- Is soya milk safe for men?
- Why are people concerned about men drinking soya milk?
- What we know about soya products
- What does the research say?
- So what’s the verdict on soya milk?
- What benefits does fermented soya have?
- Soya for BPH/Enlarged Prostate
- The truth about what soya does to men’s bodies
- Why Soy Is Controversial
- What We Know Today
- The Best (and Worst) Types of Soy to Eat
- 1. Soy milk is one of the most nutritious alt-milks
- 2. Soy milk likely will not mess with your hormones
- 3. Not all soy milks have GMOs
- 4. Soy milk can be super processed, so shop smart
Is soya milk safe for men?
Why are people concerned about men drinking soya milk?
Soya milk is a tasty and easily available alternative to dairy products, so it’s popular among people on a dairy-free diet. However, soya contains chemicals called soya isoflavones which are a source of phytoestrogens, and these have oestrogenic effects on the body – which is why we include soya isoflavones in our Menopause Support tablets.
For men, this has become a big concern, with some claiming that the phytoestrogens found in soya isoflavones can have feminising effects on men, such as breast enlargement and emotional changes, as well as cause problems such as erectile dysfunction, low sperm function and reduced libido.
On the flip-side, many people on dairy-free and vegan diets thrive on soya milk and other soya products with no adverse effects. Karris McCulloch at TheVeganKind claims ‘Soya yoghurts, soya milk, tofu and meat replacements are all consumed by our family regularly and we have absolutely no concerns whatsoever of the safety of soya consumption for either men or women. It’s becoming more and more widely accepted that the ill effects of soya on men are factually incorrect.’
So what truth is there in these concerns, and is it safe for men to drink soya milk or eat soya-based products?
What we know about soya products
It’s true that soya contains phytoestrogens which act like oestrogen in the body. However, their oestrogenic effect is very weak – between 50 and 20,000 times weaker than natural oestrogen! This can actually be really useful for women during the menopause, as phytoestrogen supplements like our own Menopause Support can gently support oestrogen levels. But don’t worry, you won’t find as many phytoestrogens in soya foods as you would in a supplement.
We know that soya products are widely consumed in Eastern countries, and the populations in these countries tend to be generally healthier with less hormone-related problems – women are less prone to PMS and tend to have an easier menopause, whilst men are less prone to problems like BPH, or enlarged prostate. However, it is important to remember that soya is not the only thing that makes Eastern diets so healthy – they are generally much lower in refined carbohydrates, richer in fresh vegetables and high in fish too.
It’s also important to consider what type of soya products these cultures traditionally consume. Fermented soya, such as miso and tempeh are most widely consumed, while soya milk is fairly uncommon. Fermenting soya increases its nutritional value so it’s likely that many of the health benefits associated with soya products in the East are actually in reference to fermented soya.
We know that soya milk also contains antinutrients, which can hinder the absorption of minerals such as magnesium and calcium. The fermentation process helps to reduce these antinutrients too.
Tempeh is a fermented form of soya.
What does the research say?
The good news is that research seems to suggest that soya has no adverse effects on men in terms of hormone disruption, sexual health or feminisation.
Two 2010 reports analysed a number of studies to assess the extent to which soya and soya isoflavones have an effect on male hormones and related conditions.
One of these concluded that there were ‘no significant effects of soya protein or isoflavone intake’ on male sex hormone levels.
Another report found that soya did not affect oestrogen or testosterone levels in men, did not affect sperm counts and did not increase the risk of erectile dysfunction.
The reports noted that while some adverse effects have been seen in animal studies, these animals process and react differently to soya than humans, and the same effects have not been found in similar studies on humans.
However, these reports don’t make a distinction between the different types of soy, with both including a range of studies which used different types of soya, from soya isoflavone supplements, to soya foods, to isolated soya proteins. We know that different types of soya have different levels of phytoestrogens, which skews these results slightly.
So what’s the verdict on soya milk?
Considering that the oestrogenic effect of soya isoflavones is anywhere from 50 to 20,000 times weaker than natural oestrogen, you’d have to drink an awful lot of soya milk to begin seeing hormonal effects. Plus, dairy milk contains lots of hormones and growth factors too so soya milk is still a better alternative.
However, just as we recommend reducing (or avoiding altogether) your intake of dairy, we’d also recommend limiting your intake of soya milk. Some soya milk in your morning cereal or in your tea/coffee is fine, but we wouldn’t recommend drinking pints of it throughout the day.
This is partly because soya milk tends to be highly processed in the UK and can often contain additional salt, sugar, preservatives and other nasty chemicals. It is also often made from non-organic or even GM soybeans. As we mentioned earlier, soya milk is an unfermented form of soya so it can also contain high levels of antinutrients.
However, we would recommend consuming more fermented soya products as these have lots of great health benefits! The fermentation process increases nutritional value and also reduces the levels of anti-nutrients to create a much healthier end product. Tempeh, natto and miso make great additions to a healthy diet.
What benefits does fermented soya have?
Soya is rich in nutrients such as protein, vitamins, minerals and fibre, and is a much healthier alternative to meat and dairy.
Fermented soya is also a natural probiotic, as the fermentation process encourages the growth of healthy bacteria. When ingested, these healthy bacteria can promote better digestion, which can have knock-on effects on the immune system, energy levels and overall nutrition.
Soya is also thought to be good for a healthy heart, since it contains omegas and can help to reduce cholesterol.
Soya for BPH/Enlarged Prostate
If you have BPH (an enlarged prostate) or are looking to promote a healthier prostate to prevent conditions like BPH from developing, then soya is something you should definitely think about eating more of. Soya is rich in plant compounds known as phytosterols which have been shown to reduce the risk of prostate enlargement.
