Association between a Planetary Health Diet and changes in intrinsic capacity in older adults: the Seniors-ENRICA cohorts

Background The Planetary Health Diet (PHD) benefits health and the environment. However, its impact on healthy ageing, estimated by intrinsic capacity (IC), remains unexplored. Objective To examine the association between adherence to a PHD Index (PHDI) and changes in IC in older adults. Methods Data were collected from 2519 adults aged ≥60y from the Seniors-ENRICA-1 (2012–15) and 3273 aged ≥65y from the Seniors-ENRICA-2 (2017–19) Spanish cohorts. Food consumption was collected with a dietary history, and the PHDI was based on 15 food groups. IC was measured across six domains: cognition, psychology, vitality, hearing, vision and locomotion (ranged: 0–18, lower score equals better IC). Adjusted multinomial logistic regressions were used, and data from both cohorts were pooled. Results Over a 2.6-year median follow-up, IC worsened for 32.0% of participants, improved for 27.7% and remained stable for 40.3%. Participants in the highest vs lowest tertile of adherence to the PHDI were more likely to improve vs worsen IC [relative risk ratio (RRR) 1.36; 95% confidence interval (95% CI) 1.05–1.77; P-trend = .021]. Higher PHDI scores were significantly associated with improvement vs worsening in the hearing domain (RRR 1.37; 95% CI 1.04–1.82; P-trend = .025). Higher adherence to PHDI’s recommendations regarding nuts (RRR 1.05; 95% CI 1.01–1.09) and starchy vegetables (RRR 1.09; 95% CI 1.01–1.17) were independently associated with improvement vs worsening IC. Conclusion In these older-adult cohorts, higher adherence to the PHDI was associated with improvement in overall IC and in its hearing domain. Adherence to nuts and starchy vegetables recommendations was particularly beneficial.