Association between dietary intake of flavonoid and bone mineral density in middle aged and elderly Chinese women and men

This large cross-sectional study examined the associations of dietary intakes of total flavonoids and their subtypes with bone density in women and men. We found that greater flavonoid intake was associated with higher bone density in women but not in men. Studies in vitro and in animal models suggest a potential effect of flavonoids on bone health. Few studies have examined the association between the habitual intake of flavonoids and bone mineral density (BMD) in humans. The cross-sectional study recruited 2,239 women and 1,078 men. A semiquantitative food frequency questionnaire was administered in face-to-face interviews to assess habitual dietary flavonoid intake using food composition databases. BMD was measured over the whole body (WB) and in the femoral neck (FN) and lumbar spine (LS) by dual-energy X-ray absorptiometry (DXA). After adjusting for covariates, women who consumed higher total flavonoids, and the subtypes of flavonols, flavan-3-ols, flavones, and proanthocyanidins tended to have greater BMD at the WB, LS, and FN (all P-trend < 0.05). Women in the highest (vs. the lowest) quartile of total flavonoids intake had 0.020 (1.91 %), 0.021 (2.51 %), and 0.013 (1.99 %) g/cm(2) greater BMD at the whole body, LS, and FN, respectively. For the subtypes of flavonoids, the corresponding differences in BMD (in g/cm(2)) were 0.012-0.021 (flavan-3-ols), 0.013-0.020 (flavonols), 0.016-0.019 (flavones), and 0.014-0.016 (proanthocyanidins), respectively. A higher intake of flavonones was associated with a greater BMD at the whole body (P-trend 0.041) and the FN (P-trend 0.022). In men, there were no significant positive associations between the consumption of total flavonoids and the subclasses and BMD at any sites. Dietary flavonoids intake was positively associated with BMD in women. Further large studies are needed to clarify this issue in men.