The highest rates of prostate disease are observed in Western countries such as the United States, whereas the lowest rates are seen in Asian countries such as Singapore. While this could be down to factors such as genetics, one likely explanation is diet, and we know that Asian diets tend to be full of soya-based products.
Replacing some of your meat and dairy intake with soya-based products such as tofu, miso, tempeh and soya milk can also reduce the risk of BPH, since eating red meat daily has been revealed to increase the risk of BPH by 38%. Dairy is also a known inflammatory which can aggravate conditions like BPH and prostatitis.
For more diet tips, read our article on eating for a healthy prostate.
The truth about what soya does to men’s bodies
While some dietitians and scientists laud the humble soya bean for its vegan-friendly, fat-free, protein-rich composition, others argue that it inhibits male reproductive hormones.
So, what’s the deal? Is the Asian cuisine staple the nutritious plant-based product that so many hail it to be? Or is it really as bad for men as they say?
When it comes to men and soya, the majority of the alleged issues are surrounding sexual function and sex hormones.
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For example, research has linked regular consumption of soya in men to lower concentrations of sperm.
One study carried out by the Harvard School of Public Health in 2008 found that this was true for men who ate an average of half a serving of soya foods a day, with the effect being particularly prevalent in participants who were overweight and obese.
Meanwhile, another study from 2011 examined the effects of soya on one 19-year-old man who consumed large quantities of soya as part of a vegan diet. After careful analysis, his soya consumption was linked to erectile dysfunction and hyposexuality. His testosterone levels also dropped drastically.
However, as leading Harley Street nutritionist Rhiannon Lambert points it, it’s important to note that this research was conducted with just one participant who was also a type one diabetic and therefore there may have been additional factors that impacted the result.
“We cannot possibly apply the conclusion of one study based on one male to the larger population,” she told The Independent.
Similar conclusions were reached by another study conducted on male rats who were exposed to high doses of isoflavones in the womb, a compound which is rich in soya beans and soya products, and subsequently experienced a stunt in sexual organ development. Another study from 2000 had similar results.
However, it goes without saying that rats and humans are somewhat different in terms of almost everything and therefore Lambert argues that these studies may not be entirely reliable either.
One common misconception surrounding soya is that it causes hormonal imbalances, explains dietician Nichola Ludlam-Raine, depriving men of testosterone and promoting the production of oestrogen.
Ludlam-Raine argues that these myths typically derive from studies conducted on animals who have been given extremely high doses of soya, far more than the average human would ever consume.
“Animals metabolise soya very differently to humans and so the two cannot be compared,” she told The Independent.
However, when it comes to looking at research touting the benefits of soya, it’s worth noting that these are often conducted by companies and individuals whose best interest is to promote the health benefits of soya and therefore they may not be entirely unbiased datasets.
For example, one 2010 cross-reference study claimed that soya foods “do not have feminising effects on men” as some speculate.
However, this research was led by Dr Mark Messina, executive director of the Soy Nutrition Institute and the author of a book entitled The Simple Soybean and Your Health.
Messina also co-authored a study that same year which concluded that neither soya protein nor isoflavones had any effect on male reproductive hormones.
Despite the conflicting research, both Lambert and Ludlam-Raine advocate soya consumption as part of a healthy diet, particularly for those following a plant-based plan.
Regular and moderate consumption of soya products could also reduce cholesterol levels as proven in many studies, explained a spokesperson for the British Dietetic Association.
“Soya drink as a milk alternative is undoubtedly the best dairy-free option if you are vegan, as it has much higher protein levels than alternatives like nut or rice drinks marketed as ‘milk’ alternatives,” they told The Independent.
“Soya beans can also provide a contribution to your fibre intake.”
“Soya is a complete source of protein which makes it ideal is men following a vegetarian or vegan diet,” Ludlam-Raine added.
“Eating soya also has a positive impact on blood cholesterol levels which helps to reduce the risk of heart disease.”
However, scepticism surrounding the benefits to cardiovascular health remain rife, with the Food and Drug Administration pledging to revoke health claims surrounding soya as recently as October 2017 due to a paucity in scientific evidence proving the independent benefits.
With the overwhelming amount of disparaging information, it seems that soya consumption might best be left to personal preference, with Lambert explaining that one to two portions of soya a day is harmless to the average person, be they male, female or otherwise.
James Price’s breasts had been painful and swollen. It looked as if gum balls were implanted underneath each nipple. The slightest touch triggered throbs.
For Price, a retired U.S. Army intelligence officer who once flew attack helicopters in Vietnam, these changes were more than just physically uncomfortable.
“Men aren’t supposed to have breasts,” he says today in a quiet Texas drawl. “It was like my body was feminizing.”
A lean and wiry man, the breast development stood in stark contrast to the rest of his body. But it was not Price’s only symptom.
His beard growth had slowed, he’d lost hair from his arms, chest, and legs, and he’d stopped waking up with morning erections.
“My sexual desire disappeared,” he says. “My penis—I won’t say it atrophied, but it was so flaccid that it looked very small in comparison with the way it used to be. Even my emotions changed.”
Related: The Men’s Health Guide To Erectile Dysfunction: Everything You Need to Know to Keep Your Penis Healthy For Life
The first three doctors Price consulted diagnosed him with gynecomastia, or the abnormal enlargement of the mammary glands in men.
Tests further revealed that estrogen levels in his bloodstream were eight times higher than the normal limits for men, higher even than the levels typically seen in healthy women. Price’s estrogen was so high, in fact, that the doctors were at a loss to explain it. One physician became so frustrated he eventually accused Price of secretly taking estrogen.
“He thought I was a mental case,” says Price, still angry as he recalls the experience.
