Association between Mushroom Consumption and Digit Span Performance among Middle-aged and Older Community-dwelling Japanese: The NILS-LSA Project

Abstract

Cognitive decline, particularly in short-term and working memory, is a major concern in aging populations. Mushrooms contain bioactive compounds that may support brain health, but the association between mushroom consumption and specific memory functions remains unclear. This study investigated the association between mushroom intake and digit span performance among 3,162 Japanese adults (mean age 57.9 ± 13.1 years; mean follow-up duration 10.5 ± 6.1 years) from the National Institute for Longevity Sciences-Longitudinal Study of Aging (2002−2022). Mushroom consumption (g/day) at baseline was assessed using 3-day dietary records. Short-term and working memory, which are fundamental components of general cognitive ability, were evaluated using forward and reverse digit span scores (range: 0−14 points for each) from the Wechsler Adult Intelligence Scale–Revised. Mixed-effects models with splines, adjusted for demographic, dietary, health, and socioeconomic factors, revealed significant non-linear associations: higher mushroom consumption was linked to better performance on forward digit span (full-adjusted spline terms β1=1.192, p=0.0117; β2=2.549, p=0.0235) and reverse digit span (full-adjusted spline terms β1=0.974, p=0.0352; β2=2.209, p=0.0447) tests, with benefits most pronounced at moderate to high intake levels. These findings suggest that regular mushroom consumption, measured in grams per day, may enhance short-term and working memory in middle-aged and older adults, highlighting a potentially simple dietary approach to support cognitive function during aging.