Associations between dietary patterns and sarcopenia: insights from cross-sectional and Mendelian randomization...

Sarcopenia is defined as a progressive and generalized skeletal muscle disorder characterized by the accelerated loss of muscle mass and function. Current studies have revealed the significant impact of some dietary factors on the development and progression of sarcopenia. However, these studies often focused on single nutrients but little had examined complete dietary strategies. Thus, comprehensive evaluations of diverse dietary factors in larger populations are crucial for effectively adjusting diets to delay sarcopenia progression, enhancing quality of life and independence in the elderly.

We conducted a cross-sectional analysis to assess the potential correlation between various dietary factors and sarcopenia based on the population data from the UK Biobank. This analysis employed multivariate logistic regression models adjusted for different covariates (demographic data including age, sex, ethnics, etc., and potential confounders including smoking status, activity group, body mass index, etc.). Furthermore, to evaluate the robustness of our findings, we performed sub-analyses and calculated the Variance Inflation Factor. To investigate the causal influence of dietary factors on sarcopenia-related phenotypes, including low hand grip strength and appendicular lean mass (ALM), we conducted a Mendelian Randomization (MR) analysis. The analytic methods of MR were selected based on the outcomes of sensitivity analyses.

In the cross-sectional analysis, a total of 211,027 participants were included in the final analysis, with a mean age of 56 years, comprising 104,271 females and 106,756 males. We identified significant correlations between the frequency and type of food intake and sarcopenia. For probable sarcopenia diagnosed by grip strength, a higher intake frequency of oily fish is negatively correlated with sarcopenia risk, whereas processed meat shows a positive correlation. Preference for FloraPro-Active/Benecol in spreads also relates to a reduced risk. Preliminary findings indicate correlations between tea (OR = 1.02, p < 0.01), coffee (OR = 1.02, p < 0.01), fresh fruit intake (OR = 1.01, p < 0.01), and probable sarcopenia. For confirmed sarcopenia diagnosed by grip strength and ALM, a higher intake frequency of processed meat could increase sarcopenia risk and preference for Bran cereal in cereal type and wholemeal or wholegrain in bread type also related to a reduced risk. The MR analysis revealed that coffee (ground coffee (OR = 3.44, p < 0.0035), instant coffee (OR = 2.69, p < 0.015), decaffeinated coffee (OR = 3.94, p < 0.0004)) intake significantly increased the risk of low grip strength, while water (OR = 1.06, p < 0.000398) and fruit (OR = 1.10, p < 0.0065) intake enhance ALM. Conversely, psychoactive drinks (OR = 0.91, p < 0.00001), alcohol (OR = 0.906, p < 0.0012), and decaffeinated coffee (OR = 0.65, p < 0.0047) decreased ALM. These results have undergone sensitivity analysis validation.

Our analysis using UK Biobank data explored associations between dietary factors and sarcopenia. We found strong links between probable sarcopenia and the intake of oily fish, processed meat, lamb, and coffee, whereas processed meat remained significantly related with confirmed sarcopenia. Preference for specific foods, such as FloraPro-Active/Benecol spreads, Bran cereal and wholemeal or wholegrain bread were associated with reduced risk. MR confirmed the causal effects of coffee intake on low hand grip strength and ALM. Our study provides insights for dietary strategies in sarcopenia patients, though further research is needed to validate and explore these mechanisms.