So for me this is really a personal topic. I've gone through just about every diet you can think of and for a long while I got a lot of my protein from soy products. At the time I was experiencing a lot of gastrointestinal dysfunction and I just assumed it was because I increased my intake of beans and fiber and of course that may have been something to do with it however in retrospect knowing what I know now I believe it was the soy I was eating. Now I didn't know very much about soy at the time, and unfortunately most of what I was eating with tofu. And just a minute I'll explain why that was a grave mistake.
Let me back up a bit and say that there is an endless supply of independently published human research on the value of soy foods, and soy isoflavones. The studies go back for decades. If you start researching different diseases and conditions like cancers, menopause, prostate health, heart and artery disease, we see the studies on isoflavones helping and in some cases reversing these conditions. This is a undisputed fact and it really should at least peak interest in skeptics. Articles published in the Journal of Nutrition (v 131, 2001 and v 132, 2002) on the value of soy isoflavones for heart and artery health concluded, "These data suggest a protective role for dietary soy intake against CVD in post-menopausal women." The women (several hundred) with the highest intake of isoflavones had lower body mass indexes, lower body fat, smaller waists, and much lower insulin levels. High insulin leads to diabetes, heart disease, cancers, and other illnesses. A second study from the famous Framingham Study studied 939 women and stated, "High intake of phytoestrogens in postmenopausal women appears to be associated with a favorable metabolic, cardiovascular risk profile." In fact, they found a massive 34% difference in CHD disease between women with low soy intake and high soy intake. 34% folks, I think that is significant. Let's also take a quick look at cholesterol and soy. There have been many studies published on the value of soy supplementation for lowering total cholesterol and LDL (the bad kind) cholesterol. Soy added to the diet also raises HDL (the good kind) cholesterol levels. All this without any change in diet or exercise. In fact what are the benefits I found when I add soy to my own diet was a huge drop in cholesterol my total cholesterol was about 300 after six months of eating soy as a major protein source, and of course some other changes like adding more vegetables my total cholesterol dropped to 180.
Still there is a lot of the anti-soy messaging being promoted. When I researched this I found a strong trail that led back to the America Dairy Association (ADA), obviously they are bias. Interestingly one of the charges made by the ADA against soy is that it will alter hormone levels, but this is untrue soy is not a “phytoestrogen” as it is completely and totally unrelated to any kind of estrogen. Hormones only exist in animals and not plants. Soy has Isoflavones which are PLANT PIGMENTS, not phytoestrogens. Our estrogen receptors will not accept soy isoflavones. No one else on earth is going to tell you that there is no such thing as "phytoestrogens"... but now you know, I have done the research. More interesting is that drinking beer with hops is one of the strongest sources of feminization in men. Hops contain 8-prenylnaringenin (8-PN), which binds to alpha receptors that are responsible for triggering cell growth in tissues affected. Conversely, soy binds to beta receptors that are responsible for retarding the cell growth response. In other words, soy has anti-growth effects whereas hops tell tissues to grow. This is one reason why heavy beer drinking men develop so-called man-boobs, gynecomastia. I say, very interesting, don't you think?
Now listen, all is not rainbows and sunshine for soy users. You see soy is a significant cash crop in this country and it is grown in massive amounts to feed livestock. Yup, your steak burger was raised on soy but not the friendly healthy type, no instead this is GMO (genetically modified) and grown with many nasty chemicals to produce optimal yields. Hmm, consider that the ADA is telling you not to eat or drink soy products, but it is buying these same products, the heavily poisoned, GMO version and feeding it to the animals they are selling you to eat and drink (cows milk). Now that's really screwed up isn't it? I cannot make this stuff up, it's that unbelievable.
So now here is the take away, first make sure all your soy foods are marked “organic” or “non-GMO”, so you avoid GMO soy. Personally, I enjoy organic plain soy milk and Tempeh almost daily, and by the way, I have full blood work done twice a year, and my hormone levels are perfectly balanced, in fact, my estradiol is <5 (which is actually very low), so no man boobs in my future. Of course, I also do not drink beer... just saying. Since I started eating organic soy products my LDL cholesterol have come way down and my HDL cholesterol has come up. This is a good thing. Also, my blood pressure has come under control without medications (I tend to run a hypertension profile), and all my numbers show I am much more healthy. Of course, I am not eating as much red meat and other animal products because of the soy substitution so all these are considered factors, like the fact I am drinking green tea. Still the overall vibe for soy is positive, and I am always recommending it to patients, as long as they do not have adverse reactions to it. You see there is not one size fits all, and I acknowledge some people just don't do well on soy... or dairy, or fish or nuts. So as always, we have to make smart decisions based on our individual biochemistry, but when you hear that eating soy causes terrible illness like thyroid conditions, diabetes, nutritional deficiencies, pancreatic problems, endocrine disorders, brain dysfunction, and even various cancers, this is too ridiculous to comment on. Many people, however, take such ravings seriously. When you try to find proof of these allegations, they start to evaporate. If you actually hunt down any of these so-called "studies" and look at them in detail, you'll see they have no validity at all. If you want to improve your health, just drink soy milk and use it in cooking or you can take a 40 mg isoflavone capsule daily. This will benefit you in ways we haven't even discovered yet. New studies are being done all the time in clinics around the world. Soy is good stuff, science has proven it, just make sure you eat organic and fermented if possible.