Humans have been eating soybeans for thousands of years. This plant is native to Asia, but now grows all over the world as a hearty staple. Soybeans are processed for supplements, food and food additives. Although soy is touted as having many cardiovascular benefits, the underlying research on soy and heart health is conflicting.
Pro-Soy Research
In 1999, after a thorough review of evidence, the Food and Drug Administration ruled that food labels could claim an association between soy protein and a reduced risk of coronary heart disease. This lower risk is attributed to soy protein and its effect on lowering blood cholesterol levels. The University of Maryland Medical Center explains that soy protein may reduce levels of low-density lipoprotein, or LDL, also called "bad" cholesterol. Too much LDL can cause your arteries to narrow or become blocked, leading to heart disease or a heart attack. While not all studies agree on soy's effect on heart disease, most evidence links soy consumption to a 10 percent reduction in LDL cholesterol and a 7 percent reduction in total cholesterol.
Anti-Soy Research
Some research has found that soy may not be beneficial for heart disease risk reduction after all. Research conducted in 2006 at Tufts University for the Nutrition Committee of the American Heart Association and published in the journal "Circulation" could not link soy protein with favorable effects on heart health. Those who eat large amounts of tofu -- more than half their daily protein intake total -- may lower cholesterol a few points, the researchers pointed out, but this is not a typical consumption level for Americans.
Recommended Amounts of Soy
Since there are conflicting views about the effects of soy on heart health, perhaps the best choice is to eat soy for its dietary value and as a replacement for high-fat foods. The American Heart Association suggests that adults consume 25 g of soy protein a day.
Soy Products
Some food sources for soy include soy protein isolate, which is added to products such as soy patties; soy flour; whole soybeans; tempeh; tofu; and edamame. Many products will list the amount of soy protein on the Nutrition Facts label; you can also read the list of ingredients to see if the product contains isolated soy protein. Soy milk has also become popular product in recent years. You can find a variety of soy milk brands in plain, vanilla and chocolate-flavored varieties.
References
- The New York Times Health Guide; Soy; March 26, 2007
- Tufts University; Research into soy will continue but soy is not a solution for heart disease; Gallagher, Siobhan; February 6, 2006
- American Cancer Society: Soybean
- "Federal Register"; Food labeling: health claims; soy protein and coronary heart disease: Food and Drug Administration, HHS: Final rule; October 1999
- UMMC: Soy
- "Circulation"; Soy protein, isoflavones, and cardiovascular health; F.M. Sacks, et al.; Feb 2006
