This study examines the relationship between long-term intake of six ﬂavonoid classes and incidence of CVD and CHD, using a comprehensive ﬂavonoid database and repeated measures of intake, while accounting for possible confounding by components of a healthy dietary pattern. Flavonoid intakes were assessed using a FFQ among the Framingham Offspring Cohort at baseline and three times during follow-up. Cox proportional hazards regression was used to characterise prospective associations between the natural logarithms of ﬂavonoid intakes and CVD incidence using a time-dependent approach, in which intake data were updated at each examination to represent average intakes from previous examinations. Mean baseline age was 54 years, and 45 % of the population was male. Over an average 14·9 years of follow-up among 2880 participants, there were 518 CVD events and 261 CHD events. After multivariable adjustment, only ﬂavonol intake was signiﬁcantly associated with lower risk of CVD incidence (hazard ratios (HR) per 2·5-fold ﬂavonol increase = 0·86, Ptrend = 0·05). Additional adjustment for total fruit and vegetable intake and overall diet quality attenuated this observation (HR = 0·89, Ptrend = 0·20 and HR = 0·92, Ptrend = 0·33, respectively). There were no signiﬁcant associations between ﬂavonoids and CHD incidence after multivariable adjustment. Our ﬁndings suggest that the observed association between ﬂavonol intake and CVD risk may be a consequence of better overall diet. However, the strength of this non-signiﬁcant association was also consistent with relative risks observed in previous meta-analyses, and therefore a modest beneﬁt of ﬂavonol intake on CVD risk cannot be ruled out.
Bibliographical noteCopyright © The Authors 2015 This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited.
- Flavonoid intake
- Observational study