What is soy protein isolate, found in vegan foods, and is it bad?
You see this ingredient in so many vegan products, but what is it? And should you be worried about eating it? Here’s the inside scoop on soy protein isolate and why it’s found in so many vegan or plant-based foods.
The Impossible Burger has it. Likewise, make vegan protein bars, other fake meats, and granolas. In fact, suffice it to say that if you’re eating vegan food, you’re probably consuming soy protein isolate. Yet, although you know about soy and protein and know that they are healthy, the isolate part confuses you. No more, as the experts weigh in below and explain what this foreign-sounding ingredient is – and why it shouldn’t be a huge concern.
Define soy protein isolate?
True to its name, soy protein isolate comes from soybeans, specifically defatted and shelled soybeans, according to the Nutrition review. By soaking soybeans, protein can essentially be isolated and dehydrated. As a result, this soy protein isolate becomes an ultra-rich source of protein, its protein content about 90%, says Nanci S. Guest, Ph.D., RD, CSCS, plant-based dietitian and scientist in nutrition from the University of Toronto in Ontario.
Soy protein isolate is then added to foods, which not only increases protein content, but also does so without adding extra fat or calories. It’s not unlike how manufacturers use whey protein isolate with one obvious difference. “Soy protein isolate comes from plants, and whey is one of two dairy proteins,” says Guest.
The benefits and harms of soy protein isolate
Over the years, soy has had to fight to earn its rightful place in the health food world, with people often harboring the mistaken belief that isoflavones, also known as phytoestrogens, in soy can increase your risk of cancer. breast or prostate (or other hormones) . Fortunately, many studies now exist to show the benefits of eating a moderate amount of whole soy foods like soybeans and edamame, and even minimally processed soy foods like tofu and soy milk. . “These foods help reduce the risk of cancer, especially breast and hormone-related cancers, and cancer recurrence,” says Susan Levin, MS, RD, CSSD, director of nutrition education for the Physicians Committee for Responsible Medicine.
So what’s the deal with soy protein isolate? There are concerns that, like cow’s milk, soy protein isolate may increase insulin-like growth factors such as IGF-1. “Once soy protein isolate is extracted from food, it can promote cancer and cancer growth,” says Levin, citing a study in Nutrition and Cancer which recommended that men with early-stage prostate cancer “not exceed dietary protein recommendations.”
Others, however, say the opposite. “There is no evidence that soy protein isolate works any differently than soy food,” Guest says. In fact, soy protein isolate may have health benefits.
Soy protein isolate may be beneficial in small amounts
According to the National Cancer Institute (NCI), soy protein isolate has been shown “to reduce the incidence and growth of tumors in some animal studies and may also ‘inhibit endothelial cell proliferation.’ it contains phytoestrogens, which cause mild estrogen-like effects, soy protein isolate may help regulate hormonal balance and reduce the risk of breast cancer, heart disease and osteoporosis Levin notes, however, that the NCI cites studies done on animals, not humans, that could affect the results.
And for people who want to improve their fitness in the gym, soy protein isolate could also be beneficial: “Soy protein isolate is firmly established as a high-quality protein that promotes muscle mass gains and strength in people engaged in endurance physical training,” says Mark Messina, Ph, D., MS, president of Nutrition Matters in Pittsfield, Mass. Soy protein isolate also lowers cholesterol slightly.
Should you eat soy protein isolate if you want more protein in your diet?
Whether you eat soy protein isolate depends on what you hope to get out of it. If you want to receive all of the same health benefits as whole soy foods, you may be out of luck. “Soy protein isolate is lower in isoflavones and doesn’t provide some of the other components found in whole soybeans like fiber and omega-3 fatty acids,” Messina says, though he says foods with soy base and isolate may play a role in the diet.
On the other hand, however, soy protein isolate can help you meet your protein needs. The question, of course, is whether you need that much protein in a single serving. “A small food with 20 grams of protein is a ridiculously high amount,” Levin says, adding that it may be more of a marketing ploy at this point. “Companies play on your fear that you need more protein.”
Ultimately, soy protein isolate isn’t the biggest red flag in the health world, and if you eat it occasionally or in moderation, it shouldn’t be a problem, says Wine. Still, for optimal benefits, strive to eat whole sources of soy whenever possible.