Dietary Inflammatory Index and cardiorespiratory fitness among older adults living in the community: a cross-sectional analysis

Abstract The optimal dietary recommendation for healthy ageing remains unclear. This study examined the association between the Dietary Inflammatory Index (DII) and cardiorespiratory fitness (CRF) in Chinese community-dwelling older adults. Data were drawn from the Guangzhou Nutrition and Health Study’s 3rd and 4th follow-up visits (2017–2021). DII was calculated from a Seventy nine-item validated FFQ, and CRF was assessed on a cycle ergometer using a submaximal constant work rate protocol. VO 2 max was estimated via the Åstrand-Ryhming Nomogram with age correction, and relative intensity was expressed as percentage of predicted maximal heart rate (%HRmax). Favourable CRF was defined as sex-specific VO 2 max in the top quartile or %HRmax < 85 %. Among 906 participants (615 women, 291 men; mean age 65·9 ± 5·4 years), those in the lowest DII tertile (anti-inflammatory diet) had higher VO 2 max than those in the highest tertile ( P -trend = 0·048) and greater odds of favourable CRF (OR 1·81, 95 % CI 1·22–2·70), while no significant associations were observed for %HRmax ( P -trend = 0·356; OR 1·31, 95 % CI 0·94–1·84). Associations between lower DII and higher VO 2 max were stronger among physically active participants ( P -interaction = 0·049). Compared with consistently high DII, both transition to a low-inflammatory diet (OR 3·01, 95 % CI 1·20–7·51) and persistent adherence to such a diet (OR 2·49, 95 % CI 1·28–4·87) were associated with favourable CRF. These findings suggest that an anti-inflammatory diet is associated with better CRF in older adults, with potential synergistic benefits from physical activity. Trial registration: This trial was registered at clinicaltrials.gov as NCT03179657.