Soy is regularly touted as the poster child of a healthy diet and healthy living, especially amongst vegans and vegetarians looking for a protein substitute, but is it as healthy as it is claimed to be? Both soy and flax contain something called phytoestrogens, which are a type of phytochemical that have estrogen-like effects on the body. The two major types of phytoestrogens are isoflavones and lignans. Phytoestrogens are weak estrogens that mimic estradiol, the main estrogen found in the human body, and bind to our estrogen receptors.
Why are they a problem?
Well, for men, excess estrogen can cause a feminising effect on the body. Besides developing an affinity for Bridget Jones’s Diary and Must Love Dogs, too much estrogen can lead to the dreaded man boob syndrome. This also happens to a lot of bodybuilders and steroid users who don’t know what they’re doing. Basically, when you take anabolic steroids, you boost your testosterone levels. This comes at a price though, as some of the excess testosterone aromatizes, or converts, to estrogen. Now smart steroid users, if there is such a thing, will stack their anabolics with an anti-estrogen, to prevent this from happening. Anyway, enough about bodybuilders, can the same effect happen with weak estrogens too?
Where do we find phyto-estrogens?
The list of foods that contain phytoestrogens include soy beans and any soy based products, flaxseeds (linseed), sesame seeds, wheat, berries, oats, barley, dried beans, lentils, rice, alfalfa, mung beans, apples and carrots. The two main dietary sources though are soy and flaxseeds, which both contain very high levels of phytoestrogens and have come under the spotlight recently. Soy’s health benefits are normally attributed to its isoflavones, genistein and daidzein, whilst flax’s phytoestrogens come in the form of lignans.
Claimed Health Benefits
Unless you’ve been living under a rock, you’ll know that both soy and flax have been highly touted for their health benefits. The isoflavones in soy are said to improve bone health and may help to reduce osteoporosis risk. The isoflavone genistein seems to inhibit bone breakdown and may a have similar effect to estrogen in maintaining bone tissue. Soy’s isoflavones are also said to relieve menopausal symptoms, reduce the risk for heart disease and prevent certain cancers such as breast cancer, prostate cancer and colon cancer.
Additionally, the lignans in flax are powerful anti-oxidants and have been said to reduce the incidence of heart disease, cancer, and kidney disease. That’s quite an impressive list of benefits, but what are they not telling us?
Soy’s Dark Side
Of all the dieticians, nutritionalists, books, websites and even the FDA singing the praises of soy as a wonder health food, there is a growing number of dissidents who question the spurious health claims of soy. They even go so far as to say that soy is unhealthy, especially for men. The debate on phytoestrogens has become very heated and polarised; it seems people are either pro-soy and think it’s a miracle cure-all food or people are anti-soy and think it’s responsible for introducing to much estrogen into the diet. The problem lies with the phytoestrogens and the effect on the male hormone profile.
Phytoestrogens can work in two ways. Firstly, they can bind to your estrogen receptor sites, which in turn attach to DNA regions of genes that lead to protein transcription, in effect acting as a real estrogen. The other way in which they work is simply to bind to these receptor sites and sit there, preventing real estrogen from getting its parking space and initiating transcription.
The pro soy crowd obviously argues that the phytoestrogens will block the receptors and prevent the more powerful estradiol from binding to those receptors. Thus, they argue that phytoestrogens in fact lower estrogen levels, which is why it is said to have anti-cancer properties. That is a fair point, but if somebody, especially a man, had low estrogen levels to begin with, the weak estrogen will still bind to the receptors and yield a net estrogen increase, albeit a rather weak one. On the flip side, if the weak estrogens are blocking the strong estrogens this could yield a net estrogen decrease. Unfortunately, some studies have shown that genistein and daidzein, soy’s phytochemicals, appear to have a significant estrogenic effect. It has been shown that genistein does activate transcription to a significant degree after binding to the receptors and therefore will cause growth of tissues.
Dr Kaayla T. Daniels has written a chilling book called The whole Soy Story in which she disputes most of soy’s health claims and points to health problems amongst her female clients, as well as men.
