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ARS Home » Northeast Area » Boston, Massachusetts » Jean Mayer Human Nutrition Research Center On Aging » Research » Publications at this Location » Publication #147410
Title: THE BENEFICIAL EFFECTS OF SOY PROTEIN ON ELECTROPHORETIC CHARACTERISTICS OF LDL PARTICLES ARE INDEPENDENT OF ITS ISOFLAVONE COMPONENT

Author
item DESROCHES, SOPHIE - LAVAL UNIVERSITY
item MAUGER, JEAN-FRANCOIS - LAVAL UNIVERSITY
item AUSMAN, LYNNE - HNRCA
item LICHTENSTEIN, ALICE - HNRCA
item LAMARCHE, BENOIT - LAVAL UNIVERSITY

Submitted to: Journal of Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/3/2003
Publication Date: 3/1/2004
Citation: DESROCHES, S., MAUGER, J., AUSMAN, L.M., LICHTENSTEIN, A.H., LAMARCHE, B. THE BENEFICIAL EFFECTS OF SOY PROTEIN ON ELECTROPHORETIC CHARACTERISTICS OF LDL PARTICLES ARE INDEPENDENT OF ITS ISOFLAVONE COMPONENT. JOURNAL OF NUTRITION. 2004;134:574-9.

Interpretive Summary: Soy protein has been associated with a decrease in the risk of developing heart disease. Similar claims have been made for soy-derived isoflavones. One potential mechanism for these observations may be related to the characteristics of low-density lipoprotein (LDL) particles, sometimes referred to as "bad" cholesterol. Small-dense LDL particles are thought to be more atherogenic (increase heart disease risk) than larger LDL particles. The effect of soy protein and/or soy derived isoflavones on the LDL particle size has yet to be determined. The objective of this study was to investigate the effect of soy protein and/or soy derived isoflavones consumption on LDL particles size and distribution. Eighteen females and 18 males consumed each of 4 experimental diets in random order for 6-week periods. Diets contained twenty-five grams protein/1000 kcal animal or isolated soy protein, each containing either trace or 50 mg isoflavones/1000 kcal. The soy protein containing diets were associated with a significant increase in LDL peak particle size relative to animal protein. The soy protein containing diets also significantly decreased the relative and absolute cholesterol concentrations in LDL particles and increased cholesterol levels in LDL particles relative to animal protein. Soy-derived isoflavones had no significant effect on these LDL particle characteristics. Soy protein has beneficial effects on various electrophoretic characteristics of LDL particles and these effects are independent of its isoflavones component.

Technical Abstract: LDL particle diameter may be modulated through dietary interventions, particularly by modifying the fat and carbohydrate content of the diet, but little is known about the effects of other dietary constituents. No study to date has investigated the effect of soy protein and isoflavones on the cholesterol distribution among different LDL subclasses. The objective of the present study was to assess the independent effect of soy protein relative to animal protein and isoflavones on various electrophoretic characteristics of LDL particles. LDL particles were characterized by polyacrylamide gradient gel electrophoresis in 36 moderately hypercholesterolemic subjects (LDL cholesterol > 3.36mmol/L). All subjects consumed each of the four diets (soy protein depleted of isoflavones, soy protein enriched in isoflavones, animal protein with no added isoflavones, and animal protein with added isoflavones), for six weeks. Soy protein significantly decreased the proportion and the cholesterol concentrations of small LDL particles ( <255 angstroms, p=0.0002 and p=0.0005, respectively) and increased the proportion and the cholesterol concentrations of large LDL particles ( >260 angstroms, p=0.0003 and p=0.0242, respectively) relative to animal protein. Isoflavones had no significant effects on LDL particles characteristics. Soy protein has beneficial effects on various electrophoretic characteristics of LDL particles that are independent of its isoflavones component.