Soy protein isoflavones, lipids and arterial disease.
ABSTRACT There is convincing evidence that soybean products have beneficial effects on cardiovascular disease risk factors. Interest in understanding which components of the soybean are responsible for the potential benefits on cardiovascular disease risk factors and the magnitude of their effect continues. This review focuses on the scientific literature published during 1999-2001, evaluating the effects of soy protein isolate, soy foods, and purified isoflavones on plasma lipid concentrations and other cardiovascular disease outcomes.
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ABSTRACT: Most individuals at risk for developing cardiovascular disease (CVD) can reduce risk factors through diet and exercise before resorting to drug treatment. The effect of a combination of resistance training with vegetable-based (soy) versus animal-based (whey) protein supplementation on CVD risk reduction has received little study. The study's purpose was to examine the effects of 12 weeks of resistance exercise training with soy versus whey protein supplementation on strength gains, body composition and serum lipid changes in overweight, hyperlipidemic men. Twenty-eight overweight, male subjects (BMI 25-30) with serum cholesterol >200 mg/dl were randomly divided into 3 groups (placebo (n = 9), and soy (n = 9) or whey (n = 10) supplementation) and participated in supervised resistance training for 12 weeks. Supplements were provided in a double blind fashion. All 3 groups had significant gains in strength, averaging 47% in all major muscle groups and significant increases in fat free mass (2.6%), with no difference among groups. Percent body fat and waist-to-hip ratio decreased significantly in all 3 groups an average of 8% and 2%, respectively, with no difference among groups. Total serum cholesterol decreased significantly, again with no difference among groups. Participation in a 12 week resistance exercise training program significantly increased strength and improved both body composition and serum cholesterol in overweight, hypercholesterolemic men with no added benefit from protein supplementation.Journal of the International Society of Sports Nutrition 02/2009; 6:8. · 1.64 Impact Factor
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ABSTRACT: Previous research supports a role for soy protein in reducing serum lipids; however, few studies involved healthy male subjects or focused on soy isoflavones (or did both). The objective was to ascertain the effects of soy protein varying in isoflavone content on serum lipids in healthy young men. Thirty-five males (x +/- SD age: 27.9 +/- 5.7 y) consumed milk protein isolate (MPI), low-isoflavone soy protein isolate (low-iso SPI; 1.64 +/- 0.19 mg aglycone isoflavones/d), and high-isoflavone SPI (high-iso SPI; 61.7 +/- 7.4 mg aglycone isoflavones/d) for 57 d each, separated by 4-wk washout periods, in a randomized crossover design. Blood samples were collected at the beginning and end of each treatment period, and total, LDL, and HDL cholesterol; triacylglycerols; apolipoprotein (apo) B; apo A-I; and C-reactive protein (CRP) were measured in serum. Twenty-four-hour urine samples were collected for 3 consecutive days at the end of each treatment period and analyzed for isoflavones. Urinary isoflavones were significantly greater with consumption of the high-iso SPI than with that of the low-iso SPI or MPI. The differences between the 3 treatments with respect to individual serum lipids were not significant, but the ratios of total to HDL cholesterol, LDL to HDL cholesterol, and apo B to apo A-I were significantly lower with both SPI treatments than with MPI treatment. Soy protein, regardless of isoflavone content, modulates serum lipid ratios in a direction beneficial for cardiovascular disease risk in healthy young men.American Journal of Clinical Nutrition 02/2006; 83(2):244-51. · 6.67 Impact Factor