Dispirited and in pain, he decided to try one more doctor, this time a fellow military man.
He made an appointment with Lieutenant Colonel Jack E. Lewi, M.D., chief of endocrinology at the San Antonio Military Medical Center. During that first meeting, neither doctor nor patient had any inkling of just how long and complex this medical mystery would prove to be.
Dr. Lewi initially checked for “usual suspect” lifestyle factors known to trigger gynecomastia, from alcoholism to certain herbal ingredients, like tea-tree oils and lavender. With those ruled out, Dr. Lewi was left with a more dreaded suspect: an estrogen-secreting tumor.
Over the next few months, Dr. Lewi ran multiple tests, checking Price for cancer of the testicles, adrenal glands, chest, and lungs.
The good news: When the final test came back negative, Price was in the clear on all fronts. The not-so-good news: Dr. Lewi still had no clue what was causing his patient’s hormones to go haywire. But he was determined not to be the fourth doctor to leave James Price in limbo.
In the classes that Dr. Lewi teaches to medical students and residents, he has long offered this advice: If you’re not finding the right answers, you’re not asking the right questions.
Though he’d asked Price about his lifestyle and habits innumerable times, he decided to go back once again, and this time to make his questions as specific as possible.
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“I said, ‘Let’s go over your diet, meal by meal, and you tell me every single thing you eat and drink.’ He said, ‘Sure, Dr. Lewi. I get up and usually have some cereal.’ I said, ‘Do you put anything on it?’ He said ‘Soy milk.’”
Price explained that he’d developed lactose intolerance in recent years and had switched to soy milk exclusively. It had, in fact, become one of his favorite drinks, a great thirst quencher in the Texas heat.
Dr. Lewi suddenly felt his excitement building. He asked Price how much soy milk, on average, he drank each day.
“He told me, ‘Probably about 3 quarts,’” recalls Dr. Lewi about the moment that changed everything.
Over the past decade, soy foods and good health have become inextricably linked in the national consciousness.
According to annual U.S. consumer attitude surveys by the United Soybean Board, 85 percent of those polled in 2008 rated soy products as “healthy,” a significant increase from the 59 percent who in 1997 thought this was the case. Many men, to be sure, are hard pressed to explain why soy is supposed to be so healthy, but they take it on faith that they should embrace the bean.
“It’s something you need to train yourself to like, you know, for the health benefits,” my friend Larry, a distance runner, opined recently.
“Tofu’s the modern equivalent of cod liver oil,” added another buddy, Bill. Three times a week, his wife stir-fries tofu with chard. “It’s this gunk she calls superfood. I call it soylent green.”
He pauses a beat before adding, “I guess I’m grateful she gets me to eat it.”
Related: The Best Sources Of Protein For Men
Long the foundation of a vegetarian diet, tofu provides protein with little of the saturated fat and none of the moral indigestion that comes with meat.
Moreover, in the past decade, research has emerged suggesting that scarfing down soy may also play an active role in extending our lives. In 1999, soy protein earned a highly coveted FDA-allowed health claim: Diets that include 25 grams—about a pound of tofu—a day may reduce the risk of heart disease.
Related: 30 Easy Ways to Save Your Heart
Add to this the number of studies showing that soy protein might also help protect against prostate cancer, and suddenly the stuff starts looking like powerful medicine for men.
Of course, most medicines have side effects.
And when you consume soy protein, you’re actually courting the Mr. Hyde side of two natural drugs: genistein and daidzein. Both act so similarly to estrogen that they’re known as phytoestrogens (plant-produced estrogens).
Soybeans couldn’t care less about human sex characteristics—genistein and daidzein may have evolved to act as chemical defenses against fungi and grazing animals. (They aren’t very effective deterrents, apparently, since soy meal is widely used to feed livestock.)
But when humans consume these compounds in high enough quantities, they may experience gender-bending nightmares like James Price’s.
Related: How to Banish Your Man Boobs
What’s more, studies of these phytoestrogens in leading peer-reviewed medical journals suggest that even lower doses—such as the amount in the 25-gram soy protein target cited by the FDA—have the potential to wreak hormonal havoc.
Here are a few of the recent findings across the life stages of men.
Babies: Weaned On the Bean
A whopping 35 percent of bottle-fed babies in the United States receive at least some of their protein from soy.
The American Academy of Pediatrics (AAP) is taking steps to change this: It recommends that all infants who cannot be breastfed be given cow’s-milk formulas as the first preferred alternative. Healthy full-term infants should be given soy formula only when medically necessary, the AAP’s 2008 report states.
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Babies with an extreme form of lactose intolerance fall into this category, but many others who suffer from colic and excessive crying are switched to soy formula despite a lack of proven benefits.
Paul Cooke, Ph.D., a reproductive biologist at the University of Illinois, has studied mice raised on enough genistein to make their blood levels comparable to those of human infants fed soy formula.
Among other worrisome findings, he discovered significant shrinkage of the thymus gland, a key part of the immune system. “The thymus,” says Cooke, “is like a finishing school for white blood cells—it’s where they go to mature.”
Whether the same effect occurs in human infants is difficult to say, but a 2001 study in the Journal of the American Medical Association surveyed over 800 adults, ages 20 to 34, who were fed either soy-based or cow’s-milk formulas during their infancy.
One of the few differences to emerge was that the group raised on soy formula regularly used more asthma and allergy medications in adulthood. Was this just a quirk of the sampling—or could it represent a subtle impairment of immune function?
“I don’t know the answer,” says Cooke. “But the point is I don’t think anyone knows. There are 20 million people in the United States alone who have consumed soy formula as infants. When people ask me about doing experiments, I tell them we already are—with a large chunk of the country’s population.”
For now, at least, the United States is gambling that widespread use of soy formula won’t lead to long-term consequences.
