7 Myths About Soya Protein - Busted by Science

We usually eat something either because we love the taste or because it’s good for our health. But soya foods often divide people. Some eat them for the protein, while others stay away, thinking they might not be safe.

Soya comes from soybeans, a type of legume rich in protein, fiber, and essential nutrients. It’s processed in different ways to make foods like tofu, soya milk, nuggets, flour, and protein isolates. Together, these soya varieties have some of the highest protein content compared to dal and paneer.

Yet, soya protein often receives polarizing views. Perhaps that’s why we haven’t been able to recognize and appreciate its nutritional value fully. But not anymore. This article clears the air around soya protein myths, backed by scientific studies. Keep reading!

What are the Myths Related to Soya Protein?

Your nutritionist might tell you to include soya in your meals, but a random Instagram reel might warn you against it. Does this sound familiar? If yes, here’s a fun fact: the protein bars, shakes, and even chocolate oats you enjoy probably contain soya protein. Did they ever cause discomfort or harm? Of course not (unless you are allergic to soya).

Still, doubts about soya keep coming back now and then. Before you cut it out of your diet, here are some soya protein myth vs reality points to clear the confusion.

Myth 1: Soya Protein Affects Hormones in Men and Women

This is one of the most common myths about soya. Because it contains isoflavones, plant compounds that resemble oestrogen, many assume it can disturb hormone balance.

Here’s the truth: it doesn’t.

Isoflavones may act like oestrogen in structure, but they act differently in the body. Research shows that eating moderate amounts of soya protein does not affect testosterone levels in men or oestrogen levels in women.

In fact, a large meta-analysis of 41 clinical studies found that neither soy nor isoflavone intake affects male reproductive hormones (PubMed, 2021). Another study published in The Journal of Nutrition found no hormonal disruptions among women who regularly consumed soy.

So yes, you can safely eat soya foods without worrying about hormonal imbalance.

Also Read: Is Soya Protein Gluten-Free? What You Need to Know

Myth 2: Soya Protein Causes Digestion Problems

This is another common myth that keeps people away from trying soya: it’s heavy on the stomach or causes bloating.

Actually, it doesn’t, at least not for most people. 

A review on Soy and Gastrointestinal Health found that fermented and minimally processed soy foods can actually support gut health by improving gut bacteria and aiding digestion (PMC Study, 2023).

So, unless you are allergic to soya, it’s easy to digest and perfectly safe for regular use.

Myth 3: Soya Protein Leads to Weight Gain

Many assume that adding soya to their diet will make them put on extra weight. But research suggests the opposite.

One study published in The American Journal of Clinical Nutrition found that soy protein helped reduce body fat while maintaining lean muscle mass. Soya has beneficial effects on obesity, favourably affecting satiety and reducing excess body fat. (PMC, 2008)

Thus, soy protein for weight loss is a healthy choice as it is rich in protein and low in saturated fat. 

Myth 4: Soya Protein Affects Thyroid Function

Is soya protein bad, as it disturbs thyroid activity? Nope. Research doesn’t support this for healthy individuals. Studies show that soy isoflavones don’t significantly alter thyroid hormone levels when iodine intake is adequate (PMC, 2019).

For those with hypothyroidism, the only caution is with medication. Soya may slightly reduce the absorption of thyroid tablets if consumed too close to the dose (Mayo Clinic, 2024). Keeping a few hours between your medicine and soya foods is usually enough.

In short, soya protein is safe for most people and does not interfere with normal thyroid function.

Also Read: How to Choose the Right Soya Protein Supplement?

Myth 5: Soya Protein Causes Breast Cancer

For years, people have linked soya protein with breast cancer risk because it contains isoflavones. But studies show these compounds don’t act like human hormones, nor do they increase cancer risk.

Extensive research confirms that soya protein is safe and may even protect against breast cancer. A review report found that soy consumption was linked to a lower risk of breast cancer and improved survival rates among women diagnosed with it (PubMed, 2016). 

The overall evidence is clear: moderate soy intake is safe for women, including those with a history of breast cancer.

Myth 6: Soya Protein Is Inferior in Quality to Animal Protein

It’s often assumed that plant proteins don’t match the quality of animal proteins. But that’s not true for soya. Soya protein is a complete protein, meaning it provides all nine essential amino acids in adequate amounts, just like meat, eggs, or dairy.

Research shows that, when compared under controlled conditions, soya protein produces gains in muscle strength and lean body mass similar to those of animal protein (PubMed).

Myth 7: Soya Protein Worsens Hormonal Imbalance in Women with PCOS

It’s often thought that soya can worsen hormonal issues in women with PCOS. Research says the truth about soya protein. A clinical trial found that soy isoflavones reduced testosterone and improved insulin resistance in women with PCOS after 12 weeks of intake (PMC, 2011).

This means soya protein doesn’t disrupt hormones. It may actually support better metabolic and hormonal balance when consumed moderately.

Takeaway

• Before investing in bulk soy protein, start with a small pack to see how your body responds.

• Choose FSSAI-certified and non-GMO products for safety and quality assurance.

• Don’t fall for myths. Rely only on authentic, research-backed information.

• Opt for soy protein with around 90% pure protein content for maximum nutritional value.

For trusted quality, go with Prowise India, its the best isolated soy protein supplier in Rajasthan.