Low flavonoid intake is associated with bilateral hearing impairment in US older adults

This study investigated the association between dietary flavonoid intake and hearing impairment in older adults aged ≥ 70 years, using cross-sectional data from the National Health and Nutrition Examination Survey 2009-2010 and 2017-2018. Flavonoid intake was estimated from two 24-h dietary recalls and categorised as low or high based on the median intake (85·4 mg/d). Hearing impairment was defined using a pure-tone average > 25 dB in one or both ears. Among the 1492 participants, 55·7 % had bilateral hearing impairment, 15·6 % had unilateral hearing impairment and 28·7 % had normal hearing. These categories were mutually exclusive, based on the presence of hearing impairment in one or both ears. After adjusting for sociodemographic, behavioural and dietary covariates, low flavonoid intake was associated with a 45 % greater odds of bilateral hearing impairment (adjusted OR = 1·45; 95 % CI 1·03, 2·04; P = 0·034), but not associated with unilateral impairment. Marginal associations were also observed for specific flavonoid subclasses, including flavan-3-ols and catechins. A significant interaction with age was observed, whereas no significant interactions were detected with race or sex. These findings suggest that low flavonoid intake may be a modifiable dietary factor associated with age-related bilateral hearing loss. Increasing dietary flavonoid consumption may be associated with benefits for sensory health and could play a modest role in reducing the risk of hearing impairment in older adults, though further research is needed to confirm these findings.