Dietary inflammatory index is associated with lung function in healthy older adults

Aging is associated with low-grade chronic inflammation contributing to a decline in lung performance. The Dietary Inflammatory Index (DII) has been introduced to evaluate the inflammatory potential of different diets, which may further affect individuals' respiratory function. This study investigates the association between DII and lung performance in older adults.

This cross-sectional study included 155 adults aged ≥65 y recruited at public gyms in Padua, Italy. Participants were assessed on medical history, biochemical parameters, body composition (through dual energy x-ray absorptiometry), anthropometry, and lung function (by spirometry). Based on individuals' dietary habits, we computed their DII and categorized participants in the lower DII (comprising those in the lowest DII tertile) or the higher DII (comprising those in the highest DII tertiles) groups. The association of DII with forced expiratory volume in the first second (FEV1) and forced vital capacity (FVC) was tested through multivariable linear regression analyses in the total sample and stratified by body mass index (<25 kg/m² versus ≥25 kg/m²).

The mean age of the sample was 71.2 y and 80% were women. Individuals in the higher DII group had FEV1 and FVC values reduced by 0.15 L (95% CI, -0.29 to -0.01 L) and 0.25 L (95% CI, -0.43 to -0.07 L), respectively, as compared with those in the lower DII group. Results seemed to be more marked among participants with excess weight conditions.

Pro-inflammatory diets may affect lung function in fit older people, and this effect may be exacerbated in overweight or obese individuals.