In 2005, Israel’s health ministry recommended that soy products be limited in young children and, if possible, avoided altogether in infants. In issuing such a caution, Israel joined France, New Zealand, and Australia in officially embracing a better-safe-than-sorry approach for the next generation.
Teens to 20s: Faux Muscle Fuel
Most weightlifters, whether they’re dedicated competitors or occasional gym rats, understand the importance of protein in muscle building and repair. And research has shown that the timing of when you swallow that protein is just as critical—a fact that’s created a market for easy-to-consume protein supplements.
Related: Workout Nutrition: What and When to Eat to Build Muscle
“It’s kind of hard to throw a steak down right before or after a strength workout,” says William Kraemer, Ph.D., a professor of kinesiology and a preeminent researcher of strength training and human performance at the University of Connecticut.
Protein supplements allow an athlete to dump a scoop of powder in with some juice and chug what he needs, when he needs it.
Giant canisters of the stuff line the shelves at GNC and similar health-food stores nationwide, each brand touting its unique muscle-building properties. The most common sources of protein used in them are soy, whey, and casein.
But the latter two, which come from animal sources, are more expensive to produce than soy. The question currently being debated by strength trainers and researchers is this: Does soy’s relative affordability come at a cost to muscle gains?
Related: The Best Protein Powder For Men
In a 2005 study in the Journal of Nutrition, researchers comparing soy to casein concluded that “the biological value of soy protein must be considered inferior to that of casein protein in humans.”
Among other disadvantages, the researchers found, a significantly larger portion of soy is degraded to the waste product urea. Moreover, it contributes to less protein synthesis in the body.
“A protein like whey has much more robust biological effects than soy,” acknowledges Kraemer.
In terms of strength gains, however, he says more research is needed before he can provide definitive guidelines.
“But my personal opinion is that soy protein is cheaper and whey protein is higher quality,” he says. “There are also concerns that soy might decrease a man’s testosterone production and increase his estradiol production, which we tend to associate with female hormone production.”
Related: Is Testosterone Therapy Safe?
After retiring from military service, James Price and his wife, Donna, moved to a small farm in Texas.
He had a commercial pilot’s license and split his time between flying and working the land. His passion was raising and training quarter horses that he broke himself. Price lived the kind of cowboy lifestyle that few of his friends, even those decades younger, had the stamina to sustain.
Donna cooked well-balanced meals, nothing fancy, just standard American fare. It was a good life.
Then Donna developed glioblastoma multi-forme, a lethal type of brain cancer. When she died, Price, then 55, was left to cope not only with his grief but a radical change in his daily routine. Not surprisingly, the diet of the new widower took a hit.
“All of a sudden,” he says, “I was living on not-so-healthy meals I’d make for myself.”
Related: 5 Healthy Eating Hacks For Guys Who Hate to Cook
He saw a product advertised on TV called Ensure; it was supposed to provide adults all the vitamins and minerals and other vital nutrients necessary for health. He also started drinking milk, a favorite from his childhood that he figured would supply protein and other nutrients.
Unfortunately, Price soon discovered he was lactose intolerant.
“I switched to soy milk because it’s lactose-free,” he says, “and I had heard that soy milk is supposed to be good for you.”
He tried it and liked it. Soon soy milk became a regular item on his shopping list, something he bought on autopilot.
In the wake of Donna’s death, Price’s body as well as his emotions began to change, often in ways that were hard to separate from normal grief.
Mood swings and a decrease in libido are not unusual companions to bereavement. But Price had a nagging sense that something was off.
“I was becoming much more sentimental,” he recalls, describing his emotions as almost feminine. “I’d break out and cry at a sad movie, that kind of thing. It just wasn’t like me.”
When Price began dating again, it was as if the sexual aspect had evaporated. “I enjoyed the company of women,” he says, “but it was just like they were my friends. Even if I had wanted to do anything physical, I couldn’t have.”
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The gynecomastia that eventually developed became deeply humiliating for Price. He stopped wearing T-shirts even on the hottest days, fearing his friends and neighbors might see the telltale bumps beneath the fabric. His breasts by this point resembled the buds of a pubescent girl.
Never once in the subsequent yearlong ordeal of medical testing did it cross his mind that soy milk might be the cause.
“I had no idea,” he says. “I never gave it a second thought.”
The day Dr. Lewi asked him to stop drinking the stuff, he immediately complied. He also began checking the ingredient labels on all other items he regularly consumed. If Dr. Lewi was right, going cold turkey on soy just might begin to reverse the symptoms.
Over the next several months, blood tests revealed Price’s estrogen levels were, indeed, dropping steadily back toward normal.
Even better, the extreme nipple tenderness began abating. Eventually, his breasts stopped hurting completely and he gradually began feeling a little more like his old self.
Dr. Lewi, who had searched the medical literature extensively when trying to solve Price’s case, had come across no papers linking soy to gynecomastia.
Realizing his obligation to warn other doctors about the possibility, he told Price he wanted to follow him for several more months and eventually write up his case for a medical journal.
Price readily agreed, grateful for the chance to spare others from his ordeal.
20s to 40s: Privates in Peril
In a Harvard study published last year in the journal Human Reproduction, Jorge E. Chavarro, M.D., Sc.D., and his colleagues found a strong association between men’s consumption of soy foods and decreased sperm counts.
Related: 4 Ways to Boost Your Fertility
Ninety-nine men reported their intake of 15 different soy-based foods, then underwent semen analysis. Those in the highest category of daily soy intake averaged 32 percent fewer sperm per milliliter of ejaculate than those who went sans soy.
Dr. Chavarro cautions that this doesn’t prove cause and effect, and that it’s too early to counsel men to avoid soy foods in the hope of boosting fertility.
