Soy: Is It Healthy or Not? What the Experts Say
© 2018 Health Realization, Inc. Updated

Soy is one of the most widely grown, and widely studied (over 5,000 research studies on soy exist) legumes in the world. Here in the United States, you are likely familiar with soy in the form of soymilk, soy burgers, soy ice cream and the myriad of other processed soy products that claim to be ultra healthy.

In truth, studies have shown that certain forms of soy can help to:

• Regulate blood sugar and blood pressure

• Prevent colon, breast, and prostate cancers

• Prevent atherosclerosis (hardening of the arteries)

• Prevent hip fractures in post-menopausal women

Of course, soy wasn't always as popular as it is today. Soy foods have traditionally been considered a "peasant" food, and then a "hippie" food -- not something that the average grocery shopper would even consider eating, let alone purposely seek out.

Yet from 1992 to 2006, soy food sales have increased from $300 million to $3.9 billion, according to the Soyfoods Association of North America.

A large part of this increase came when the U.S. Food and Drug Administration approved a health claim for soy foods back in 1999 that said:

"Diets low in saturated fat and cholesterol that include 25 grams of soy protein a day may reduce the risk of heart disease."

Soon after, Americans were clamoring to get their hands on soy, in just about every form imaginable. But is it truly healthy?

There is No Recommended Daily Amount of Soy Products

Despite findings that soy is good for your heart and your bones, and may help to prevent cancer, no public health organization in the United States has recommended a daily intake of soy products. Not the National Cancer Institute, not the American Heart Association and not the American Dietetics Association.

It seems that there is still a lot of conflicting evidence on soy's impacts on your body, particularly in the way it is consumed today: processed.

Traditionally, soy in Asian cultures was fermented before eating. This not only makes the beans more digestible, it increases their nutritive properties while decreasing the presence of phytates, which prevent the absorption of minerals including calcium, magnesium, iron and zinc.

Meanwhile, these cultures ate soy in much smaller quantities (about 2 ounces a day) than Americans now eat soy. If you have a glass of soymilk, you are already drinking more soy than traditional cultures ate in a day. If you add to that a soy burger and some soy ice cream, you are eating an extreme amount of soy, the likes of which has never been consumed in history.

Says Dr. Kaayla Daniel, author of "The Whole Soy Story":

"Unlike in Asia where people eat small amounts of whole soybean products, western food processors separate the soybean into two golden commodities--protein and oil. There's nothing safe or natural about this.

Today's high-tech processing methods not only fail to remove the anti-nutrients and toxins that are naturally present in soybeans but leave toxic and carcinogenic residues created by the high temperatures, high pressure, alkali and acid baths and petroleum solvents."

In fact, processed soy foods like soymilk, soy meat products, soy ice cream, soy energy bars, etc., have been linked to:

• Malnutrition

• Digestive problems

• Thyroid dysfunction

• Cognitive decline

• Reproductive disorders

• Immune system breakdowns

• Heart disease

• Cancer

Further, soybeans are one of the most common genetically modified crops grown in the United States, and they are one of the top eight most allergenic foods.

Soy Isoflavones: A Double-Edged Sword?

Another concern about soy foods has to do with soy isoflavones, which are phytoestrogens, a weak form of estrogen that could have a drug-like effect in your body. It is a controversial issue, and some studies suggest that high isoflavone levels might actually increase the risk of cancer, particularly breast cancer.

Daniel Sheehan, Ph.D., director of the Estrogen Knowledge Base Program at the FDA's National Center for Toxicological Research, says isoflavones should be consumed "cautiously."

He says, "While isoflavones may have beneficial effects at some ages or circumstances, this cannot be assumed to be true at all ages. Isoflavones are like other estrogens in that they are two-edged swords, conferring both benefits and risks."

Which Soy Products ARE Healthy?

It seems the key to avoiding such health risks when it comes to soy is to stick with only unprocessed varieties.

In fact, a study in the June 2004 issue of Carcinogenesis found that processed soy products and supplements have a significantly lower ability to prevent cancer, and may actually stimulate the growth of pre-existing estrogen-dependent breast tumors, compared with whole soy foods.

"These partially purified isoflavone-containing products may not have the same health benefits as whole soy foods," said William G. Helferich, professor of food science and human nutrition at the University of Illinois at Urbana-Champaign and one of the study's lead authors.

The researchers suggested that it may be wise to avoid processed soy products and supplements that contain isoflavones in more purified forms, which is how many Americans consume soy.

Instead, they said to choose minimally processed whole soy foods.

So if you're looking for a healthy way to eat and enjoy soy, most experts agree that the following are truly healthy soy options:

• Edamame

• Whole soy flour

• Natto (fermented soybeans)

• Miso (fermented soybean paste)

• Tempeh (fermented soybean cake)

• Naturally fermented soy sauce 

Sources

Soyfoods Association of North America

The World's Healthiest Foods