New Year's Resolution: Soy - Good Taste, Good Health

12/01/07 With the advent of a new year, there is good news for Americans making decisions to improve the health of themselves and their families: a growing body of research demonstrates the role of soy foods as part of a healthy diet and lifestyle, especially for the millions of aging consumers at risk of heart disease.

Directly refuting the misleading claims made in the press and internet, the Soyfoods Association of North America (SANA) points to human studies, which continue to support the beneficial role of soy in preventing heart disease and reducing low-density lipoprotein (bad) cholesterol 3-6 percent. Of special significance are new findings to be published in the medical journal Menopause (http://www.menopausejournal.com) from the Johns Hopkins School of Nursing reporting on the Benefits of Soy Trial (BEST). This well-designed study of dietary soy in healthy postmenopausal women with moderately elevated low-density lipoprotein (LDL) cholesterol levels finds that those who ate more soy significantly decreased their total blood and LDL cholesterol levels as well as the LDL particles in their bloodstream while also increasing their beneficial high density lipoprotein (HDL) cholesterol levels. In the study, Dr. Allen, lead researcher cautions that while soy protein alone will not lower cholesterol with the same effectiveness as medications, "the modest effects of soy protein on LDL cholesterol and LDL particle number may be beneficial for heart health in postmenopausal women who do not require statins or other medications to control their levels."

SANA notes the conclusions of researchers from Tulane University Medical School, who in 2006 reviewed multiple human studies involving increased consumption of soy foods and found a significant reduction in total cholesterol, LDL cholesterol and triglycerides, as well as, an increase in the HDL cholesterol levels. Likewise, Dr. James Anderson from the Virginia Medical Center and University of Kentucky reported that soy protein decreased LDL cholesterol levels an average of 5-6 percent across a multiple of human studies. The American Heart Association also reported an average 3 percent reduction in LDL cholesterol and recommended including soy foods, which are cholesterol-free and low in saturated fat, in a heart healthy diet.

"All these studies have consistently found an average 3-6 percent reduction in blood cholesterol with 25 grams of soy protein and continue to confirm the significant scientific consensus that formed the basis for the FDA Health Claim on Soy Protein and Coronary Heart Disease," said Dr. James Anderson. "Although soy foods do not decrease cholesterol as significantly as medications, soy foods do not produce adverse side effects in humans. Even a small drop is important for those with borderline elevated cholesterols and as a complement to medication for those with higher cholesterols. Soy foods are one of the few foods that lower cholesterol and are an important part of an overall heart healthy diet and lifestyle."

SANA also reports that there are no human studies that show soy causes breast cancer in humans. In fact, compelling evidence indicates just the opposite: studies find that women who eat soy foods have lower risks of developing breast cancer and the strongest protective effects occur when soy is consumed during childhood and adolescence. These studies document why Asian women who follow a traditional Asian diet have a much lower breast cancer rate, estimated to be one-fifth that of Western women.

To guide the public, the National Cancer Institute and American Cancer Society advise that breast cancer survivors can include soy foods as part of a healthy diet in moderate amounts.

Also supporting this conclusion is Andrew Weil, MD, who wrote in a November 2006 Time Magazine article "women who have a family history of breast cancer ought to be introducing their kids to soy foods as early as possible. Substituting soy milk for cow's milk is one way to start." Weil goes on to speculate that "the same thing will be shown to hold true for boys; a similar diet may lower their future risk of prostate cancer."

For those with thyroid concerns, SANA points to a recent review of human health research that found no goiters or other thyroid problems in soy users who had ample iodine in their diets (99 percent of Americans meet the dietary recommendations for iodine). Soy, other high-fiber foods, and certain dietary supplements may interfere with medication for hypothyroidism. However, individuals treated for hypothyroidism can include these foods safely but should discuss their diet with their physician.

"Many studies about soy and cancer and soy and thyroid have fed or injected animals with high doses of some of the isoflavones contained in soy," explained Nancy Chapman, Executive Director of SANA. "These findings are not applicable to humans."

There are few foods that alone can boost health -- and soy foods that are cholesterol free, low in saturated fat, high in fiber, iron, potassium, and high quality protein are counted among those healthy foods.