“But clearly, this story is just starting,” he says. “More studies need to be conducted.”
If shooting blanks is worrisome, how about being unable to shoot at all? Two other recently published papers reveal that at least one soy component clearly impairs erectile function in animals—and may do so in men as well.
The studies, published in the Journal of Andrology and Urology respectively, looked at the effect of daidzein on the sexual function of male rats.
Moderate doses of the phyto-estrogen administered either in youth or adulthood significantly affected the quality of their erections. Among other changes, the daidzein-exposed males produced less testosterone, had softer erections, and experienced biochemical changes to their penile tissues that left these tissues less elastic and less capable of complete blood engorgement.
Related: 10 Myths About Erectile Dysfunction
While acknowledging that rat results do not always directly translate to humans, the authors of the first study suggest that this time there’s reason to believe they will.
They cite, among other things, a 10 percent higher incidence of erectile dysfunction in Chinese men known to consume high amounts of soy compared with Americans who avoid it.
The authors of the Urology study sound a similar warning. They argue that it’s reasonable to believe that men who consume lots of daidzein could experience tissue changes similar to those seen in another mammal.
Yufeng Huang, M.D., a coauthor on both papers, says that the “moderate” dose used in the animal studies leads to approximately the same blood level of daidzein in men who eat soy every day, a common practice in Asia. He believes soy represents a novel and previously overlooked risk factor for ED.
“We are now recommending that soy be avoided by patients with erectile dysfunction,” Dr. Huang says. And because erectile dysfunction increases with age, he also suggests that men ages 40 and above limit their soy intake.
Related: Do You Need Erectile Dysfunction Drugs?
50s and Beyond: Brain Drain
Last summer, Eef Hogervorst, Ph.D., of England’s Loughborough University, and other researchers published a study on soy products and dementia risk.
The researchers focused their attention on older Indonesians, members of a culture in which tofu has long been a dietary staple. Hogervorst says her team began the study confident of finding a benefit from tofu’s phytoestrogens.
“Almost everything we’d learned from animal and cell-culture work indicated that estrogenlike compounds protect the brain,” she says.
In older men and older women alike, however, they found exactly the opposite indication: Participants over age 68 who were regularly eating the most tofu had double the risk of dementia and memory impairment as those consuming a more moderate amount.
“We were very surprised by this at the time,” says Hogervorst, “but a new consensus is starting to form now. Hormones and hormonelike products are not very good for people over 65.”
Related: 8 Daily Habits That Will Keep Your Brain Young and Sharp
In terms of soy itself, Hogervorst suspects its reputation is changing.
“For a long time now,” she says, “people have been finding only good things about phytoestrogens. Gradually, as some contrasting information accumulates, the paradigm changes 180 degrees and you see people arguing that phytoestrogens are all bad. The truth probably lies somewhere in the middle.”
Dr. Lewi’s case report on James Price’s condition was published in the May/June 2008 edition of Endocrine Practice, a journal read by many of the nation’s in-the-trenches endocrinologists. Thanks to this, doctors now have a newly documented agent to consider when evaluating gynecomastia.
For his part, Dr. Lewi believes that soy products in moderation can still be a healthy part of a man’s diet.
“The problem,” he says, “is when a thing like soy is touted as this wonderful panacea for health, and people end up going overboard on it.”
A final twist in the Price case, however, shows how difficult it can be to avoid soy. During the follow-up blood testing Price agreed to undergo, his estrogen levels continued to drop, in a virtually linear fashion, back toward normal.
Then, several months later, and seemingly for no reason, the positive trend reversed. As soon as he saw that Price’s estrogen was once again climbing, Dr. Lewi called his patient.
Before Dr. Lewi could even announce the results, Price said, “I already know what you’re going to tell me, Dr. Lewi. You’re going to say my estrogen level is coming up.”
Dumbfounded, Dr. Lewi asked Price how he knew that without seeing the test results.
Price explained that after switching from soy milk to lactose-free milk, he was in the grocery store one day and bought some more Ensure. Though he’d followed Dr. Lewi’s advice and checked the labels on virtually every product he purchased, he’d neglected to check Ensure.
“It’s advertised as having vitamins and minerals and all the stuff you need to stay healthy,” he says.
Related: The Best Multivitamins For Men
Only after his breasts started hurting and growing again did it occur to Price that Ensure might also contain the last thing his body needed. He checked the label: Ensure contained soy protein. He told Dr. Lewi that he threw out the rest and was no longer drinking it.
Subsequent blood tests showed that this was enough to send Price’s estrogen back in the healthy direction.
Several months later, his estrogen levels—once higher than those of most women—were in the low-to-normal range for healthy men. They’ve remained in that range ever since, but the physical changes to his penis, his loss of sexual desire, and his heightened emotions have persisted.
Related: The Male Libido Crisis
And while all pain associated with his breasts has disappeared, the tissue unfortunately remains swollen, a consequence of fibrotic tissue changes that take place with long-term gynecomastia.
Although Price remains self-conscious about it, he’s reluctant to try the only cure—cosmetic surgical reduction. There are too many risks, he says—bleeding, infection, problems with anesthesia—to justify going under the knife at this point in his life.
As for other men who might one day develop a similar problem, Price’s advice is unequivocal: Go to your doctor at the first sign of pain or swelling. Symptoms caught and treated early are often reversible.
Price also acknowledges that his body may have an above-average sensitivity to soy’s phytoestrogens.
Still, his experiences have taught him that the foods we eat are not always what we think they are. Soy protein today is an ubiquitous, profitable, and often buried ingredient in a bewildering number of packaged foods. More than most people, Price was doing his best to avoid it. But he was still tripped up.
