Habitual intake of flavonoid subclasses and incident hypertension in adults

Abstract

Background: Dietary flavonoids have beneficial effects on blood pressure in intervention settings, but there is limited information on habitual intake and risk of hypertension in population-based studies.

Objective: We examined the association between habitual flavonoid intake and incident hypertension in a prospective study in men and women.

Design: A total of 87,242 women from the Nurses' Health Study (NHS) II, 46,672 women from the NHS I, and 23,043 men from the Health Professionals Follow-Up Study (HPFS) participated in the study. Total flavonoid and subclass intakes were calculated from semiquantitative food-frequency questionnaires collected every 4 y by using an updated and extended US Department of Agriculture database.

Results: During 14 y of follow-up, 29,018 cases of hypertension in women and 5629 cases of hypertension in men were reported. In pooled multivariate-adjusted analyses, participants in the highest quintile of anthocyanin intake (predominantly from blueberries and strawberries) had an 8% reduction in risk of hypertension [relative risk (RR): 0.92; 95% CI: 0.86, 0.98; P < 0.03] compared with that for participants in the lowest quintile of anthocyanin intake; the risk reduction was 12% (RR: 0.88; 95% CI: 0.84, 0.93; P < 0.001) in participants ≤60 y of age and 0.96 (0.91, 1.02) in participants >60 y of age (P for age interaction = 0.02). Although intakes of other subclasses were not associated with hypertension, pooled analyses for individual compounds suggested a 5% (95% CI: 0.91, 0.99; P = 0.005) reduction in risk for the highest compared with the lowest quintiles of intake of the flavone apigenin. In participants ≤60 y of age, a 6% (95% CI: 0.88, 0.97; P = 0.002) reduction in risk was observed for the flavan-3-ol catechin when the highest and the lowest quintiles were compared.

Conclusions: Anthocyanins and some flavone and flavan-3-ol compounds may contribute to the prevention of hypertension. These vasodilatory properties may result from specific structural similarities (including the B-ring hydroxylation and methyoxylation pattern).

FIGURE 1.

Major contributors to dietary intake by subclass of flavonoid in the Nurses' Health Study (NHS 1), the Nurses' Health Study 2 (NHS 2), and the Health Professionals Follow-Up Study (HPFS).

FIGURE 2.

A–D: Incident hypertension by quintiles (Q) of anthocyanin intake (stratified by age <60 y). NHS II, Nurses' Health Study II; NHS I, Nurses' Health Study; HPFS, Health Professionals Follow-Up Study. P for trend < 0.001.

FIGURE 3.

Common flavonoid structures. Catechol flavonoids and their methyl- and 4′-hydroxy derivatives. A: Basic catechol flavonoid structure. B: Structure of apocynin, which is a vasoactive drug (similar in structure to methylated B-ring flavonoids). C: Catechol flavonoids in the diet (anthocyanin, cyanidin; flavan-3-ol, catechin) and a naturally occurring methyl derivative (anthocyanin, peonidin) in plants. D: 4′ Hydroxy flavonoids (anthocyanin, pelargonidin; flavone, apigenin).