Intake of Flavonols and Flavones and Risk of Coronary Heart Disease in Male Smokers

Abstract

Flavonols and flavones are antioxidant polyphenolic compounds found in tea, vegetables, fruits, and wine. In experimental studies they have been effective free radical scavengers, metal chelators, and antithrombotic agents. In the few epidemiologic studies of these agents, some have suggested an inverse association between intake of flavonols and flavones and the risk of cardiovascular disease. Our study population comprised 25,372 male smokers, 50-69 years of age, with no previous myocardial infarction. They were participants of the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study, which was a randomized, double-blind, placebo-controlled trial with daily supplementation of alpha-tocopherol (50 mg per day) and/or beta-carotene (20 mg per day). The men completed a validated dietary questionnaire at baseline. After 6.1 years of follow-up, there were 1,122 nonfatal myocardial infarctions and 815 coronary deaths. In the multivariate model, the relative risk of nonfatal myocardial infarction was 0.77 (95% confidence interval = 0.64-0.93) among men in the highest (median 18 mg per day) compared with the lowest (median 4 mg per day) quintile of flavonol and flavone intake. The respective relative risk for coronary death was 0.89 (95% confidence interval = 0.71-1.11). Thus, intake of flavonols and flavones was inversely associated with nonfatal myocardial infarction, whereas there was a weaker association with coronary death.

The relation between dietary flavonol intake and coronary heart disease mortality: a meta-analysis of prospective cohort studies

“…Moreover, the bioavailability of flavonols from tea has been shown to be only about 50% of that from other sources such as onions (Hollman & Katan, 1999) suggesting that flavonol intake from tea may not be as beneficial as that derived from fruits, vegetables and red wine. In support of this, subgroup analyses of specific sources of flavonols with CHD mortality indicated that tea consumption was unrelated to CHD risk after adjustment for dietary factors Yochum et al, 1999) , whereas high intakes of flavonols from vegetable sources, such as broccoli and onions, were significantly and inversely associated with CHD mortality Yochum et al, 1999;Hirvonen et al, 2001). …”

“…Excluding this study from the pooled estimate had little impact on the overall effect size (RR ¼ 0.77, 95% CI 0.66-0.90). Additional sensitivity analyses indicated that the point estimate and CI for the risk reduction were not significantly altered with the exclusion of any individual study although the reduction of risk to 0.74 (95% CI 0.63-0.87) with the exclusion of the study by Hirvonen et al (2001) suggests that this cohort, which had the largest number of events, was the most influential.…”

MAPK signaling in neurodegeneration: influences of flavonoids and of nitric oxide

“…However, flavonoids exhibit various effects on mammalian cells with interesting implications for inflammation [133], cardiovascular disease [81,83] and cancer [58] involving the modulation of redox functions, calcium homeostasis [227], the activity of various enzyme systems, proliferation and differentiation, and the response to a variety of stimuli (reviewed in [134]). The effects of flavonoids are often pictured as beneficial for cell survival, preventive against oxidative insults and anti-carcinogenic.…”

Urinary excretion of 13 dietary flavonoids and phenolic acids in free-living healthy subjects – variability and possible use as biomarkers of polyphenol intake

“…Both experimental and epidemiological evidence support a role of polyphenols in the prevention chronic diseases and more particularly cardiovascular diseases and cancers . Polyphenol intake has been related to disease in epidemiological studies, and especially inverse associations with cardiovascular risk have been observed (Hertog et al, 1993;Knekt et al, 1996;Hirvonen et al, 2001).…”