Mediterranean Diet and Changes in Sleep Duration and Indicators of Sleep Quality in Older Adults.

Study Objective
To examine the association between adherence to a Mediterranean diet (MD) and changes in sleep duration and sleep quality in older adults.

Methods
We used data from 1596 participants in the Seniors-ENRICA cohort aged ≥ 60 years. MD was evaluated in 2012 with the Mediterranean Diet Adherence Screener (MEDAS) score. Sleep duration (h) and indicators of poor sleep quality were assessed both in 2012 and 2015. Analyses were adjusted for sociodemographic, lifestyle and morbidity variables, and for sleep duration and the number of poor sleep indicators at baseline.

Results
Over a median follow-up of 2.8 years, 12.2% of individuals increased and 8.8% decreased their sleep duration by ≥2 h/night. Compared with those in the lowest tertile of adherence to the MD in 2012, those in the highest tertile showed both a lower risk of a ≥2 h/night increase in sleep duration (odds ratio [OR]: 0.54, 95% confidence interval [CI] 0.34-0.85, p-trend = .01) and of a ≥2 h/night decrease (OR: 0.58, 95% CI 0.35-0.95, p-trend = 0.02) from 2012 to 2015. Being in the highest tertile of MD in 2012 was also associated with lower risk of poor sleep quality at follow-up, the OR (95% CI) for having 2-3 indicators of poor sleep was 0.70 (0.51-0.97) and for ≥4 indicators was 0.68 (0.47-0.99, p-trend = .04). High adherence to the MD was also associated with 56% lower odds of having large changes in sleep duration and ≥2 indicators of poor sleep quality simultaneously (OR: 0.44, 95% CI 0.29-0.68, p trend < .001).

Conclusions
Adherence to a MD pattern was associated with lower risk of changes in sleep duration and with better sleep quality in older adults.