The Whole Soy Story: Dr Kaayla T. Daniels.
She frequently cites hypothyroidism as the main problem for women on high soy diets, which can lead to loss of sexual drive, weight gain, chronic fatigue, poor skin and hair loss. Vegans and vegetarian are most at risk because they tend to consume far more soy than the average person to make up for their lack of protein, in the belief that it is a miracle food. Dr Kaayla also goes on to attack the FDA and the soy industry for fabricating soy’s health benefits and covering up any health problems. In fact, the FDA approved health claim that soy reduces the risk of heart disease stems from only one study funded by the soy industry itself, hardly objective science. Additionally, a large portion of research into soy is funded by the industry itself. Sound like a conspiracy theory? Dr Daniels thinks so.
Because soy is so cheap to manufacture, it is insidiously finding its way into most supermarket-packaged foods from ice cream to canned tuna to meat burgers. In the United States, soy can be found in 60% of supermarket products. Soy allergy is also increasing and can be likened to peanut allergies in severity. It is now listed in the top eight food allergens.
My main problem with soy is the way that it is being processed. The traditional Asian soy products like Meso and Tempeh are fermented soy bean products and are a lot healthier than the soy that we are being sold today. Textured vegetable protein (the stuff you will find in veggie burgers), bouillon or vegetable oil are highly processed soy products that have been exposed to many chemicals, extreme manufacturing processes and high temperatures in order to create something that is palatable. There is nothing natural about these products and this is a huge concern to me with regards to phytoestrogens. When the difference between food and medicine is disregarded, when phytoestrogens are isolated and concentrated and sold to us in pills and candy bars, then the equation changes. Under these conditions, phytoestrogens become powerful hormones, quite capable of promoting cancer. Apart from the risk of gynecomastia, aka bitch tits, men are also at risk of lower androgen levels – a spanner in the works for any guy trying to build lean body mass.
Whilst Dr. Daniel’s views are cause for concern, I do find her to be somewhat extremist and I like to tow a more moderate line on such polarised issues. Leading sports nutritionalist and author of Precision Nutrition, Dr. John Berardi, is equally pragmatic in his approach to soy and phytoestrogens. He finds it rather ironic that the majorities of people in the health and fitness community, especially strength athletes, bash soy because of its phytoestrogens, but sing flaxseeds praises and consume it in large quantities. His recommendation is that flax might not be harmful in moderation, but that men should not consume too much due to the potential link to prostate cancer. He is understandably a lot more concerned with environmental xenoestrogens.
Controversy over Flaxseed
The Lignans in Flax don’t seem to activate transcription in the estrogen receptors to the same degree as genistein, although there appears to be some transcription and there is some evidence that high intakes of flax seed oil may have a negative effect on prostate health.
The Humble Flax Seed. Photo by Bdevel
There has been a lot of press recently advising men to stop supplementing with flax oil. Personally, I think moderation is the key and the health benefits of consuming Omega 3 fatty acids far outweigh any questionable harm from lignans. In fact, ground flax seeds made it into my 10 Super Foods You Should Be Eating
I’ve tried to present both sides of the phytoestrogens debate, the pros and the cons. I do not like to polarize myself on such issues and try to remain open minded. However, in light of all the research I’ve done, I’d have to conclude that I wouldn’t recommend most soy products as a health food and feel that in its processed form it should be avoided, especially by men. Moderate use of fermented soybean products, in my opinion, will not pose a health risk and may even provide some benefit. The problem arises when health conscious people replace almost all of their complete protein sources with soy products. Although soy protein is a complete protein, I feel that it is still inferior to Whey, Casein and egg protein and therefore see no reason to actively include it in my diet.
With regards to flaxseeds, the lignans are also estrogenic, but not as potent as the soy isoflavones, nor is it heavily processed for consumption. Additionally, flaxseeds are an excellent source of the Omega 3’s that is so lacking in the modern western diet.
As far as the whole estrogen debate goes, I think we should be a lot more concerned with environmental xenoestrogens, but that’s a topic for another article.