Americans have fallen in love with the soybean. Seems that soy is in practically everything these days!
Soy foods like soy milk, soy ice cream, soy nuts, soy yogurt, soy burgers, and soy cheese are flooding supermarket shelves. And sales of soybean products in the U.S. have more than tripled in the past decade to around $3 billion a year. That’s a whole lot of soy.
There are many research studies that show that people who eat diets high in soy, as well as high in vegetables, have less risk for certain types of cancer.
In recent years the humble soybean, and its many incarnations (see ‘Soy What?’), has been touted as a cure-all miracle worker. Convinced it can prevent everything from heart attacks to hot flashes to cancer, consumers have sent soy sales soaring. But how much of the soy hype is based on fact and how much is fiction?
Soybeans belong to the family of legumes, the same as peas and lentils. Soybeans are high in protein and fiber and rich in vitamins and minerals, and they’re also loaded with phytochemicals.
Phytochemicals are non-nutritive substances found in plants that are believed to offer various health benefits. Soy is naturally rich in isoflavones (a type of phytochemical), which are thought to play a critical role in the positive health aspects associated with consuming soy, such as relieving menopausal symptoms and protecting against cancer, heart disease, and osteoporosis.
It all started in Asia. For centuries soybeans have been mainstays of diets throughout Japan and China. Asians have lower incidences of breast and prostate cancers and heart disease than Americans. They also have fewer hip fractures, and Asian women report fewer symptoms from menopause.
“There are many research studies that show that people who eat diets high in soy, as well and high in vegetables, have less risk for certain types of cancer. And there is currently a FDA (Food and Drug Administration) petition pending that will allow this type of health claim on foods containing soy”, says Barbara Klein, Co-Director for the Illinois Center for Soy Foods.
Although the optimal isoflavone intake to prevent or treat specific diseases is not known, it is apparent that including soy protein in one’s diet can help lower cholesterol levels. “It’s generally accepted that soy consumption lowers serum cholesterol levels”, says soy expert Stephen Barnes of the University of Alabama, Birmingham.
The FDA officially recognized the cholesterol-lowering effects of soy in 1999, when they told manufacturers that their labels could claim that soy can help reduce the risk of heart disease. The FDA-approved health claim states that 25 grams of soy protein per day may reduce the risk of heart disease. The FDA, however, allows soy foods that contain a quarter of that amount (6.25 grams) per serving, to carry the claim.
And your heart is not the only reason to start noshing soy. Soy protein products are excellent substitutes for animal products because soybeans are the only common plant foods that contain ‘complete’ protein, meaning they provide all the essential amino acids needed for human health. In fact, the amino acid profile of soy protein is nearly equivalent in quality to meat, milk, and egg protein. This means that soy products can replace animal-based foods that tend to contain more saturated fat and cholesterol. So the next time you are deciding between a hamburger and a soy-burger, go with the latter.
More good soy news: people who have trouble digesting lactose (the naturally occurring sugar in milk), and people who are allergic to milk protein, should have no trouble with soy dairy. And growing soy takes less of a toll on the environment than raising dairy cows as it takes nearly ten times more energy to produce and transport livestock than vegetables.
While soy foods clearly get the healthy green light, soy supplements are another matter. Concentrated soy isoflavones are now available in supplement form, but it remains unclear whether they can provide the same health benefits as soy isoflavones consumed as part of the diet. Mark Messina, author of The Simple Soybean and Your Health (Avery Publishing Group, 1994), advises against taking isoflavone supplement pills and capsules, as no scientific research has been done to prove that they are effective or safe.
Another concern is the variable amounts of isoflavones found in soy supplements, and how these differ from the levels in soy foods. Because you don’t know what you’re getting in these supplements, or even what would be a good formulation, it’s best to stick with soy foods.
The Bottom Line:
The soybean is not a cure-all, but soy foods are worth adding to your diet since they help reduce the risk of heart disease and may have other health benefits. They are an environmentally-friendly, healthy substitute for meat, poultry, and other animal-based products and a delicious addition to a balanced, varied diet low in saturated fat and cholesterol.