The Truth About Soy

By: Sara Shipley, University of Central Oklahoma nutrition student

I have recently been working with a young woman who has decided to take up a vegetarian diet, for personal reasons. Interestingly, when we came to the topic of dairy, she waivered, but had decided to drink almond milk because she had heard so many controversial things about soy and soymilk. Before recommending anything- I wanted to get all my facts straight about the soy controversy.

Anywhere you look- from media sources, online reviews, diet books, to government publications, you are going to find countless claims about soy. Some are touting the natural benefits, while other sources warn of the harmful effects soy has in the diet. There are so many myths, it all seems impossible to ignore.

A handful of negative claims about soy:

  • It causes thyroid problems
  • It increases cancer risk and heart disease
  • It causes fertility problems
  • It affects male sperm quality
  • It increases estrogen levels
  • It is unsafe for pregnant women
  • It is an allergen
  • It interferes with mineral absorption

All of the claims are controversial, but what is the truth? Research studies are mixed however according to Virginia Messina, MPH, RD and Mark Messina, PhD,  “it is important to recognize some important facts about scientific research. It’s true that there have been studies showing negative effects associated with soy consumption. But it is a rare situation where every single study on a subject is in agreement. There are always a few that sit in direct contrast to the majority of the studies. So it is never a good idea to suggest broad conclusions or recommendations based on one or two studies. By picking and choosing individual studies carefully enough, you can prove just about anything you would like about nutrition. That’s why health experts look at all the research and pay attention to the totality of the evidence, not just to a few studies. Many of the studies that have concluded that soy is unhealthful have used animals as subjects. Drawing conclusions about human health from animal research can be very misleading.”

I couldn’t agree more with the phrase “by picking and choosing…you can prove just about anything you would like about nutrition.” That gives anyone free reign to make health claims based on research, regardless of the validity or legitimacy of a study. Registered dietitians are the experts in food and nutrition, so trust only those sources for the truth behind nutrition information.

For more than 11 years, the FDA has supported the health claim that soy can fight heart disease and contributes to decreased LDL cholesterol levels. The United Soybean Board consists of a team of nutrition experts that have cleared up the controversy about soy. Recent research refutes so many of the myths listed above and advises soy as a healthy, safe component to a balanced diet. Low in saturated fat, soy contributes to heart health, as noted with the FDA stamp of approval. Soy has been attributed to reducing the risk for breast cancer and preventing prostate cancer. There is no scientific evidence that soy lowers testosterone levels or increases estrogen levels in males. There is no scientific evidence that soy is harmful to pregnant women. Although all soy is NOT the same, soybeans are virtuous sources of protein, fiber, polyunsaturated fat and a list of minerals, including calcium. In fact, this plant protein is equivalent to animal protein sources as it contains all nine essential amino acids, which the body cannot produce and therefore, we must consume these in our diet. Soy foods are also a good source of dietary fiber, which have great benefits to your health (lower cholesterol, increase digestive health and lower risk of heart problems).

I wanted to be thorough in my quest for the truth about soy, without subjective information from soy companies. Each of the sources I found most reputable had highly qualified experts- dietitians and physicians who know the science behind soy. If you are interested further- check out any of these websites. (Jack Norris RD has a thorough article on soy, which substantiates the research, both good and bad.)

http://www.soyconnection.com/soyfoods/soyfoods_directory.php

http://www.soynutrition.com/

http://jacknorrisrd.com/?p=1778

So, other than a source of protein for vegetarians, why would I recommend soy foods? This legume is chock full of nutrients every rounded diet- including the athlete needs: complete protein, fiber, polyunsaturated fats, and calcium. Not to mention- have you ever tried vanilla or chocolate soymilk? It tastes pretty darn good and adds much more creaminess to your bowl of cereal or cup of coffee than watery skim milk.

So, I advised soy milk to my vegetarian friend. The benefits to soy are unparalleled for her diet.

Do you ever drink soy milk or have you ever tried soy foods? What is your perception on soy and your health?