Nut Intake, Functional Limitations, and Quality of Life in Older Adults: Findings From NHANES 2003-2012.

BACKGROUND

Increased nut consumption has positive effects on physical and cognitive function, but whether these translate into lower functional limitations in older adults is unknown. The aim of this study was to investigate the association between nut intake, functional limitations, the severity of these limitations and health-related quality of life (HRQOL) in older adults.

METHODS

This cross-sectional study included data from 5807 adults (53.4% female) aged 60 years and older who participated in the US National Health and Nutrition Examination Survey (NHANES) between 2003 and 2012. Nut intake was assessed using two 24-h dietary recalls. Functional limitations were assessed using the NHANES Physical Functioning Questionnaire. Quality of life was evaluated using the four-question HRQOL-4 questionnaire. Negative binomial regression, linear regression and logistic regression analyses were used to examine associations between nut intake and both functional limitations and quality of life.

RESULTS

Nut consumption (> 0 g/day) was associated with significantly fewer functional limitations (β = -0.12; 95% CI: -0.24, -0.01; p = 0.048) and lower severity of these limitations (β = -0.67; 95% CI -1.11, -0.23; p = 0.004) compared to no consumption. Compared to nonconsumers, nut consumers (> 0 g/day) also had lower odds of reporting poor physical health (OR = 0.81; 95% CI 0.68, 0.98; p = 0.027) and activity limitations (OR = 0.72; 95% CI 0.55, 0.95; p = 0.023). When participants were categorised by intake level (nonconsumers, < 6.9 g/day, and ≥ 6.9 g/day), consuming ≥ 6.9 g/day was associated with fewer (β = -0.19; 95% CI: -0.32, -0.06; p = 0.004) and lower severity of functional limitations (β = -0.84; 95% CI: -1.30, -0.37; p = 0.001) compared to no consumption. Intake ≥ 6.9 g/day was also associated with lower odds of poor general health (OR = 0.76; 95% CI: 0.60, 0.906; p = 0.023), poor physical health (OR = 0.74; 95% CI: 0.57, 0.97; p = 0.027) and limitations in daily activities (OR = 0.61; 95% CI: 0.46, 0.82; p = 0.001).

CONCLUSIONS

Consumption of nuts, particularly at above-median levels, in older adults may be linked with experiencing fewer functional limitations, lower severity of these limitations and fewer general and physical unhealthy and inactive days.