Soy may reduce risk of cardiovascular disease

Jan 12 2005

Every 34 seconds, an American man or woman dies of cardiovascular disease. Now, research suggests that a diet rich in soybean oil can help. Two new studies shed light on the power of alpha-linolenic acid (ALA) to reduce heart disease risk. Soybean oil provides an excellent source of ALA, as do leafy greens, some nuts and flax.

Scientists now believe that ALA decreases C-reactive protein (CRP), a marker of inflammation strongly associated with heart disease. In one study, Dr. Penny Kris-Etherton of Penn State University studied the effects of three experimental diets: the average American diet, a linoleic acid (LA) diet and an ALA diet. After six weeks, the researchers found that CRP declined after both the LA and ALA diets, but much more significantly in the ALA diet.

The study chose 23 participants who represented the typical individual at risk for cardiovascular disease, selecting 20 men and three women who were overweight, about 50 years old on average, and had moderately elevated total cholesterol and LDL ("bad") cholesterol. The study appears in the November issue of the Journal of Nutrition.

In a second study, Dr. Christine Albert of Harvard Medical School examined the diets of women taking part in the Nurses Health Study. Dr. Albert found a protective association between ALA intake and coronary heart disease among the women she observed in the study. The Nurses Health Study has monitored 76,000 women's lifestyles and health over a sixteen year time period. Dr. Albert presented the research at a recent meeting of the American Heart Association.

Jackie Newgent, a New York City-based registered dietitian, recommends that consumers keep an eye on their cooking oil's label. Newgent commented, "Food companies frequently label soybean oil as vegetable oil on the front of their bottles. For a great source of ALA, just check the back of the vegetable oil bottle and you'll usually see soybean oil listed as the only ingredient." Newgent also noted that incorporating ALA into the diet should be part of an overall eating plan that also limits saturated fat, trans fat and cholesterol, while balancing calories in with calories out. "It's always important to think teaspoons, not tablespoons, when using cooking oil," cautioned Newgent.

Soy protein's heart health benefits have won widespread recognition since the Food and Drug Administration (FDA) approved a health claim in 1999. The health claim states that 25 grams of soy per day may help reduce risk of heart disease. The new research on ALA offers important new information that the oil produced from soybeans may also play an important role in heart health. Soybean oil represents approximately 80 percent of edible oil consumed in the United States.

According to 2004 statistics from the American Heart Association (AHA), heart disease continues its firm grasp as the nation's number one killer of both men and women. Heart disease claims more lives than the next five causes of death combined, which are cancer, chronic lower respiratory diseases, accidents, diabetes mellitus, and influenza and pneumonia.