In the rush to embrace soy foods some inconvenient facts are becoming more apparent. In particular soy foods have are been promoted as a safe alternative protein source for men.

In 2007 , scientists at the Harvard School of Public Health concluded ” that higher intake of soy foods and soy isoflavones is associated with lower sperm concentration.”  This conclusion was reached after an experiment they conducted showed that men eating just  half cup of soy foods  per day  resulted in 41 million fewer sperm per milliliter than men not consuming soy in their study.

I’ve addressed some gross inaccuracies made by Dr. Ian Smith in the interview above:

So called natural soy foods  he claims are safer (soy milk, edamame, and tofu). In reality these are the foods that provided  high levels of the sperm-reducing isoflavones. Especially if you are a vegan or vegetarian.  The real take home message is to avoid them period! http://www.westonaprice.org/soy/dangersisoflavones.html

Asian have been eating fermented soy foods in relatively small amounts.  Mostly in the form of condiments as soy sauce.  Also this was never the main source of food only in times of famine or in isolated places like their monasteries.  Soy was also eaten in the context of a traditional diet that had high levels of minerals which offsets soy’s negative impact. Take home message: Americans overeat soy foods and Asians never had the variety of fake soy foods as we have access to. Avoid them!

Soy lowers cholesterol:  This claim approved by the FDA “relied largely on a 1995 meta-analysis by Dr. James Anderson, sponsored by Soy Protein International and published in the New England Journal of Medicine”   Meta-analysis has come under fire for potentially supporting very unscientific claims . “Researchers substituting meta-analysis for more rigorous trials risk making faulty assumptions and indulging in creative accounting,” says Sir John Scott, President of the Royal Society of New Zealand.  Ronald M. Krauss, MD calls research that ties soy to lower levels of  cholesterol  “incredibly immature,” who is Senior Scientist Director, Atherosclerosis Research at Children’s Hospital Oakland Research Institute. Take home message: Don’t believe the hype!

Dr. Smith claims that 25-50 grams of soy is considered healthy.  Well research shows that  just 30 grams of soy daily resulted in significant suppression of thyroid function as measured by the rise of thyroid stimulating hormone. Y.Ishizuki, et al, “The effects on the thyroid gland of soybeans administered experimentally in healthy subjects”Nippon Naibunpi Gakkai Zasshi 1991,767:622-629

Take home message: Keep your soy consumption to a minimum if at all.

Soy’s negative effects are not limited to sperm counts.  In a study called ” Impact of Exposure to Endocrine Disruptors in utero and in childhood on Adult Reproduction”  the authors found that high levels of the genistein ( the plant estrogen found in soy) had feminizing effects on men.  This included breast development, and reduced sex drive due to a decrease in androgen’s.

The answer to this marketing hype is a dose of real food.  Food that humans have thrived on for millennia, grass-fed beef, free range chickens, eggs, butter, raw milk and a variety of produce.

For more info see:

http://westonaprice.org/soy/index.html

http://www.westonaprice.org/soy/dangersisoflavones.html