Effects of dietary intake of soy protein and isoflavones on cardiovascular disease risk factors in high risk, middle-aged men in Scotland

• Published in: Journal of the American College of Nutrition Vol. 23; no. 1; pp. 85 - 91
• Main Authors: Sagara, M, Kanda, T, Njelekera, M, Teramoto, T, Armitage, L, Birt, N, Birt, C, Yamori, Y
• Format: Journal Article
• Language: English
• Published: United States 01.02.2004
• Subjects: Blood Pressure - drug effects; cardiovascular diseases; Cardiovascular Diseases - blood; Cardiovascular Diseases - epidemiology; Cardiovascular Diseases - prevention & control; Cholesterol - blood; Double-Blind Method; food intake; Humans; isoflavones; Isoflavones - administration & dosage; Isoflavones - urine; Male; Middle Aged; Placebos; Risk Factors; Scotland - epidemiology; soy protein; Soybean Proteins - administration & dosage; Triglycerides - blood; Scotland
• ISSN: 0731-5724; 1541-1087
• DOI: 10.1080/07315724.2004.10719347

Objective: To investigate the effects of soy protein and isoflavones on blood pressure (BP) and cholesterol levels among high risk middle-aged Scottish men. Design: A randomized, double-blind, placebo-controlled, parallel-group dietary intervention study Setting: Inhabitants on Isles of Lewis and Harris in Scotland Subjects: Sixty-one men with relatively higher BP and/or total cholesterol (TC) levels aged 45 to 59 went through the dietary intervention. Intervention: Diets containing at least 20 g of soy protein and 80 mg of isoflavones were compared to the placebo diets. Intervention period was 5 weeks duration. Results: Significant difference was found in 24-hour urinary isoflavone excretion between the two groups after intervention. Significant reductions from the baselines were observed in systolic BP (SBP) and diastolic BP (DBP), TC and non-high density lipoprotein cholesterol (non-HDL-C) in the soy-containing diet group, but not in the olive oil containing active placebo group. Significant increases in high density lipoprotein cholesterol (HDL-C) were observed in both groups. Conclusion: Dietary intakes of soy protein (at least 20 g) and isoflavones (at least 80 mg) for 5 weeks would be effective in reducing CHD risk among high-risk, middle-aged men.