associated with more testosterone and more SHBG.55 56 Low glycemic diets are linked to higher levels.57
High-sugar diets are linked to lower SHBG levels.58 High protein and high-carb diets are linked with lower levels of SHBG.59 Magnesium is associated with lower levels of SHBG.60 But confusingly, the best sources of magnesium are high-fiber plant-based foods, as discussed above.
What’s the takeaway here? I have no idea. Too many well-established healthy habits, like exercise and eating fiber, increase SHBG. And too many of our biggest killers are associated with low SHBG. That potentially means less bioavailable testosterone. If you’re searching for perfection in diet, you aren’t going to find it.
Certain phytoestrogens, fruits, and vegetables. As mentioned in part 3, consuming moderate amounts of a bunch of phytoestrogens (consuming the foods that those phytoestrogens are found in) are linked with either lowering estrogen or increasing testosterone.
Indole-3-carbinol has been shown to be anti-estrogenic.61 It’s found in cruciferous vegetables like broccoli, cauliflower, kale, cabbage, Brussels sprouts, among others.
Mushrooms have been shown to have potent anti-aromatase activity.62
Proanthocyanidin, quercitin, and reservatrol. As mentioned in part 2, there’s some evidence that consuming foods with these compounds have varying degrees of either anti-estrogenic or pro-testosterone activity. Some varieties of grapes, berries, onions, and other foods contain these compounds.
The list of potentially anti-estrogenic and/or pro-testosterone could go on, but I need to stop somewhere.
What about soy?
Some medical sources specifically recommend soy (and flax) to decrease estrogen, apparently based on the theory that the phytoestrogens in them are largely anti-estrogenic, particularly in normal quantities.63 Looking at the research on soy and its impact on estrogen and testosterone, it seems like regularly eating normal amounts of soy food (say, 2 to 5 servings per day, rather than the absurd 14 to 36 servings per day) can give men the anti-estrogenic de-feminizing benefits of soy, without going anywhere near the various studies and case reports that show massive amounts of soy might start to have the opposite effect.
Putting it all together, these anti-estrogen and pro-testosterone dietary choices are very vegan friendly.
Eat more fiber because it lowers estrogen levels. Eat more mushrooms, certain fruits, and cruciferous veggies because they contain compounds that may be anti-estrogenic or pro-testosterone. If you’re not getting enough Vitamin D, magnesium, and zinc, then look into supplements. Avoid dairy, eggs, and fatty meats and fish because those foods tend to have the most actual estrogen and industrial xenoestrogens.
Put all that together, you might be seen as the least fun person at your next family barbecue. But you might also become the most manly.
Why you should want others to be vegan
Putting aside the fact that animal products are such a significant source of industrial xenoestrogens and actual estrogens in your own diet–animal products are also the main source of estrogen in the world, period. (No pun intended). Thanks to their poop and urine, livestock in the US and Europe discharge 182,000 pounds of estrogen per year into the world. In comparison, all 7 billion humans in the entire world discharge about a third of that: 66,000 pounds of estrogen.64
Whether it’s factory farming (where unmanageable amounts of animal excrement are concentrated together) or organic farming (where huge amounts of animal excrement are applied to crops), it all contributes to more estrogen in the environment.65 Much of the estrogen ends up in drinking water.66
If you want there to be less estrogen in our water and environment, you should want there to be less livestock farming. The only way to achieve that is for people to stop buying meat and dairy products.
I started this article off with a bunch of common myths that many adults still believe to this day. Which is understandable. You can’t blame people for mistakenly believing that MSG is bad for you. It’s something not many people have actually looked into. I sure didn’t know about it. The truth involves a lot more nuance.67 If I see a product or restaurant advertise “No MSG,” my mind then decides that MSG must be bad. Even though there’s no almost no logical or scientific reason to think that.
The same goes for the intricacies of phytoestrogens and man boobs. Who has the time to know all of this stuff?
The good news, things are changing. Men’s Health, which infamously had a very popular anti-soy article 10 years ago, now seems to be publishing pro-soy articles. More and more news stories seem to be dedicated to dispelling the anti-soy myths.68 69 70 71
The truth about soy is kind of boring: it’s a solid source of protein. That should be enough to know, unless you’re eating absurd amounts of it. So what’s keeping this simple truth from being more accepted by men?
