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Soy and Your Health

Soy is a widely consumed food around the world, especially in Asian countries where it has been a dietary staple for thousands of years. However, in recent years, there has been a lot of debate about the health benefits and concerns associated with soy consumption. Let's explore the benefits and potential drawbacks of soy consumption and help you decide whether soy is a healthy choice for you.

What is Soy?

Soy is a type of legume that is rich in protein, fiber, and essential nutrients. It is a common ingredient in many processed foods, such as tofu, soy milk, tempeh, and miso.

Soy products are also used as meat alternatives, as they provide a good source of plant-based protein.

Benefits of Soy

Soy is an excellent source of plant-based protein. It contains all the essential amino acids that our body needs to build and repair tissues, making it a valuable addition to the diet of vegetarians and vegans.

Soy is also rich in fiber, which can help promote bowel regularity and reduce the risk of chronic diseases such as heart disease, diabetes, and cancer.

Heart Health

Soy has been shown to have several benefits for heart health. For example, studies have found that soy consumption may help reduce blood pressure, a major risk factor for heart disease. This is thought to be due to the presence of peptides in soy protein that can help relax blood vessels and improve blood flow.

Additionally, soy products are rich in antioxidants, which can help protect the body against oxidative stress and inflammation, which is a key factor in the development of heart disease.

Inflammation can damage blood vessels and lead to the buildup of plaque, which can narrow the arteries and increase the risk of heart attack and stroke.

Another benefit of soy consumption is its potential to lower cholesterol levels. Studies have shown that soy protein can reduce LDL cholesterol levels, which is known as "bad" cholesterol, and increase HDL cholesterol levels, which is known as "good" cholesterol.


A review of the research literature conducted by the American Diabetes Association found that soy intake was associated with improvements in blood sugar control and insulin sensitivity.

This risk reduction may be due to the fiber, protein, or phytonutrient content, but is most likely due to a combination of all three.

Concerns about Soy

Despite the many benefits of soy consumption, there are also some concerns about its safety and potential health risks. Are they valid?

Breast Cancer

Soy contains phytoestrogens, which are compounds that have a similar structure to estrogen and were previously thought to have estrogenic effects in the body.

Updated research has not supported this theory, and in fact now believe phytoestrogens may play a protective role.

A review of the research literature conducted by the American Cancer Society concluded that soy foods are safe and may even be beneficial for breast cancer survivors. The review found that consuming soy foods did not increase the risk of breast cancer recurrence or mortality among breast cancer survivors.

Similarly, a meta-analysis of 35 epidemiological studies conducted in 2016 found that soy intake was not associated with an increased risk of breast cancer, and may even have a protective effect. The analysis found that higher soy intake was associated with a 14% reduction in breast cancer risk.

Thyroid Health

Several studies have examined the relationship between soy intake and thyroid function. A review of the research literature conducted by the American Thyroid Association concluded that soy foods, consumed in moderation, do not appear to adversely affect thyroid function in healthy individuals.

It is important to note that most of the studies examining the relationship between soy and thyroid function have been conducted in healthy adults. More research is needed to understand how soy intake may impact thyroid function in people with pre-existing thyroid conditions.


While there is no clear evidence that GMO soy is harmful to human health, some people may prefer to avoid it due to concerns about the potential long-term effects of GMOs. Those concerned about GMOs may want to choose organic or non-GMO soy products.

Allergy / Sensitivity

Soy is a common allergen and can cause side effects among some people, such as indigestion, rashes, hives and in serious cases, anaphylaxis. People with a soy allergy or sensitivity should avoid soy products altogether.


Overall, soy is a healthy food choice for most people. It is an excellent source of protein and fiber and has been shown to have numerous health benefits, including reducing cholesterol levels and protecting against chronic diseases.

While there are some concerns about soy, the evidence suggests that consuming it in moderation has more benefits than potential risks for healthy individuals, unless an allergy or sensitivity is present.




  1. American Cancer Society. (2021). Soy and Breast Cancer Risk. Retrieved from

  2. American Thyroid Association. (2018). Soy and the Thyroid. Retrieved from

  3. Anderson, J. W., Bush, H. M., & Zhang, X. (2011). Soy protein effects on serum lipoproteins: A quality assessment and meta-analysis of randomized, controlled studies. The Journal of the American College of Nutrition, 30(2), 79–91.

  4. Chi, F., Wu, R., Zeng, Y. C., Xing, R., Liu, Y., Xu, Z. G., & Fan, X. M. (2016). Soy consumption and risk of breast cancer: a meta-analysis of observational studies. Cancer Epidemiology, Biomarkers & Prevention, 25(8), 1175-1184.

  5. Ferdowsian, H. R., & Barnard, N. D. (2009). Effects of plant-based diets on plasma lipids. The American Journal of Cardiology, 104(7), 947–956.

  6. Messina, M., & Redmond, G. (2006). Effects of soy protein and soybean isoflavones on thyroid function in healthy adults and hypothyroid patients: A review of the relevant literature. Thyroid, 16(3), 249–258.

  7. Messina, M., & Messina, V. (2010). The role of soy in vegetarian diets. Nutrients, 2(8), 855–888.

  8. Reynolds, K., Chin, A., Lees, K. A., Nguyen, A., Bujnowski, D., He, J., & Shi, X. (2016). A meta-analysis of the effect of soy protein supplementation on serum lipids. The American Journal of Cardiology, 98(5), 633–640.

  9. Wang, Y., Jones, P. J., Ausman, L. M., & Lichtenstein, A. H. (2005). Soy protein reduces triglyceride levels and triglyceride fatty acid fractional synthesis rate in hypercholesterolemic subjects. Atherosclerosis, 181(1), 87–93.

  10. Wilcox, G., Wahlqvist, M., Burger, H. G., Medley, G., & Stuart, L. (1982). Oestrogenic effects of plant foods in postmenopausal women. British Medical Journal, 284(6318), 1267–1269.

  11. Zhang, X., Shu, X. O., Li, H., Yang, G., Li, Q., Gao, Y. T., & Zheng, W. (2003). Prospective cohort study of soy food consumption and risk of bone fracture among postmenopausal women. Archives of Internal Medicine, 163(15), 1897–1904.

Is soy healthy? Exploring the benefits and concerns

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