Is soy healthy?

This is a common question, especially among those who go vegetarian, vegan, or plant based. Many people have concerns regarding hormones, GMO soy, etc. There is a lot of misinformation regarding soy out there. It's important to always consider the source when determining whether or not soy is healthy and if you should make it a part of your diet. If you ask "Is soy healthy?" there is no shortage of people who are ready to give their opinions, but their opinions may not be based on fact or scientific research. 

Avoid the scare tactics put out by some people and companies, which only serve to make people skeptical about soy. The vast majority of soy that is GMO in the country is fed to livestock. That doesn't mean that there is no GMO soy for human consumption, because there certainly is. But that counters the argument that some people have that soy is all GMO. The store is filled with soy products that clearly state they are non-gmo. Seek out those products and stick to them. This goes for products beyond soy, because you want to avoid GMO products as much as possible, not just when it comes to soy.

Some people have concerns regarding soy in processed foods. That's a legitimate health concern, but not because of the soy. All processed foods are suspected to be unhealthy, not just the ones that contain soy. It's always best to stick with whole foods, so when it comes to soy you should stick with tofu, tempeh, soy milk, edamame, and eat less of things like veggie burgers and veggie dogs, which are processed items that contain soy. It's not the soy itself that makes those things less healthy, it's the fact that it's a processed food. Soy contains all amino acids your body needs, and is a good source of protein, fiber, potassium, magnesium, iron, and copper.

Here are some credible sources and what they say regarding whether or not soy is healthy to consume:

• Nature.com - This article shares research findings about soy consumption in China, including how much they consume, and the health benefits. It also addresses the concerns that some people have about consuming it.
• Harvard School of Public Health - "Soy is a nutrient-dense source of protein that can safely be consumed several times a week, and is likely to provide health benefits—especially when eaten as an alternative to red and processed meat."
• NutritionFacts.org - The information on this research-based website suggests that soy is healthy. Specifically, they report that soy lowers breast cancer risks, and that women who have had breast cancer experienced less recurrence and  live significantly longer if they consumed tofu. Further, they report that it's healthy for the kidneys. Additionally, they offer information on how phytoestrogens can have anti-estrogenic effects.
• American Cancer Society - They report that the health benefits of eating soy outweigh any potential risks.  They also report that there is growing evidence that consuming soy products such as tofu, tempeh, miso, and edamame, lower breast cancer risks, and it has been linked to lower rates of heart disease.
• Cleveland Clinic - Offers information on the many benefits of whole soy foods.
• Mayo Clinic - Soy reduces the risk of breast cancer.

Specific research studies regarding soy and health:

• May 2023 issue of the journal Nutrients, reports that menopausal women are more prone to non-alcohol fatty liver disease, and they conclude that "Consumption of soy foods may provide hepatic benefit to postmenopausal women..."
• April 2022 there is published research in the journal In Vivo, which finds that soy isoflavones help to reduce risks of getting breast cancer.
• January 2020 issue the American Journal of Clinical Nutrition - Researchers report that it is increasing certain soy products can help people prevent Type II diabetes.
• November 2019 issue of the journal European Journal of Epidemiology - Researchers conducted a study on 300,000 women in China and conclude that daily soy intake reduces breast cancer risks.
• December 2016 issue of the journal Nutrients -  Researchers report that soy protein is higher quality than other legume proteins, lowers cholesterol levels, lowers blood pressure, leads to a favorable change in the fatty acid content in the diet, alleviates hot flashes, and improves arterial health in menopausal women. They also report that "population and clinical studies involving adults suggest benefits are associated with approximately two to four servings per day."
• June 2019 issue of the journal Complementary Therapies in Medicine - Researchers report that soymilk consumption was beneficial for those with non-alcoholic fatty liver disease.
• 2019 issue of Asia Pacific Journal of Clinical Nutrition - Scientists report that consuming soy daily may decrease the risk of type 2 diabetes.
• May 2019 issue of journal Frontiers in Endocrinology - Researchers reported that soy improved insulin resistance and LDL.
• 2019 issue of the journal NeuroRehabilitation - Researchers report that soymilk consumption helps improve walking speed, exercise endurance, grip strength, and muscle functionality in chronic stroke patients.
• March 2019 issue of the journal Scientific Reports - Researchers report that soy supplementation has no effect on thyroid hormones.
• 2019 issue of the journal Acta Odontologica - Scientists report that soy beverages have a lower tooth enamel erosion risk than non-soy beverages.
• January 2019 issue of the journal Food Chemistry - Researchers report that "fermented soy products also proved to be effective in attenuating the effects of diabetes mellitus, blood pressure, cardiac disorders and cancer-related issues."
• July 2019 issue of the Journal of Cardiovascular Pharmacology - Researchers report that soy inhibits endothelial cell dysfunction and helps to prevent cardiovascular disease. 
• August 2019 issue of Hypertension Research - Researchers report that long term intake of miso soup helps to reduce nighttime blood pressure.
• September 2019 issue of the journal Nutrition Reviews reports that soy isoflavones may improve cognitive function in adults.
• October 2019 issue of the journal Molecular Nutrition & Food Research, the study reports that soy and isoflavone consumption seems more beneficial than harmful for a series of health outcomes. Beneficial associations were identified for cancers, cardiovascular disease, gynecological, metabolic, musculoskeletal, endocrine, neurological and renal outcomes, most especially in perimenopausal women. 
• In a 2016 issue of the journal Complementary Medicine Research, they state that soy consumption in regard to breast cancer: prospective epidemiologic studies involving over 11,000 women from the USA and China show that postdiagnosis soy intake statistically significantly reduces recurrence and improves survival.
• NutritionFacts.org explains the benefits of soy in helping to prevent breast cancer and reduce recurrence of it.
• Polyphenols are important to being healthy and avoiding some illnesses and diseases. Soy ranks in the top 100 items you can eat in terms of being one of the richest sources of polyphenols. All types of soy make the top 100 list, including soybeans, soy flour, tofu, tempeh, soy cheese, soy yogurt, and soy meats. You can check out the top 100 list here.
• Watch this video, starting at the 18:30 minute mark if you only want the info about soy and breast cancer. The doctor explains the research on soy and how it helps reduce death risks in those with breast cancer (as well as it recurring).

Health professionals recommend eating it in moderation, which is defined as 1-2 servings per day. A serving is roughly 1 cup of soy milk, 1/2 cup cooked soybeans, 1/2 cup of edamame, 1 ounce of soy nuts, or 1/3 cup of tofu. Soy has been consumed by Asian cultures for thousands of years. The people who live the longest in the world, and tend to be the healthiest, are the Okinawans, in Japan. Their diet is largely plant-based (it's estimated that only 2% of their diet is meat/fish/poultry), with the bulk of their diet being sweet potatoes. Plus, they eat soy, such as tofu and miso, every day.

The bottom line is that there is plenty of scientific research backing the idea that soy is healthy for  those who do not have an allergy to it. Soy is a healthy food that appears to have numerous health and protective properties. Making tofu, soymilk, miso, and tempeh a part of your diet is a good idea!