Nut consumption and disability-free survival in community-dwelling older adults: a prospective cohort study

Objectives: The relationship between nut intake and disability-free survival (healthy lifespan) in later life is unclear. The objective was to evaluate the association between nut intake and disability-free survival in a cohort of adults aged >= 70 years, and whether this varied according to overall diet quality. Methods: This prospective cohort study involved 9916 participants from the ASPREE Longitudinal Study of Older Persons. Participants completed a 49-item Food Frequency questionnaire from which frequency of nut intake was obtained and were asked to categories usual intake as no/infrequent [never/rarely, 1-2 times/month], weekly [1-2 times/week, often 3-6 times/week] or daily [every day or several times a day]. The outcome measured was a composite of first-event mortality, onset of dementia, or persistent physical disability. Cox proportional hazards regression models, adjusted for socio-demographic factors, health-related and clinical covariates and overall dietary quality were conducted to examine the association between varying levels of nut intake and disability-free survival. Results: Over a mean of 3.9 years of follow-up, the risk of reaching the DFS endpoint were 23% lower (HR 0.77 [0.61-0.98]) for those who consumed nuts daily, when compared to those with no/infrequent nut consumption. Subgroup analysis demonstrated a significant association between daily nut consumption and healthy lifespan among individuals in the second dietary quality tertile (HR 0.71[0.51-0.98]). Conclusion: For community-dwelling adults aged 70 years and over with sub-optimal diets, daily nut consumption is associated with the promotion of healthy lifespan (disability-free survival).