“In today’s supermarkets,” he says, his voice weary, “you can’t hardly get anything without at least some soy in it.”
Jim Thornton Jim Thornton is a National Magazine Award–winning health writer and champion masters swimmer.
Depending on what you eat everyday, soy-based foods like tofu, soy milk, miso, tempeh, and edamame may sound like classic “health” foods. But for vegetarians, vegans, and other dieters who have come to rely on this common meat alternative in their diets, grocery store items rich in soy have developed scary reputations for a purported “disease risk.” Some previously published research can be downright scary, with claims that increased soy can mess with your hormones, the thyroid, and possibly cause cancer.
So which side of this debate is actually right — does soy deserve that health halo, or should you swear the stuff off of your shopping list for good?
As is often the case when it comes to nutrition, the answers aren’t black and white. But for the most part, “Soy-based foods are some of the best foods you can eat on the planet,” says Jaclyn London, MS, RD, CDN. “Soybeans provide a plant-based protein source; a slew of vitamins and minerals crucial for reducing risk of chronic disease; and fiber that helps you fill up and feel satisfied.”
While some small, poorly designed studies have led to inflammatory headlines over the years, it’s important to think about all foods in context. Eating plant-based foods in their closest-to-nature (a.k.a. least processed) form? Super nutritious. But taking supplements made with the compounds in soybean? Not so much.
“That’s where we’ve seen health risks,” London explains. “In fact, it’s not uncommon to see research reflecting consuming compounds in supplement form rather than eating the foods themselves.” Those supplements are linked to increased disease risk, while real, whole foods are linked to decreased disease risk.
Why Soy Is Controversial
Let’s take a trip back to the 1990s, when soy foods first started really hitting it big. At the time, many experts believed that soy had the power to fight problems like obesity, heart disease, and even cancer. After all, people in Asia eat a ton of soy. And studies showed that these populations had significantly lower rates of obesity, heart disease, and breast cancer compared to people in the U.S. Clearly, soy was the miracle food, right?
Not necessarily. Those studies only looked at associations, not causation. Just because people who consume a lot of soy also happen to be healthier than people who don’t eat soy doesn’t automatically mean that soy is the key to their superior state. Countless other factors — from genetics, to lifestyle, to the rest of their diet — could also play a role.
When researchers began taking a closer look to find out what made soy so healthy, they ran into some surprises. Soy, it turned out, contains estrogen-like compounds called isoflavones. And some findings suggested that these compounds could promote the growth of some cancer cells, impair female fertility, and mess with thyroid function. Some health experts also trash-talk soy because of its potential to be an endocrine disrupter — meaning it can mimic estrogen in the body, which may lead to a hormone overload.
At the same time, other studies were still showing that soy consumption could cure high cholesterol and help women cope with the symptoms of menopause. And Dawn Jackson Blatner, RDN, a Chicago-based dietitian, says that while whole soy does contain natural plant estrogens, they’re much weaker than actual human hormones, and shouldn’t case you worry. Add it all up, and you can see how this little green bean became a source of mass dietary confusion.
What We Know Today
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As with all foods, experts still don’t know everything there is to know about soy. But research in recent years suggests that moderate consumption of minimally processed soy foods (more on what those are later) not only isn’t bad for you, it probably has some benefits. Here’s what we can say about soy today:
Soy may decrease your risk of certain cancers, among other chronic diseases.
How did soy even get linked to cancer risk in the first place? Stephanie Clarke, RDN, a dietitian based in Washington, D.C., says it has to do with processed grocery products. Soy protein isolates, a highly processed form of soy used in cereals, protein bars, and snacks (among other foods), may contain more soy isoflavones, which are organic compounds that can also be considered endocrine disruptors in high amounts. Elevated levels of this kind of soy may lead to unbalanced hormone levels, which can play a factor in cancer risk.
The majority of recent, high-quality studies, however, have found that unprocessed soy doesn’t increase breast cancer risk, and very high consumption could even offer some protection.
Eating soy could help protect against other types of cancer, too. Findings show that soy consumption may slightly lower the risk for gastrointestinal cancers and have a protective effect in prostate cancer survivors. Eating a high-fiber diet is also tied to lower colon cancer rates, and soy foods like edamame and tempeh both have plenty of roughage.
The only instance in which you may wish to limit soy consumption? If you’ve previously been diagnosed with estrogen receptor-positive breast cancer, Clarke says. Your doctor may advise that it’s best to skip soy altogether if estrogen is at play in this case.
Soy might improve fertility and help with hot flashes.
Soy appears to be beneficial for fertility, as long as you don’t eat too much. Women undergoing in vitro fertilization who have environmental exposure to BPA are more likely to get pregnant if they also ate soy. That’s likely because soy’s isoflavones help neutralize the BPA’s endocrine-disrupting effects, researchers say.
Just don’t go overboard. Consuming over 100mg of soy isoflavones (the equivalent of 6-ounces uncooked tempeh or 16 cups soy milk) daily was linked to reduced ovarian function, found a Journal of Nutrition review. But moderate soy consumption didn’t pose a problem.
As for soy solving hot flash problems? It might help, but not for everyone. Among women whose bodies produce the soy metabolite equol, those who ate the most soy experienced significantly fewer hot flashes and night sweats compared to those who ate the least, found one Menopause study. (Between 20% and 50% of North American and European women produce equol. Some research centers can test for it in a urine sample, but there’s an easier option: Try adding soy to your diet for four to six weeks and see what happens. If it helps, you produce equol. If it doesn’t, you probably don’t, the study authors say.)
Eating soy in place of meat will probably protect your heart.
Early research suggested that soy could help lower levels of bad cholesterol. But more recent findings have shown that might not be the case, and in 2008, the American Heart Association said that there wasn’t enough evidence to say for sure that soy lowered the risk of heart disease.
