Association Between Working Memory at Age 4 Years and Night Sleep Duration and Yogurt Intake Frequency at Age 1 Year

TL;DR

A study found that yogurt intake and longer night sleep at age 1 may be linked to better working memory at age 4.

Contribution

The study identifies novel associations between early yogurt consumption and night sleep with later working memory performance.

Findings

Night sleep duration at age 1 is significantly associated with working memory at age 4.

Yogurt intake frequency at age 1 is significantly linked to working memory performance at age 4.

Yogurt intake frequency is not correlated with sleep duration in this sample.

Abstract

Background/Objectives: This cohort study examined the effects of sleep durations (night, day, and total daily) at ages 1, 1.5, and 3 years on working memory (WM) assessed at age 4, measured using forward digit span. Methods: Because frequency of yogurt intake at 1 year has been shown to affect sleep duration at 3 years, we also accounted for the association between frequency of yogurt intake at 1 year and sleep duration, based on a recent study indicating positive effects of yogurt on sleep. The study included 164 mother–child pairs observed from ages 1 to 4. Results: Spearman correlations and hierarchical multiple regression analyses revealed that both night sleep duration and yogurt intake at age 1 were significantly associated with WM performance at age 4. In this sample, however, yogurt intake was not correlated with sleep duration. Conclusions: To a limited degree, both yogurt intake frequency and night sleep duration at 1 year were associated with WM performance at 4 years, indicating that frequent yogurt intake at 1 year and longer night sleep duration may lead to higher WM performance at 4 years.