How healthy is Soy?

In 1992 the soy industry was a  fringe part of the health food market that took in about 300 million. By 2007, it had grown into a 4 billion dollar giant. Since 2000, the food industry has introduced over 2700 new foods with soy as an ingredient and according to research on consumers’ attitudes toward food, 85% of American consumers perceive soy products to be healthy.  These things make soy look like a winner for both food companies and consumers, but recent research has raised some questions as to soy’s benefits and has many health and nutrition experts questioning their views on soy. So what is the truth about Soy? Is it a true health food or a creation of the food industry that should be avoided. Here is some information from recent research that may make you think twice about soy  so you can decide if it is right for you.

  • A study involving Japanese-American men showed those that ate the most tofu during midlife increased their risk of later developing Alzheimer’s disease by up to 2.4 times. When compared to men who never consume tofu, men who ate it at least twice per week had more cognitive impairment and actually had increased brain shrinkage.
  • Excessive soy ingestion might suppress thyroid function in healthy people (this can lead to a depressed metabolism and to weight gain).
  • Soy phytoestrogens can disrupt endocrine function and may contribute to infertility. Some studies show men have a decreased sperm count from continued soy consumption.
  • Women who consumed soy phytoestrogens (for up to 5 years)  had an increased occurrence of endometrial hyperplasia.
  • Men who consumed large amounts of soy had higher rates of stomach cancer. Both men and women who consumed lots of soy had more colorectal cancer.
  • Infants who drank soy milk and consumed soy products were nearly three times as likely to develop  peanut allergies later in life.

A great link to these peer reviewed studies and many more can be found at

Which ones are unhealthy?

The unhealthy forms of soy are actually the ones that are most commonly found on the market today. Soy tofu, soy milk, soy protein and soy oil (commonly labeled as “vegetable oil”) all have negative health aspects and should be avoided. Modern food processing techniques are a major reason why these forms of soy are so unhealthy.

Is any form of soy healthy?

Fermented forms of soy including natto, tempeh, miso and soy sauce are actually healthy for you since the fermentation process negates many of the unhealthy aspects of soy. Traditional processing techniques of soy took months if not years to accomplish, not like many foods today which are processed very quickly using methods that strip nutrients or use unhealthy chemicals.

I don’t need to worry about soy, I don’t eat tofu or drink soy milk, right?

Think again, soy is found in the majority of food products in the supermarket including crackers, packaged foods, conditments, and many more. Usually it is found as soy protein isolate or soy oil (sometimes labeled as simply vegetable oil) in these foods.

Why do so many Americans believe soy is a health food and if soy is not healthy for us, why have we been lead to believe it is. Those are questions beyond the scope of this article and are dealt with in amazing depth in Dr. Kaayla Daniel’s excellent book The Whole Soy Story or her website Two other great sites for information on soy are and