You probably know by now that soy protein is pretty awful stuff for athletic populations. Here’s the article that first exposed the dirty truth.
In 1949, the US government released clouds of bacteria over San Francisco to literally see what would happen. No one, other than the government, knew about it. Luckily, only one person died, but 11 others were admitted to hospitals.
In 1952, the government released clouds of zinc cadmium sulfide into an elementary school population to see what would happen. No one died, at least until years later, when these same children, then adults, succumbed to “higher than would be expected” rates of cancer.
These same types of bacterial/chemical experiments continued until 1969.
Of course, most of us would probably categorize all of those events as ancient history and reason that now that it’s the year 2000, such things could never happen again. Well, in my mind, something akin to those barbaric experiments is taking shape right now, although, at least on the surface, it seems a whole lot more innocuous than exposing a population to a cloud of pathogens.
The following blurbs from a big-city newspaper (San Diego Union, December 8, 1999) raised my hackles:
Certain soy products can now sport a heart-healthy label from the US Food and Drug Administration. The new claim will say “25 grams of soy protein a day, as part of a diet low in saturated fat and cholesterol, may reduce the risk of heart disease.”
Further down in the same article came this ominous note:
In a study by Roper Starch Worldwide, 50% of adults say the new claim will lead them to eat more soy foods or to try them for the first time. The Roper poll found that consumers are most inclined to try soy burgers, soy flour, and soy protein bars.
Then, a couple of weeks later (San Diego Union, December 24, 1999), I read the following news items:
The US Department of Agriculture is proposing dropping its restrictions on how much soy can be used in meals. Under current rules, soy can only be a food additive and only in amounts less than 30%.
Other facts jumped out at me:
School officials are more likely to use it to increase the amount of soy that they blend into their standard fare, like burgers, tacos, etc.
Market research sponsored by the United Soybean Board indicated that 26 million children who participate in school lunch programs would accept soy products.
Nutritionists in the San Diego Unified School District, which serves meals to more than 100,000 children daily, already use soy to make hamburger patties, says Jane Boehrer, food services director.
In essence, soy is about to become very hot, so much so that you might have trouble avoiding it. Soy has also experienced a resurgence in the bodybuilding market. More and more products are touting soy’s benefits, which include a superior PDCAAS (protein digestibility corrected amino acid score), the above-mentioned beneficial effects on cholesterol, improved thyroid function, and enhanced immune function.
I won’t argue any of that. And, I’ll go as far as to say that supplementing your diet with soy is a good idea…if you’re either a female or a eunuch.
So do I really think that the government is conducting a mass experiment with the entire US population as its cadre of lab rats? And, more importantly, what did I mean by that last crack about females and eunuchs?
The answer to the first question is no in that I don’t think that they’re intentionally out to sabotage the endocrine status of males. I do, however, think that they’re either ignoring the underlying problems associated with soy in the assumption that improved cardiovascular profiles are more important than maintaining a healthy hormonal profile.
Let me explain.
As many of you know, soy contains “healthy” amounts of compounds known as phytoestrogens, which are simply plant chemicals that mimic the action of animal estrogen. (For the purposes of this article, the term “estrogen” is intended as a generic term for any substance that exerts biological effects characteristic of estrogenic hormones such as estradiol.)
Now, phytoestrogens can affect mammalian cells in two ways that I know of – they can either bind to high-affinity, highly specific receptors in the cell nucleus which, in turn, attach to DNA regions of genes that lead to protein transcription, in effect acting as a real estrogen, or they can simply bind to these receptor sites and sit there, preventing real estrogen from getting its parking space and initiating transcription.
The first possible effect is highly undesirable if you’re a male because estrogen, in addition to being the primary “female” hormone and responsible for a host of “feminizing” effects, also, in greatly simplified terms, makes it harder to put on muscle.
Now, it could be argued that yes, these phytoestrogens act as estrogen, but very weak estrogen. So if they prevent a “strong” estrogen from setting up shop on the receptor, you’re ahead of the game. That’s a good point, unless you have a low level of estrogen in the first place, which would mean that the weak activity of the weak estrogen itself can exceed whatever estrogen activity is being blocked, leading to a net increase.
The second possible effect can be a good one. If an inert substance, like a “friendly” phytochemical, prevents estrogen from binding to a receptor site and initiating protein transcription, you miss out on all of the negative effects of estrogen (possible increases in bodyfat, gynecomastia, and maybe even benign prostatic hypertrophy, or BPH).
Unfortunately, soy protein contains two rather significant “unfriendly” phytoestrogens, both of which appear to have estrogenic activity. They are called genistein and diadzein.
I maintain that male physique athletes – or, for that matter, virtually all males – should avoid taking in large amounts of soy protein on a regular basis. This holds true for school-age kids, too.
Obviously, the government has made it a lot more likely that the US population, including prepubescent and adolescent males, is going to be eating fairly significant amounts of soy protein. What will be the results of this “soy mania?”