Still, it’s safe to assume that soy has some benefits going for it. In general, replacing animal foods with plant foods like soy lowers saturated fat intake and ups fiber intake, both of which are help your heart. In other words, swapping that steak out for tofu or tempeh is a heart-smart move. But having steak followed by a bowl of soy ice cream for dessert probably won’t be as helpful.
You should pay more attention to your soy intake if you have thyroid issues.
Soy foods don’t affect thyroid function in people with healthy thyroids, found a Loma Linda University review of 14 studies. But if you have an underactive thyroid, you might want to watch how much soy you eat. Soy foods have been shown to interfere with the body’s absorption of thyroid medication — but only if you overdo it, suggests a 2016 Nutrients review. The evidence is still far from conclusive, but experts still advise to wait at least four hours after consuming soy to take your thyroid medicine.
The Best (and Worst) Types of Soy to Eat
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All of soy’s potential benefits come with an important caveat: To reap them, you need to pick minimally processed forms of soy — think tempeh, tofu, miso, and edamame, all three experts say.
These foods serve up soy’s entire nutritional package without added sugar, unhealthy fats, sodium, or preservatives that you usually find in highly processed foods.
Soy frankenfoods like meat analogs, soy bars, soy yogurts, or protein powders usually only contain soy protein isolates, rather than nutrition from the whole soybean. “Just as other processed foods are lower in nutrient density, removing the protein from the other enzymes and bacteria needed for digestion affects the nutritional quality,” says Dr. Taz Bhatia, MD, integrative health expert and author of What Doctors Eat.
As for how often you should eat soy? As with all foods, moderation is the way to go. Generally, three to five servings of minimally processed soy foods per week are perfectly fine, Bhatia says. If you’re unsure, or you have an underlying health condition (like hypothyroidism), bring it up with your doctor the next time you discuss your diet.
Safe Ways to Enjoy More Soy Marygrace Taylor Marygrace Taylor is a health and wellness writer for Prevention, Parade, Women’s Health, Redbook, and others.
In 2019, drinking soy milk is about as cool as Cady Heron at the beginning of Mean Girls. (Translation: Not very.) Newcomers oat milk, almond milk, and even sesame milk have taken precedence on store shelves and in alt-milk drinkers’ hearts.
So why has the OG dairy-free milk missed out on the glory of the current alt-milk revolution? “I think the main reason soy milk isn’t as trendy as some of the other options out there is because it’s been around for decades and people always want the latest and greatest thing,” says Mark Messina, PhD, MS, the executive director of the Soy Nutrition Institute, a research organization created by the US Soybean Association and industry executives.
But there are other elements beyond the “cool factor” at play too, he says. Dr. Messina, who has studied soy’s health effects since the 1990s, says that there have been a lot of misconceptions about the plant (and its associated products like soy milk) over the years. But some of those concerns…well, they aren’t totally justified. Here’s the low down on what you should actually believe about soy milk.
1. Soy milk is one of the most nutritious alt-milks
A 2018 study found soy milk to be the most nutrient-dense plant milk compared to rice, almond, and coconut milks. Soy is actually the plant-based option that mostly closely resembles dairy milk in terms of its nutrient profile. “It can be a source of protein and calcium, especially for people that are dairy-intolerant,” says Taz Bhatia, MD, a women’s hormonal health expert and board-certified integrative medicine physician. (Soy milk has seven grams of protein compared to milk’s eight grams per serving, and both have 300 milligrams of calcium.) It’s also rich in vitamins A, D, and K.
It is also a fairly sustainable choice for the planet. The BBC recently cited Oxford University research that found soy milk requires less water to make than dairy, almond, and oat milks, and production of it creates fewer emissions than rice and dairy milks (but more than oat or almond milk).
2. Soy milk likely will not mess with your hormones
One of people’s biggest hangups about soy milk (and soy in general) has been its association with hormones. “Soy contains isoflavones, which are a type of phytoestrogen,” Dr. Messina says. In soy beans, phytoestrogen acts as a defense system and helps cells communicate. But these plant compounds can act similarly to (or potentially interfere with) estrogen in the human body.
As people started to learn more about hormones, the idea of soy naturally having high amounts of these estrogen-mimicking compounds caused lots of concern. Integrative and functional doctor Frank Lipman, MD, has written in the past about his dislike of soy, saying it can disrupt thyroid and endocrine function, which can lead to fatigue, constipation, and affect menstruation and menopause. (Scientific studies generally dispute the belief that soy affects thyroid function in healthy adults; there is some evidence to suggest that consuming soy on the reg for a long period of time could affect the endocrine system.)
However, two of the experts we spoke to disagree with these concerns. “ have effects that are unrelated to estrogen and even their estrogen-like effects are different from the hormone estrogen,” Dr. Messina says. Translation: Just because phytoestrogens are similar to estrogens doesn’t mean they’re the same thing—nor will they necessarily have a negative impact on your body. Dr. Bhatia agrees. “Phytoestrogens are different from regular estrogens, and serve a different purpose,” she says.
She adds that research has shown soy (and its isoflavones) can actually be good for you. “Phytoestrogens can bind to estrogen receptors, so in this way they are actually protective against hormone-based cancers,” she says. She stresses that soy does not cause cancer or have to be avoided in people with hormone-based cancers—a sentiment echoed by the American Cancer Society.
