With more people turning to plant-based diets for health reasons, soy foods continue to be a healthy choice for meeting nutritional needs.
“Soy products can be a part of a healthy eating pattern when eaten as an alternative to red meat or processed meats that are high on cholesterol and saturated fats and can increase your risk of heart disease,” says Arta Shirkhodai, MD, an internal medicine physician at Scripps Coastal Medical Center Vista.
Soybeans are low in saturated fats compared to animal sources of protein. As a plant-based source of protein, soy foods can be part of a healthy vegetarian diet, according to the 2020-2025 Dietary Guidelines for Americans.
People most likely to benefit the most from a soy-rich diet are those with high cholesterol, obesity, type 2 diabetes and other risk factors for heart disease.
Soy foods are made from soybeans, a legume that has been around for thousands of years. Soybeans are rich in protein, fiber vitamins and minerals and are cholesterol free. Soybeans are also high on soy isoflavones, which are associated with a variety of health benefits.
Studies suggest that soy can protect against heart disease, lower the risk of breast cancer, prostate cancer, diabetes and osteoporosis as well as reduce menopause symptoms. More studies need to be done to draw firm conclusions for certain benefits, according to experts.
The American Cancer Society says there is evidence that eating soy foods can lower the risk of breast or prostate cancer but that it is limited.
The American Heart Association recommends eating foods that are high in unsaturated fats — including tofu and other forms of soybeans — instead of foods that are high in saturated fats or trans fats, which can raise cholesterol levels and increase the risk of heart disease.
The Food and Drug Administration has allowed soy products to carry claims that soy protein can reduce the risk of heart disease since 1999. But in 2017, it proposed revoking this authorization, citing mixed results in more recent studies of the heart health benefits of soy.
Soy won’t hurt your heart, but its overall benefits are still being debated.
Concerns have also been raised about the relationship between soy and other health issues. Current evidence does not support that soy consumption is harmful to people. The exception may be people who are allergic to soy.
When it comes to nutrition, there are significant differences between whole soy and the processed soy found in many foods in the United States.
“Whole soy can be a fine addition to diets,” says Dr. Shirkhodai. “It can be a valuable alternative to animal proteins, but soy derivatives are highly processed and can be over consumed.”
Whole soy is complete protein with all nine essential amino acids. It is also a source of fiber, vitamins and minerals. Soybeans are also rich in isoflavones, which are believed to offer a variety of health benefits.
Whole soy food options use the entire bean in its natural state. These include edamame (large soybeans harvested when the beans are still green), soybeans, tofu and soy milk. Soy milk also comes in processed form.
Processed soy is soy that has been dehulled and defatted — and lacks the nutritional value of whole soy. Processed soy products may include unhealthy additives, such as sodium.
Processed soy also comes in the form of soy protein powder or soy protein isolate. These can be found in energy bars, meatless burgers and sweetened soy milks.
“Just because something is vegetarian doesn’t mean it’s necessarily nutritious. Soy-based imitation-meat products often contain overly processed soy,” says Dr. Shirkhodai.
Fermented whole soy products are minimally processed and are considered healthy.
Fermentation neutralizes some of the compounds found in soybeans that can cause difficulty with digestion and creates some beneficial compounds.
Fermented whole soy products are easy to find at your local grocery store, including these foods:
Tempeh is a type of fermented soybean found in solid, cake like sheets that can be cut to size. It can be used with vegetables in a stir-fry or baked and grilled for a sandwich. Crumble it up and add to soups, salads, pasta sauce and casseroles.
Miso is a thick, fermented paste made from soybeans. Brownish in color, it tastes salty and tangy. Its most common use is in soup, but it can also add flavor to sauces and marinades.
Natto is a sticky paste made by adding healthy bacteria to lightly cooked soybeans and fermenting. It is a good addition to soups and broths, as well as a topping for rice dishes. Natto can be an acquired taste due to its strong smell and distinct taste.
Fermented tofu is made from cooked soybeans formed into a custard-like cake, and then fermented to make a white, creamy food resembling semi-soft cheese.