[Relationship between dietary soy isoflavones and blood lipid levels in 40 - 65 year-olds in Guangzhou]

Abstract

Objective: To study the relationship between dietary soy isoflavones and blood lipids among residents of 40 - 65 years old, in Guangzhou.

Methods: Dietary soy isoflavones and other nutrients intakes were assessed with quantitative food frequency questionnaire (FFQ). Total cholesterol (TC), triglycerides (TG), HDL cholesterol (HDL-C) and LDL cholesterol (LDL-C) in plasma were measured with colorimetry.

Results: Ranges of dietary soy isoflavones intake among 134 males and 261 females were from 0 mg/day to 61.96 mg/day and 0 mg/day to 82.52 mg/day, with means of 11.95 mg/day, 14.90 mg/day, respectively. After adjusted for total energy intake and fat percent energy, differences of TC, LDL-C in total population and TC in women were statistically significant between groups (P value was 0.002, 0.008, 0.004, respectively) and dose-effect relationships (P value was < 0.001, 0.012, 0.001, respectively) were observed between dietary soy isoflavones intake and the upper mentioned three indices. Compared with the low-intake group, these three indices lowered 7.06%, 10.13% and 7.48%, respectively in high-intake group. Critical significance of LDL-C was observed both in women and men between groups. Further controlled for age, BMI and WHR, no obvious change of the results was observed.

Conclusion: Moderate intakes of soy isoflavone as part of a regular diet seemed to be associated with favorable blood lipid levels.