Moderate Amounts of Soyfoods Reduce Cholesterol Levels; Promote Heart Health

As the nation observes National Cholesterol Education Month, new research underscores cholesterol lowering and other health benefits of eating soyfoods.

16/09/08 For the estimated one in two adult Americans with elevated cholesterol levels, there is good news: eating soy burgers, tofu, and other soyfoods is a tasty way to lower both the total amount of cholesterol in the bloodstream and the so-called "bad" low-density lipoprotein (LDL) cholesterol that leads to heart attack and stroke.

The latest evidence, promoted during National Cholesterol Education Month, comes from a review of 35 high quality studies published over a ten-year period (1998-2008) where soy protein was consumed by healthy adults aged 25 to 65 years. Conducted by Arline McDonald, Ph.D., adjunct assistant professor in the Department of Preventive Medicine at Northwestern University's Feinberg School of Medicine, this exhaustive review finds even moderate consumption of soy products in the range of 20 to 50 grams of soy protein daily -- reduced LDL cholesterol levels by 4 percent to 6 percent and total cholesterol by 3 percent to 5 percent beyond what can be achieved through a fat-modified diet alone. These reductions were observed in premenopausal and postmenopausal women, in young adults (25 -30 years), middle-aged adults (30 to 60 years), and adults aged 60 and older. From a public health perspective, a 3 percent reduction in LDL cholesterol reduces mortality by 6 percent.

"These new findings provide encouragement to all Americans who want to reduce their risk for heart disease and stroke," said Dr. McDonald. "Accumulating evidence suggests that in addition to losing weight and eating foods lower in saturated fat and cholesterol, Americans can lower dangerous cholesterol in their systems by eating soyfoods." Soyfoods have also been shown to increase the "good" high-density lipoprotein (HDL) cholesterol, improve blood vessel elasticity, and lower triglycerides, which are all linked with improved heart health.

This new study also reinforces the science behind the health claim approved by the U.S. Food and Drug Administration (FDA) stating "25 grams of soy protein a day, as part of a diet low in saturated fat and cholesterol, may reduce the risk of heart disease." Soyfoods that carry this claim must have at least 6.25 grams of soy protein per serving, which is why health experts recommend getting four servings of soyfoods a day.

Besides being heart-healthy, accumulating research links soyfoods with a number of important health benefits, including improved brain function. According to Carey Gleason, Ph.D., a senior scientist at the University of Wisconsin's School of Medicine and Public Health, studies suggests that soyfoods boost mental ability while large population studies have found a lower incidence of dementia in people living in East Asian countries, where soyfoods are a staple.

At the same time, there is growing evidence that regular consumption of soy protein-containing foods and beverages may reduce the risk of prostate cancer in men by as much as 30 percent, according to a 2005 meta-analysis of six population studies from U.S., Canada, and three Asian countries. Moreover, a cross-national analysis of prostate mortality rates in 42 countries documented significantly lower prostate cancer death rates with soy consumption. In contrast, specialists in men's health find no association between soyfoods and lower sperm concentrations or infertility.

"There are many things a man can do that will probably increase his fertility. Don't smoke, avoid recreational drugs, ask your doctor about the effects of prescription drugs you might be taking, and lose weight if you are obese. Soyfoods are perfectly safe for men and do not impact fertility negatively," explains Lawrence C. (Larry) Ross, M.D., Past President of the American Urological Association and head of urology at the University of Illinois at Chicago.

So how can Americans take advantage of these new research findings? The Soyfoods Association of North America recommends taking these simple steps:

-- Start by looking for soy on the label of the foods and beverages you buy. Soy protein and whole soybeans are listed as ingredients.

-- Look for foods and beverages that carry the soy and heart disease health claim. These products have about one-fourth to one-half of the soy protein needed each day for optimal heart health.

-- Cook with soy ingredients to lower the amount of fat and cholesterol in your diet. This can include using soymilk to bake or make pancakes and substituting soy cheese in salads, sandwiches and as a topping over vegetables.

-- Reduce the saturated fat in your diet by replacing dairy milk with soymilk, or substituting a serving of a frozen dairy free soy desserts for a serving of ice-cream. It's also good to know that most soy yogurts have no saturated fat or cholesterol compared to dairy yogurts.

-- Switch to soy burgers or soy veggie dogs, which have no saturated fat or cholesterol compared to beef franks that have almost 6 grams of saturated fat and 25 mg of cholesterol.

The other important news for health-conscious consumers is there are more soy options available than ever before, which is why today, a third of all Americans are estimated to consume soyfoods or soy beverages once a month or more. Easily digestible, low in calories and saturated fat, and with no cholesterol, soyfoods include soymilk, tofu, cultured soy, non-meat alternatives, frozen dairy free soy treats, soy nuts, soy nut butter, and/or cereals and bars with soy.