However, Heather B. Patisaul, PhD, associate professor in the department of biological sciences at North Carolina State University and an expert on endocrine disruptors, says that there are some caveats to the overall safety of phytoestrogens (like what’s in soy.) “How phytoestrogens might impact health depends on a lot of factors including your age, sex, stage of development, and general level of health,” she says. While most people will not have any negative health effects from a moderate intake, Dr. Patisaul says that people who are pregnant, in treatment for hormone-related cancers, or taking thyroid medications might consider talking about their diet with their doctor to ensure that their soy consumption won’t interfere with their health.
3. Not all soy milks have GMOs
Another strike against soy: GMOs. Soy is one of the most common genetically-modified foods in the U.S., which many conscious consumers are avoiding. However, Dr. Messina says that the bulk of that GMO soy is going to animal feed and not into soy milk or other soy foods. To his point, many popular soy milk brands are non-GMO, including Silk and WestSoy. Look for brands with an organic or certified non-GMO label to be 100 percent in the clear.
4. Soy milk can be super processed, so shop smart
Soy milk can be part of a healthy diet, but Dr. Bhatia says it’s important to remember that not all sources of soy are nutritionally equivalent. “Fermented soy such as miso, tempeh, and natto help balance the gut,” she says. “But soy in highly processed foods lack the same nutritional value,” she says (which is generally true for any whole food versus its processed counterpart).
Examples of the most processed soy foods include soy burgers and bars. Dr. Bahtia says some soy milks can be highly processed too, which affects its nutrient density (meaning you won’t get as many protein, vitamins, or minerals per serving). Before buying, check that nutritional panel. If the amount of vitamins A, D, K, calcium, and protein are almost nil, that likely means there’s a lot of fillers in there—and not even really all that much soy. The ingredients list should be minimal, and check that the milk is coming from whole beans, not the more processed soy protein or soy protein isolate.
Of course, soy isn’t for everyone. “Some people are intolerant to soy, which can cause digestive issues,” Dr. Bhatia adds. Many people are also just straight-up allergic to soy, making eating any product with soy a complete non-starter.
But in general, Dr. Bhatia gives the green light for consuming soy milk regularly, up to three times a week. “Go for a good quality one and non-GMO if you can,” she says. Sometimes the oldies really are the goodies.
Now that you’ve been schooled on soy, get the low-down on if starchy foods like rice and potatoes are healthy.
The many forms of soy
Soy milk is a common way to consume soy, but soy by-products are also used in many everyday food items.
According to the World Wide Fund for Nature, soy oil – produced from crushing soybeans – is the second-most consumed oil in the world after palm oil. It’s used in foods like commercially baked goods, margarine, salad dressings and mayonnaise.
Soy meal, which is a by-product of making soy oil, is the most common protein feed in the world for chickens, pigs and dairy cattle. So, by consuming dairy, meat and eggs, we’re inadvertently eating soy as well.
Another commonly consumed soy product is soy protein isolate, which is a dry powder that has been ‘isolated’ from the rest of the soybean to retain the majority of the protein. With an average protein content of 90%, it’s mainly used in protein drinks, protein bars, baby formula and vegetarian meat alternatives, and is sometimes used to improve the texture of meat products.
Soy and estrogen
The main controversy with soy stems from its naturally occurring isoflavones, a class of phytoestrogens found predominantly in legumes and beans. These plant-based estrogens are thought to mimic estrogen in our bodies. Soy isn’t the only food to contain isoflavones, but it has a very high concentration of them and is more widely consumed.
The first documented study of the impact of soy consumption was a 1946 study in The Australian Veterinary Journal, which documented fertility and breeding problems in sheep feeding on Western Australia’s isoflavone-rich clover.
Since then, hundreds of worldwide studies have looked into soy’s effects on the body, especially in relation to hormones and cancer.
While some studies have shown benefits in cancer prevention (namely breast, stomach, prostate and pancreatic cancers) others have refuted the claims, stating that consuming soy could actually increase the chances of cancer – especially in women who’ve already had breast cancer.
Further studies have shown both a connection and a lack of evidence for increased cardiovascular health, thyroid function and treatment of menopause.
This lack of conclusive research has contributed to the ongoing debate in both the public and medical arenas over soy’s validity as a health food.
Soy and genetic modification
It’s estimated that 90% of soybean production is genetically modified. Genetically modified foods are modified to be resistant to certain herbicides, meaning that each soy plant can be sprayed several times with herbicides that will kill the neighbouring plants and weeds. However, studies are inconclusive as to whether GMO foods have an effect on the health of humans.
Should we eat soy?
With little conclusive evidence either way, it can be challenging to understand the effects of regularly consuming soy. So, what does Australia’s leading cancer authority suggest?
Cancer Council admits the effects of phytoestrogens on the body, especially from soy, are not “fully understood”. It does, however, recommend that a moderate consumption of soy foods (1-2 serves a day), along with an overall healthy eating plan, is “unlikely to have adverse effects”. A serve is 1 cup of soy milk, ½ cup of tofu or roughly 8-10 grams of soy protein.
Cancer Council also states that soy or isoflavone supplements shouldn’t be used in the belief that they’ll prevent cancer, as there is “no evidence” to this effect.
Reid agrees and adds that “consuming soy in its traditional, unmodified sense and unprocessed varieties can be a great addition to the diet, particularly when it replaces animal products that are higher in saturated fat and cholesterol.”
Unmodified soy foods include whole soybeans, tofu, tempeh and soy beverages made from whole soybeans. Highly processed soy products that Reid recommends avoiding include soy pills and powders.
“Check the label and look for ‘soy protein isolate’,” she says. “This is an extracted, refined protein from the soybean – in other words, it’s not a whole food.”
For alternative non-animal protein sources, Reid advises eating a variety of plant proteins such as lentils, other legumes like chickpeas, kidney beans, broad beans, nuts and seeds, and nut butters. As these foods don’t contain all the essential amino acids, she believes that eating a combination of them is the best approach.