Soy Protein May Be as Effective as Statins for Lowering Cholesterol

(July 22, 2003) – Adding soy protein, viscous fiber, and nuts can be as effective for lowering cholesterol as adding a statin to a low saturated fat diet, according to the results of a randomized controlled trial published in the July 23/30 issue of The Journal of the American Medical Association.

"Current dietary recommendations focusing on diets low in saturated fat have been expanded to include foods high in viscous fibers (eg, oats and barley) and plant sterols," write David J. A. Jenkins, MD, from St. Michael's Hospital in Toronto, Ontario, Canada, and colleagues. "These guidelines, together with additional suggestions to include vegetable protein foods (soy) and nuts (almonds), appear to reduce LDL-C [low-density lipoprotein cholesterol] levels similarly to the initial therapeutic dose of a first generation statin."

In this four-week study, 46 healthy, hyperlipidemic adults, including 25 men and 21 postmenopausal women (average age, 59 years; average body mass index, 27.6), were randomized to one of three diets. The control diet was very low in saturated fat, based on milled whole-wheat cereals and low-fat dairy foods, such as skim milk, fat-free cheese, and yogurt. The statin group received the same diet plus lovastatin, and the dietary portfolio group received a diet high in plant sterols (1g/1,000 kcal), soy protein (21.4 g/1,000kcal), viscous fibers (9.8 g/1,000kcal), and almonds (14 g/1,000 kcal).

LDL-C decreased by 8.0% in the control group, 30.9% in the statin group, and 28.6% in the dietary portfolio group. C-reactive protein decreased by 10.0%, 33.3%, and 28.2%, respectively. The significant reductions seen in the statin and dietary portfolio groups were significantly different from changes in the control group, and the efficacy of the dietary portfolio treatment was not significantly different from that of the statin treatment.

"In this study, diversifying cholesterol-lowering components in the same dietaryportfolio increased the effectiveness of diet as a treatment of  hypercholesterolemia," the authors write. "Using the experience gained, furtherdevelopment of this approach may provide a potentially valuable dietary option for cardiovascular disease risk reduction in primary prevention."

The Canada Research Chair Endowment of the federal government of Canada, the Canadian Natural Sciences and Engineering Research Council of Canada, Loblaw Brands, Ltd., the Almond Board of California, and Unilever Canada supported this study. Dr. Jenkins holds a Canada Research Chair funded by the federal government of Canada, and he has received research grants and/or other financial support from the Almond Board of California, Loblaw Brands, Ltd., Yves Fine Foods (now Hain-Celestial Group), Unilever Canada, and Protein Technologies, Inc. (now Solae).

In an accompanying editorial, James W. Anderson, MD, from the University of Kentucky in Lexington, emphasizes the importance of dietary management in treating all common lipid disorders.

"Dietary management is an essential part of the treatment for lipid disorders, although adherence to strict and intensive dietary interventions requires motivation by patients, encouragement by physicians, and, perhaps, counseling by dietitians and nutrition experts," he writes. "For most patients, dietary intervention should be the first line of therapy (perhaps for six to 12 weeks) before introducing pharmacotherapy for hyperlipidemia."