Impact of the anti‐inflammatory diet on serum high‐sensitivity C‐Reactive protein and new‐onset frailty in community‐dwelling older adults: A 7‐year follow‐up of the Kashiwa cohort study

Abstract

AimChronic inflammation is a pathophysiological cause of age‐related diseases, including frailty. Although diet is a determinant of inflammation, few prospective studies have investigated its role in frailty onset. This study used the dietary inflammatory index to investigate whether a proinflammatory diet affects the incidence of frailty in a 7‐year follow‐up of older Japanese adults.MethodsWe enrolled community‐dwelling older adults without frailty from the 2014 Kashiwa cohort study. Energy‐adjusted dietary inflammatory index (E‐DII) scores were calculated using a brief self‐administered diet history questionnaire. Serum high‐sensitivity C‐reactive protein (hsCRP) levels were measured by immunoassays. Frailty was defined as meeting three of Fried's five phenotypic criteria. Cox regression was used to analyze associations between E‐DII scores and new‐onset frailty after adjusting for relevant confounders.ResultsOverall, 95 (11.7%) of 811 participants (73.7 ± 4.8 years, women 47.3%) developed new‐onset frailty during the 7‐year follow‐up. The baseline E‐DII scores significantly correlated with log‐hsCRP levels, even after adjustment (β = 0.075, P = 0.035). The highest tertile of E‐DII scores (proinflammatory diet) showed a 2.03 times (95% confidence interval, 1.22–3.36) higher risk of new‐onset frailty than that associated with the lowest tertile (P = 0.006). When E‐DII was calculated on the basis of anti‐inflammatory food parameters only, the highest tertile showed a 2.32 times (95% confidence interval, 1.36–3.95) higher risk than that associated with the lowest tertile (P = 0.002).ConclusionsE‐DII scores significantly correlated with serum hsCRP levels. High E‐DII scores caused by low intake of anti‐inflammatory foods are associated with frailty incidence. For community‐dwelling older adults, dietary interventions that lower E‐DII scores (e.g., encouraging dietary fiber intake) may help prevent frailty. Geriatr Gerontol Int ••; ••: ••–•• Geriatr Gerontol Int 2023; ••: ••–••.