{"id":22355,"date":"2026-05-26T09:32:59","date_gmt":"2026-05-26T16:32:59","guid":{"rendered":"https:\/\/foodrevolution.org\/?p=22355"},"modified":"2026-05-26T09:33:03","modified_gmt":"2026-05-26T16:33:03","slug":"soy-facts-is-soy-healthy","status":"publish","type":"post","link":"https:\/\/foodrevolution.org\/blog\/soy-facts-is-soy-healthy\/","title":{"rendered":"Soy Facts: Is Soy Healthy or Harmful?"},"content":{"rendered":"

Starting in the mid-1930s, the Ford Motor Company used a <\/span>bushel of soybeans<\/span><\/a> in every car it made. No, they weren\u2019t using soy sauce as wiper fluid. Henry Ford had challenged his engineers to figure out how to turn soy into plastic. At first, they used this soy-based plastic for gas pedals, window frames, horn buttons, and the knobs at the ends of gear-shifter rods \u2014 among other things. But in 1941, Ford unveiled the \u201c<\/span>Soybean Car,<\/span><\/a>\u201d which replaced much of the steel with soy plastic. It was half a ton lighter than the all-steel car it resembled, and it was safer. Sadly, it didn\u2019t enter production, so we were never blessed with car names like the Ford Tofu or the Mercury Miso.<\/span><\/p>\n

I tell you this partly because I think it’s a great story, and partly because it captures something essential about soybeans: They’re not quite like anything else in the plant kingdom. While they’re members of the legume family, their unique biochemistry has made them useful in ways that most foods never are \u2014 as food, as industrial material, as soil replenisher, and as one of the most hotly debated ingredients in modern nutrition.<\/span><\/p>\n

That last part is what we’re here to talk about. Because for all the enthusiasm around soy, and there’s a lot of it, in both directions, the actual science is more interesting and more nuanced than the loudest voices on either side would suggest.<\/span><\/p>\n

Should You Eat Soy?<\/span><\/h2>\n

Soy does get eaten by people \u2014 especially in many Asian cultures, where it\u2019s been a significant source of nutrition for centuries. In fact, the Chinese word for soybean is \u201c<\/span>tatou<\/span><\/a>,\u201d which means \u201cthe greater bean.\u201d\u00a0<\/span><\/p>\n

Legumes like soy make up a substantial portion of the diets in the <\/b>Blue Zones<\/b><\/a> \u2014 the areas around the world known for longevity, with many people living to 100 years or older.\u00a0<\/b><\/p>\n

Traditional Okinawans, who live in the Blue Zone of Okinawa, Japan, eat a lot of soy, mainly in the form of tofu and miso. They have among the world\u2019s highest life expectancies. And those tend to be healthy life-spans. Soy-eating Okinawan elders are among the <\/span>healthiest people in the world<\/span><\/a>. <\/span>Compared to North Americans<\/span>, they have a staggering 80% less breast cancer and prostate cancer, and less than half the ovarian cancer and colon cancer.\u00a0<\/span><\/p>\n

Studies have also found that regular consumption of whole soy foods is associated with lower rates of many other forms of cancer, as well as <\/span>heart disease<\/span><\/a> and <\/span>type 2 diabetes<\/span><\/a>.\u00a0<\/span><\/p>\n

Despite all this positivity, soy is not without its detractors. Some wellness influencers <\/span>blame soy<\/span><\/a> for promoting breast cancer, and even growing \u201cman boobs.\u201d They also point out that most soy substitutes for cheese and meat are highly processed.\u00a0<\/span><\/p>\n

There are also valid environmental concerns. Some soy farming contributes to <\/span>rainforest destruction<\/span><\/a>. And most soybeans grown today are genetically engineered to be herbicide-tolerant, and then sprayed with glyphosate and other problematic pesticides.<\/span><\/p>\n

So where does that leave us? Should you avoid organic tempeh? What\u2019s good about soy, and what considerations are necessary when adding it to your diet? And what are some of the best ways to consume soy? Let\u2019s get the facts.<\/span><\/p>\n

