Food as medicine: white and whole-grain bread consumption in relation to sarcopenia among older adults, insights from the Birjand Longitudinal Aging Study (BLAS)

This study aimed to examine the association between energy-adjusted consumption patterns of different types of bread, including whole-grain and white bread, and the risk of sarcopenia in older adults. In this cross-sectional study, sarcopenia was assessed using three tests: appendicular skeletal muscle mass (ASMM), handgrip strength, and gait speed, in 1,325 older adults from the Birjand Longitudinal Aging Study (BLAS), conducted between September 2018 and April 2019. Bread consumption was evaluated through a semi-quantitative food frequency questionnaire. Consumption patterns of whole-grain and white bread were identified via factor analysis, adjusted for energy intake, and categorized into quartiles. In total, 28% of participants had sarcopenia. The highest quartile of the white bread pattern was associated with a 56% increased risk of low ASMM (OR: 1.56; 95% CI: 1.03 to 2.37, P = 0.04) and a twofold increase in the risk of low handgrip strength (OR: 2.00; 95% CI: 1.47 to 2.74, P < 0.001). In contrast, higher adherence to the whole-grain bread pattern significantly reduced the risk of low handgrip strength (OR: 0.68; 95% CI: 0.48 to 0.95, P = 0.02). No significant association was found between either bread pattern and gait speed. Higher whole-grain bread intake was inversely associated with sarcopenia (OR: 0.63; 95% CI: 0.44 to 0.90, P = 0.01), while white bread intake increased the odds (OR: 1.64; 95% CI: 1.14 to 2.37, P = 0.01). Overall, greater whole-grain bread consumption was linked to better muscle strength, whereas white bread intake was associated with weaker muscles, muscle loss, and sarcopenia in older adults. Given the cross-sectional nature of this study, further research is needed to explore the underlying mechanisms and clarify the direction of these associations.