The fear of soy strikes hard and deep for men.
My personal view, after years and years of thinking and reading about this stuff: Many men are very occupied with appearing physically masculine. That includes having a ripped chest. It’s one of the easiest-to-see examples of how ‘masculine’ a guy is. The fact that soy is rumored to detract from manliness makes the fear very powerful. Soy is avoidable, so why not avoid it, if there’s some chance?
What this completely ignores is the context. Feminization of men happens just because. So many men–a vast majority–deal with issues regarding their chest appearing flabby or puffy. Testosterone production decreases with age. Medications, drugs, diseases, and body fat are all considered major causes of moobs. Man boobs can emerge in puberty and never go away. Even if you’re in your 20s or 30s, there’s a decent change you have (or had) a couple of centimeters of “asymptomatic” gynecomastia–just because that’s what happens regardless of what you eat or drink.
How the fear of soy is spread
There is an absurd amount of misinformation out there about soy, especially among a few anti-soy fitness bloggers and youtubers; and among quacky pseudo-science websites. Why are they all so anti-soy?
Your whacky aunt. Think of all the quacky things your whacky aunt posts about on Facebook each day. There’s a good chance her sources overlap with a certain organization (whose name I won’t include because why give them extra Internet points?). This organization publishes more anti-soy blog posts than any other source. This review summarizes what this organization is all about. Basically, they are one of better-known pseudo-science websites that publish quacky homeopathic health advice. They are anti-vaccine; anti-fluoride; pro-raw milk; pro-eating-dandelion-extract-to-detox-your-body. They also happen to hate soy. Why do all these sorts of things always seem to go together? Why can’t the whacky aunt be all those things and at least be anti-raw milk? Maybe there’s something appealing about feeling like you know something that everyone else doesn’t. Again, the truth is often a lot more boring than that.
The meat industry’s role. The big meat, egg, and dairy companies, and their more secretive industry groups, spend tons and tons of resources to keep people eating meat.72 73 74 75 76 If there is something that’s not explicitly against the law that might help them maintain their monopolies on our diets, then they will explore it, especially if it’s a hidden battle. Influencing governmental dietary guidelines. Lobbying to make it a criminal act to film inside farms. Misinformation campaigns about vegan alternatives. You name it, the meat and dairy industries have probably tried it.
I strongly suspect that promoting anti-soy articles and videos is part of their plan. “Hey fitness blogger with 500,000 followers on social media. Want $2,000? Just sign this non-disclosure agreement and post a YouTube video that soy causes manboobs. Here’s a case report of a 60-year-old dude who had manboobs, and it might be from soy. Mention that.”
Before you group me in with your whacky aunt and accuse me of being a tin-foil conspiracy theorist–I should clarify–this practice has already been revealed in similar contexts.
Leaked emails from an egg industry trade group revealed a plan to pay popular food bloggers to publish pro-egg content.77 Why? The egg industry is threatened by vegan egg replacement companies. So the egg industry trade group does what it can to preempt the rise of vegan alternatives.
Is it that far-fetched to think the meat, dairy, and egg industries are paying some of them to make anti-soy videos and articles? Soy is one of the main ingredients in vegan meat replacements. That makes it a direct threat to the meat industry. Would it be surprising to find out that fitness bloggers are converting their hundreds of thousands of followers into a small payday by making anti-soy content? Think about how many young men are influenced by fitness bloggers. Of course, some fitness bloggers could also genuinely believe anti-soy stuff, just like whacky aunts.
We only know about the egg industry’s efforts because someone leaked internal industry emails. So, if you’re a fitness blogger who posts anti-soy content in exchange for money from the meat, dairy, or egg industry, please admit it! I promise to link to your tell-all article.
I could go on with this topic, but I need to stop this post somewhere. Again, none of this is medical advice. This is the result of countless hours of reading about manboobs and soy. I’m not sure I’m proud of it, but it needed to be done.
My last piece of parting wisdom: you should really try this bbq tofu recipe.
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.
- Phthalate Study 2
- Environmental Health 2012
- Environmental Health 2012
- EHormone 1
- International Journal of Cancer 2
- Medical Hypotheses
- Human Reproduction
- Fertility and Sterility
- None of this content is medical advice.