Soy & Its Effects on the Body

The soybean is a controversial little thing. Some people swear by the nutritional benefits this legume has to offer, whereas others warn that it may cause more harm than good to the human body. So, is soy harmful or healthy? Let's find out!

What Is Soy?

The soybean, originally from Southeast Asia, is a legume belonging to the pea family. Soybeans have been around for a long time. Around 1100 BC, Chinese farmers began to domesticate these humble beans because of their nutritional value.

Soybeans contain complete protein. They also contain each of the nine essential amino acids which the body can't produce on its own, meaning that you need to consume them on a daily basis. Soy is also a great source of natural antioxidants called polyphenols. On top of that, it contains vitamin C, folate, thiamin, potassium, phosphorus, magnesium, iron, and calcium.

There are many different varieties of soybeans, but the three most common types are green, yellow, and black soybeans. Green soybeans are making a big comeback in the form of the popular edamame beans. Black soybeans are often simmered or fermented. Yellow soybeans are probably the most common and mass-produced because they are used to make other food products like tofu, soy milk, tamari, and tempeh.

How Is Soy Processed for Food and Supplements

Soybeans are incredibly versatile. You can cook, steam, simmer and ferment them before eating. You can drink them in the form of soy milk, or eat them in the processed forms of tofu, tempeh, or tamari. You can even use soy oil to cook with.

The value of soy's plant-based protein content has not been lost on people in the supplements industry. It is a very popular ingredient in many protein powders and other supplements.

What Are the Effects of Soy on the Body

We know that soy is packed with essential amino acids and other vitamins and minerals that carry great nutritional benefits. Why then are there so many people who question whether soy is healthy or harmful? We'll take a look at both sides of the argument.

The Benefits of Soy

• Might Lower Cholesterol: There are studies that suggest that adding soy to your diet can help to lower the "bad" cholesterol LDL and increase the "good" cholesterol HDL.
• Might Improve Cardiovascular Health: We already know that adding legumes to our diets can help in lowering our risk of cardiovascular disease. Studies suggest that the isoflavones found in soy can reduce the elasticity of blood vessels, as well as reduce blood vessel inflammation. Some studies even suggest that adding soy foods to your diet can reduce your chances of dying from cardiovascular disease by anything up to 15%.
• Might Lower Blood Pressure: Soybeans and soy products contain an amino acid called arginine. This amino acid is thought to aid in balancing blood pressure levels. Soybeans also contain compounds called isoflavones, which are believed to help lower high blood pressure.
• Might Lower Blood Sugar: Studies suggest that the isoflavones found on soybeans and soy products may reduce insulin levels, as well as blood sugar levels in women who are undergoing menopause. The same study suggests that the isoflavones found on soy aid in lowering insulin resistance. Left unaddressed, insulin resistance can lead to type 2 diabetes.
• Might Improve Fertility in Women: One study suggested that women who added high levels of soy isoflavones to their diets had a higher chance of successfully giving birth after undergoing fertility treatments.
• Soy Effects Estrogen Levels: We've mentioned isoflavones a fair amount, but what are they? Isoflavones are also known as phytoestrogens, or, simply put, plant estrogens. These compounds mimic estrogen and are able to bind to the estrogen receptors in the human body. This is great for women during menopause. Menopause symptoms such as hot flashes and fatigue are caused by lower estrogen levels in menopausal women. There are studies that suggest that soy isoflavones can help to reduce menopause symptoms such as hot flashes and fatigue by mimicking estrogen.
• Might Improve Bone Health During Menopause: Osteoporosis, a state of weakened or brittle bones, is the result of calcium deficiency in the bones caused by lowered estrogen levels during menopause. There are studies that suggest that an increased intake of soy isoflavones can improve the bone health of menopausal women.
• Might Reduce the Risk Certain Cancers: There are many studies that link high intakes of soy to reduced risk in cancers such as breast cancer, endometrial cancer, digestive tract cancers, and prostate cancer.

Is Soy Bad for You? Common Concerns About Soy

As we've mentioned, soy is a controversial topic. Although many believe in soy's beneficial effects on the human body, there are also many who are concerned that soy's impact is more harmful than beneficial.

Some believe that high intakes of soy may impair thyroid function, increase the risk of certain cancers, and that soy affects testosterone production. Some people even believe that soy intake is linked to kidney stones and kidney failure. There is also much debate about the safety of soy used in formula for babies. Many believe that giving formula rich in soy to newborns can negatively impact their development.

Words like "might", "may", "believed to", or "suggest" are commonly added to claims about soy's effects on the body. This is because there simply isn't enough strong science to substantiate the claims. Much more research is needed to confirm or deny many of the concerns surrounding soy intake.

The general rule of thumb is that as part of a well-balanced diet, soy can have a positive and beneficial impact on the body. As with anything we add to our diets, we need to be aware that too much of a good thing can have a harmful effect on our bodies.

Nina Kulenkampff is a freelance copywriter and editor based in South Africa. She is passionate about the written word and loves diving deep into research on any given topic. When not at her desk you will find her deeply absorbed in a book or out on a hike in the great outdoors.