Intervention data suggest a cardioprotective role for supplemental
isoflavones; however, few studies have examined the
cardiovascular disease (CVD) benefit of usual dietary
isoflavone intake. This cross-sectional study examined the association between usual dietary
isoflavone intake and CVD risk factors, including
lipids and
lipoproteins, body mass index (BMI) and fat distribution, blood pressure,
glucose and
insulin. Subjects were postmenopausal women (n = 208) aged 45-74 y, who attended screening and baseline visits for a randomized, double-blind, placebo-controlled trial examining the effects of
isoflavone use. At screening, total
cholesterol,
triglycerides,
HDL cholesterol and
LDL cholesterol were measured, and demographic, behavioral and menopausal characteristics were assessed. One month later, dietary intake over the past year was assessed with a standardized questionnaire. Anthropometric measurements and blood pressure were obtained, and a 75-g oral
glucose tolerance test was administered.
Isoflavone consumption did not vary by age, exercise, smoking, education or years postmenopausal. Women with high
genistein intake had a significantly lower BMI (P-trend = 0.05), waist circumference (P-trend = 0.05) and fasting
insulin (P-trend = 0.07) than those with no daily
genistein consumption. In adjusted analyses,
genistein,
daidzein and total
isoflavone intake were each positively associated with
HDL cholesterol (P = 0.05) and inversely associated with postchallenge
insulin (P = 0.05). These data suggest a protective role for dietary soy intake against CVD in postmenopausal women.