I can’t be sure – any more than the Y2K experts were sure of what would happen on January 1 – but it could be increased feminization of our school-age children, increased feminization of our male adults and all the baggage that carries, and possibly even increased rates of infertility and an even more universal increase in BPH.
Am I a Chicken Little, or is there genuine cause for concern? The studies seem to back me up. Some point to the hint of estrogenic activity, while others point to more serious problems.
One in particular, using mice, found genistein (2.5 mg/kg of bodyweight for nine days) to result in reduced testicular and serum testosterone concentrations, in addition to a reduced amount of luteinizing hormone in the pituitary.(1) They concluded that genistein, when given to adult males, “induced typical estrogenic effects in doses comparable to those present in soy-based diets.”
Another found that a soy and alfalfa-free diet with a 0.1% concentration of genistein decreased the rate of bodyweight gain in Sprague-Dawley rats and a marginal decrease in prostate weight.(2) (Although avoiding prostate hypertrophy is a good thing in adults, a decrease in prostate weight is indicative of feminizing effects.) The scientists concluded that scientists who do endocrine toxicology studies should use phytoestrogen-free diets, lest the phytoestrogens interact with manmade chemicals and screw up the results.
Others found more serious problems. One cited “significant testicular cell death” when genistein was administered.(3) They noted that while sodium azide, a highly toxic chemical that’s a potent vasodilator, killed testicular cells by inducing necrotic death, genistein killed them by inducing apoptoic death (in essence, fragmentation of the cells) – a small distinction, in my book. This sperm death may be a result of their inability to repair themselves. (4)
Much of the research is geared toward reproductive disorders in wild animals, captive animals, and the animal known as man. One study suggests that developmental and reproductive disorders in wild animals have been associated with a high exposure to environmental chemicals that also have estrogenic activity.(5) He conducted experiments in which he exposed rat endometrial cells to various compounds, including genistein and diadzein, and found them to indeed affect a certain protein that affected fertility.
Although Hopert’s study pegged females, part of the reproductive problems might very well stem from the affects of phytoestrogens on the male, as the above studies suggest.
Similarly, a study of cheetahs in captive breeding programs, most of which ingest a commercial diet that includes hefty amounts of soy, suffered from infertility and a high incidence of liver disease. (6) The incidence of liver disease is, perhaps, the topic of another article.
There’s been documented decline in human male sperm count in the last 50 years, and various theories have been bandied about as to its cause. Many scientists believe that it coincides with an increase in exposure to estrogen-like compounds. Although soy hasn’t typically been a major component of diets in the western world, that may be about to change.
It’s true that the Japanese and Chinese have long ingested soy and soy products and, quite obviously, they don’t appear to suffer from infertility. Of course, they’re probably not exposed to the incredible variety of environmental estrogens prevalent in the western world. All of the chemicals that we face each day, combined with the added burden of phytoestrogens from soy, might be enough to push us over the edge.
However, if I can get “unscientific” for a moment, practically everyone would agree that it’s rare to see a particularly muscular Asian. Could the blame be ascribed to genetic factors, a difference in training methodologies, a difference in cultural priorities or, at least partly, a diet based on soy protein? I certainly don’t know.
I don’t know what the repercussions of the government’s newly found love of soy will be, either. Will it lead to increased infertility? A society of young men who are more female than male? A lack of vigor that’s indicative of reduced levels of testosterone?
Furthermore, I don’t know the repercussions of the fitness industry’s newfound love of soy. Will using soy proteins make it harder to put on muscle?
Again, I don’t know. I certainly think that more research needs to be done before soy, like another evil of Pandora’s nutritional box, is set loose upon the world.
I do know that I won’t use soy protein powders or eat any soy products other than an occasional bowl of Miso soup. Furthermore, I know that I won’t give my dog any dog foods that contain soy and, if I had children, I’d pack their lunch.
- Strauss L et al. **Genistein exerts estrogen-like effects in male mouse reproductive tract.**Mol Cell Endocrinol. 1998 Sep 25;144(1-2):83-93.
- Casanova M et al. Developmental effects of dietary phytoestrogens in Sprague-Dawley rats and interactions of genistein and diadzein with rat estrogen receptors alpha and beta in vitro. Toxicol Sci. 1999 Oct;51(2):236-44.
- Kumi-Diaka J et al. Cytotoxic potential of the phytochemical genistein isoflavone and certain environmental chemical compounds on testicular cells. Biol Cell. 1999 Sep;91(7):515-23.
- Anderson D et al. Effect of various genotoxins and reproductive toxins in human lymphocytes and sperm in Comet assay. Teratog Carcinog Mutagen. 1997;17(1):29-43.
- Hopert AC et al. Characterization of estrogenicity of phytoestrogens in an endometrial-derived experimental model. Environ Health Perspect. 1998 Sep;106(9):581-6.
- Setchell et al. Dietary Estrogens a probable cause of infertility and liver disease in captive cheetahs. Gasteroenterology. 1987 Aug;93(2):225-33.