Dietary protein intake, animal-to-plant protein ratio and risk of sarcopenia in community-dwelling adults: a 9-year follow-up study.

OBJECTIVE

This study aimed to examine the association between protein intake and risk of sarcopenia, with a specific focus on protein sources, in middle-aged and older adults.

DESIGN

This was a 9-year follow-up study. Dietary protein intake was assessed by a validated FFQ with energy adjustment using the residual method. Sarcopenia was defined by using height-adjusted appendicular lean mass and grip strength. Adjusted OR for sarcopenia were calculated by multivariable logistic regression analysis.

SETTING

Baseline surveys (2011-2014) for the Murakami and Uonuma cohorts assessed body size, lifestyle and medical history. Sarcopenia-related measurements were conducted in 2021-2022 in Murakami, Sekikawa, Uonuma and Minamiuonuma, Japan.

PARTICIPANTS

6232 individuals aged 40-74 years (mean age, 62·4 years; females, 54·8 %).

RESULTS

An inverse association between plant protein intake and sarcopenia was observed in males (Pfor trend = 0·018), although total and animal protein intakes were not. Animal-to-plant protein ratio was U-shaped in its association with sarcopenia; adjusted OR for the lowest and highest quintiles of the ratio compared to the middle quintile were 1·71 (95 % CI: 0·96, 3·07) and 1·97 (95 % CI: 1·10, 3·53), respectively, for males (Pfor quadratic term = 0·017), and 1·93 (95 % CI: 1·06, 3·51) and 1·65 (95 % CI: 0·90, 3·05), respectively, for females (Pfor quadratic term = 0·010).

CONCLUSIONS

An imbalanced intake of plant and animal proteins may increase the risk of sarcopenia, highlighting the importance of balanced protein intake.