Is Soy a Healthy Food?

endocrine disruptors genetically modified soybeans heart disease isoflavones linoleic acid phytoestrogens saturated fats soy soy elimination diet soy lecithin soy protein soybean oil thyroid gland unsaturated fats vegetable oils Apr 01, 2023

Soy is a controversial food item. On the one hand, soy-based foods are thought to be healthy. This is because they are common ingredients in plant-based diets, which are linked to several health benefits.^1,2 On the other hand, other studies have raised concerns about the negative effects of soy on health.³ In this article, we'll analyze the soy debate through the following topics:

Traditional consumption of soy in Asia
How soy is usually consumed in the West
Negative effects of soybean oil consumption
Unhealthy components of genetically modified (GM) soybeans
Soy as an endocrine disruptor

Let's now discuss each of these points so we can assess whether soy is a healthy food or not.

Traditional consumption of soy in Asia

People in Asia have consumed soy-based foods for centuries. Based on historical records, the use of soybeans as food started in China probably about 2,000 years ago. From China, soybeans spread to Japan and Southeast Asian countries. Soy foods are either fermented or unfermented. Traditionally, Asians consume the fermented forms like miso, natto, and tempeh.¹ Soy sauce, a fermented condiment, is widely used not just in Asia, but globally as well.^1,4

Statistics show that Asians have better overall health than Westerners do.⁵ This factor, together with the strong consumption of soy in Asia, contributes to the belief that soy is good for health.

How soy is usually consumed in the West

Over the past decades, vegetarian and vegan diets have become more popular in Western countries for ethical, ecological, and health reasons. Such plant-based diets regularly feature soy-based foods. This is because the protein quality and functional properties of soy make it suitable for producing meat and dairy alternatives.³ Thus, soy protein ingredients — mainly soy protein isolate, soy protein concentrate, and soy flour — are frequently used by the Western food industry.¹

In addition, soy is a major source of complex mixtures called lecithins. Lecithins are commonly used as emulsifiers in the food and drug industry. These emulsifiers are added to processed foods and medicines to prevent their ingredients from separating.^6,7

Soybean oil also plays a big role in the food supply in the West. In the United States, soybean oil accounts for over 50 percent of all domestic vegetable oil use.⁸ Restaurants and food manufacturers benefit from using soybean oil because the soy industry is subsidized by the U.S. government. This means that soybean oil is a cheap ingredient.

Negative effects of soybean oil consumption

The increased use of vegetable oils followed the release of dietary guidelines recommending against saturated fats like lard, tallow, and butter. Those guidelines were issued after saturated fat intake was linked to heart and blood vessel disease in the 1950s. This association has since been found to be spurious and the result of cherry-picking data.^1,9 Still, many people continue to avoid animal-based fats.

Vegetable oils like soybean oil contain unsaturated fats, mostly omega-6 polyunsaturated fatty acids (PUFA). The main omega-6 PUFA in vegetable oils is linoleic acid. However, more recent clinical evidence shows that linoleic acid promotes a stressful environment for cells. Such stress damages cellular parts, especially DNA. What's more, linoleic acid is linked to chronic, low-level inflammation and atherosclerosis (hardening of the blood vessels). For these reasons, linoleic acid from soybean oil and other vegetable oils — rather than saturated fats — increases the risk of heart and blood vessel disease.¹⁰

Unhealthy components of genetically modified (GM) soybeans

Most soybeans grown in the United States are genetically modified (GM).¹¹ The problem is, GM seed producers do not need to reveal exactly how they change the genetic material. This is why GM foods made of who-knows-what are sometimes called "Frankenfoods." Also, a study found that GM soy had poorer nutritional quality than conventional and organic soy. Specifically, GM soy had much lower levels of total protein, but higher amounts of linoleic acid.¹²

In that same study, GM soy was found to contain high residues of glyphosate. This chemical is used to kill weeds and grasses. GM soy also had high levels of aminomethylphosphonic acid (AMPA), which is produced when soil microbes break down glyphosate. In contrast, glyphosate and AMPA were absent in conventional and organic soy.¹² Glyphosate exposure has been linked to multiple health issues. These conditions include abnormal heartbeat, low blood pressure, mental relapse, kidney failure, and breathing problems. Glyphosate was reported to cause problems during pregnancy as well. At the cellular level, the chemical is known to damage the cell membrane and impair the function of the mitochondria (the part of the cell that produces energy from the food we eat).¹³

Soy as an endocrine disruptor

Endocrine disruptors are substances that change the normal function of the endocrine system. The endocrine system is made up of glands. These organs produce and release hormones that control a wide variety of processes in the body. By altering the said processes, endocrine disruptors cause harmful effects on health.¹⁴

In particular, the thyroid gland is very important because it secretes hormones affecting almost all cells. When endocrine disruptors throw thyroid hormones out of whack, numerous health problems arise. For example, since the thyroid controls metabolism, changes in the thyroid can cause weight gain or loss. The same gland regulates body temperature. This means that people can feel too hot or too cold when their thyroid function is disrupted. Even worse, exposure to endocrine disruptors is linked to thyroid cancer.^15,16

Phytoestrogens are among the substances known to disrupt the endocrine system. Soy is the main dary source of these natural plant chemicals, which are sometimes called isoflavones. For this reason, soy can be considered an endocrine disruptor.^17,18

Soy isoflavones not only harm the thyroid, but also raise the body's estrogen levels. This happens because isoflavones are similar in structure to the human sex hormone estrogen. Therefore, they can mimic the actions of estrogen on target organs.¹⁹ Having too much estrogen in the body comes with a whole other array of health risks.

Conclusion

Soy protein, soy lecithins, and/or soybean oil can be found in virtually all processed and prepared foods today. Such soy-based foods are the main source of isoflavones. These phytoestrogens are endocrine disruptors that harm thyroid function and cause excessive estrogen levels. Having too much estrogen is linked to cancer, stroke and blood clots, heart and blood vessel disorders, and even snoring.

So, is soy a healthy food? The bulk of the evidence suggests no. If you have any of the issues listed above, especially snoring, you may benefit from a soy elimination diet.

Check out the proven six-week program The Snoring Diet Solution to learn how you can stop snoring naturally and permanently in as little as two weeks.

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