# Dietary Patterns and Their Association with Cognitive Function: A Stratified Analysis by Sleep Duration in Japanese Older Adults

## TL;DR

A study in Japan found that diverse and balanced diets are linked to better cognitive function in older adults, regardless of sleep duration.

## Contribution

The study identifies three dietary patterns and examines their cognitive associations stratified by sleep duration in older Japanese adults.

## Key findings

- Diverse and balanced diets were linked to lower odds of poor cognitive function compared to restricted diets.
- The associations were consistent across different sleep durations, with no significant interaction effects.
- Integrated lifestyle interventions targeting both nutrition and sleep are recommended for aging populations.

## Abstract

What are the main findings?
Three dietary patterns—diverse, balanced, and restricted—were identified among older Japanese adults.Compared with the restricted pattern, both the diverse and balanced patterns were associated with lower odds of poor subjective cognitive function after adjustment.These associations were generally consistent across sleep-duration strata, and formal interaction testing did not support significant effect modification by sleep duration.

Three dietary patterns—diverse, balanced, and restricted—were identified among older Japanese adults.

Compared with the restricted pattern, both the diverse and balanced patterns were associated with lower odds of poor subjective cognitive function after adjustment.

These associations were generally consistent across sleep-duration strata, and formal interaction testing did not support significant effect modification by sleep duration.

What are the implications of the main findings?
Promoting dietary diversity and balance may help support subjective cognitive health in community-dwelling older adults.Community-based programs may benefit from integrating nutrition guidance with sleep-health education, while recognizing that evidence for sleep-specific modification of diet–cognition associations was limited in this study.

Promoting dietary diversity and balance may help support subjective cognitive health in community-dwelling older adults.

Community-based programs may benefit from integrating nutrition guidance with sleep-health education, while recognizing that evidence for sleep-specific modification of diet–cognition associations was limited in this study.

Background/Objective: This study investigated the associations between dietary patterns and subjective cognitive function among older Japanese adults and examined whether these associations differed according to sleep duration. Methods: This longitudinal cohort study was conducted using data from the Community Empowerment and Care study (2017–2020). Data were obtained from the Community Empowerment and Care Study of the T-Village, Aichi Prefecture, Japan. Latent class analysis was used to identify dietary patterns based on the intake frequencies of seven food groups. Logistic regression models assessed the associations between dietary patterns and subjective cognitive function stratified by sleep duration (optimal: 7–8 h; unfavorable: <7 or >8 h). Results: Three dietary patterns were identified (diverse, balanced, restricted). Compared with the restricted pattern, the diverse (odds ratio = 0.13, 95% confidence interval: 0.07–0.26; p < 0.0001) and balanced patterns (odds ratio = 0.33, 95% confidence interval: 0.18–0.62; p = 0.0006) were associated with lower odds of poor subjective cognitive function. Associations were broadly similar across sleep groups, and interaction testing was not significant. Conclusions: Dietary quality was associated with better subjective cognitive function, particularly among older adults with unfavorable sleep duration. The study findings underscore the need for integrated lifestyle interventions that target both nutrition and sleep in aging populations.