Shulman Weight Loss Blog

Soy has been researched quite extensively with a variety of conclusions being drawn.

Q: So…what’s the deal with soy?

Soy has been researched quite extensively with a variety of conclusions being drawn. Thus, making your way thru the soy controversy can be quite confusing, as the press received has been mixed. As a general rule and as far as health and nutrition go, it is never a good idea to base recommendations on one or two studies. I have come to realize, if you pick and chose research carefully enough, you can prove just about anything you like. The best approach that offers the least amount of bias is to review the entire body of research and then draw your own conclusion. Now, I realize you do not have the time to start pouring over all the soy researched double blind studies to make a decision, so allow me to summarize for you what the findings show. Benefits of soy:
  • According to the Food and Drug Association (FDA), soy foods can help to lower the “bad” cholesterol (LDL) and is good for heart health.
  • Soy contains an impressive amount of isoflavones (phytochenicals found in plants) which have been shown to slow the relief of certain menopausal symptoms, offer cancer protection, slows and may reverse osteoporosis and reduces the risks of heart disease.
  • People often use soy as a healthier choice option (i.e. instead of eating red meat), so in that regard it is also beneficial.
  • Moderate soy consumption appears to reduce most types of cancers with the exception of estrogen dominant breast cancers being unknown (see below).
Negatives of soy:
  • A very large percentage of soy is genetically modified (over 90%) and is heavily sprayed with herbicides and pesticides.
  • Soybeans have an anti-nutrient called “phytic acid” which can block the absorption of certain minerals such as magnesium, calcium, iron and zinc.
  • The isoflavones in soy have a very weak phytoestrogenic effect (i.e. they mimic estrogen). While a growing body of research shows that eating a healthy diet that includes soy foods protects and lowers the risk of breast cancer, the research is not clear for estrogen positive cancers.
  • Similar to dairy products, in some individuals, soy can cause allergenic reactions.
Tips to eat soy in a healthy manner are:
  • Always choose organic soy products
  • Choose fermented soy products. After a long fermentation process, the phytic acid levels of soy are reduced significantly. Examples of fermented soy products are:

√Tempeh– A fermented soybean cake with a nutty flavor. Add to stir-fries or eat as a “tempeh” burger.

√Miso – A fermented soybean paste with a salty, buttery taste. Perfect for when making soup broths and readily available in health food stores.

√Tamari (or Shoyu), a fermented soy sauce that is very flavorful and salty

  • For other soy options, I recommend trying to consume products that have undergone as little processing as possible (i.e. organic edamame).  I am not an advocate of making highly processed soy meats, burgers, milk, baby formula etc. as a regular part of your dietary intake.
  • If you do have an estrogen positive breast cancer (ER+), limit your soy intake to 2-3 selections of fermented soy products per week. The National Cancer Institute and the American Cancer Society recommend that breast cancer survivors can safely consume moderate amounts of soy foods (a few servings per week).
Lastly, I am frequently asked the question, “Is soy safe for males to eat because of its weak estrogen like effect?” Human studies have found that males who consume soy have had no changes in sperm count, quality or motility. Studies have also shown that soy isoflavones have no effect on circulating levels of testosterone or other reproductive hormones.

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