What is Soy?<\/strong><\/h2>\n
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iStock.com\/Zoya2222<\/figcaption><\/figure>\n

Soybeans, also called soya beans in the United Kingdom, are legumes that are <\/span>native to East Asia.<\/span><\/a> The official name of the soy plant is <\/span>Glycine max<\/span><\/i><\/a> (which sounds like the name of a streaming platform: \u201cAll soy, all the time.\u201d) Most dried soybeans are light tan or pale yellow, while some varieties are black, brown, and even blue.<\/span><\/p>\n

Fresh soybeans, called edamame in Japanese, are always green. They\u2019re often sold in their pods: raw, frozen, or pre-cooked.<\/span><\/p>\n

Where Is Soy Grown & How Is It Used?<\/span><\/h2>\n

Soy has spread out from its East Asian origins and is <\/span>now grown<\/span><\/a> abundantly in Brazil, Argentina, India, Paraguay, Canada, and the United States. From humble beginnings \u2014 a few seeds grown by a colonist in Georgia in 1765 \u2014 soy has colonized much of American cropland, to the point where the U.S. is now the world leader in soy production. In fact, in the U.S., approximately <\/span>119 million metric tons<\/span><\/a> of soybeans are grown on <\/span>86 million<\/span><\/a> acres of land each year. That\u2019s more than 100 times the size of the entire state of Rhode Island, which at this point has probably come to accept its role as America’s official unit of measurement for things that dwarf it.<\/span><\/p>\n

For comparison, wheat covers about 50 million acres, while corn tops the charts with 90 million acres. But unlike those crops, soy can actually restore soil fertility when grown responsibly.\u00a0<\/span><\/p>\n

George Washington Carver, the brilliant agricultural scientist whose research transformed Southern farming in the early 20th century, found that rotating soybeans into planting cycles actually increased cotton yields, thanks to the legume’s ability to transfer nitrogen from the air into the soil.<\/span><\/p>\n

You can see that soy could be a kind of wonder crop, feeding people, replacing petroleum in manufacturing, and replenishing agricultural soil. Unfortunately, we\u2019re using most of our soy crop in wasteful and environmentally harmful ways. <\/span>More than 75% of the enormous amount of soy grown worldwide is <\/b>fed to livestock<\/b><\/a>.<\/b> In the U.S.<\/span><\/a>, that number rises to more than 90%.\u00a0<\/span><\/p>\n

And the vast majority of the soy consumed by humans in the U.S., South America, and Europe is highly processed into soy oil and soy protein isolate, along with other ingredients that often end up in ultra-processed foods. By contrast, in Asian countries, whole soybeans and fermented soy products<\/span> like edamame, tempeh, soy sauce, and natto are common fare, and have been for centuries.\u00a0<\/span><\/p>\n

Soy Nutrition<\/span><\/h2>\n
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iStock.com\/Kritchai Chaibangyang<\/figcaption><\/figure>\n

The soybean is significantly higher in fat, lower in carbohydrates, and slightly higher in protein than other legumes. It tends to be <\/span>more digestible<\/span><\/a> than other plant proteins and contains all nine essential amino acids. (In this case, \u201cessential\u201d simply refers to the ones that our bodies cannot metabolize, and so we must source them from food.)\u00a0<\/span><\/p>\n

The carbohydrates in soybeans are primarily oligosaccharides, which <\/span>promote healthy gut microbiota<\/span><\/a> like <\/span>Bifidobacteria <\/span><\/i>by acting as a prebiotic in your intestinal tract. The fat content of the soybean consists of 19% to 41% monounsaturated fats, 46% to 62% polyunsaturated fats (including a modest amount of omega-3 fatty acids), and 10% to 15% saturated fats. Soy is also packed with a wide array of vitamins and minerals.\u00a0<\/span><\/p>\n

One-half cup of roasted mature soybeans has the following <\/span>nutritional composition<\/span><\/a>:<\/span><\/p>\n