Do dietary habits, dietary patterns, and macronutrient intakes affect aging? Multi-dimensional evidence from UK Biobank

The role of diet in aging is pivotal, yet existing research offers inconsistent findings regarding the impact of specific diets on human aging. We conducted a systematic investigation into the relationship between dietary factors and aging, exploring potential causal links between macronutrient intake and aging. Utilizing data from the UK Biobank baseline survey and a 24-hour dietary assessment survey, we employed a High-dimensional Fixed Effects (HDFE) model to examine dietary factors association with aging. Multivariable Mendelian Randomization (MVMR) and Semiparametric Nonlinear Mendelian Randomization (NLMR) techniques assessed causal links between macronutrient consumption and aging. HDFE analysis indicated that a healthier diet was generally linked to better aging outcomes, with various dietary components correlating with aging. For instance, plant-based food intake was associated with increased telomere length and/or reduced phenotypic age, while animal-based food consumption correlated with adverse aging effects. MVMR revealed the benefits of carbohydrate intake on aging, reducing phenotypic age ({beta}C=C-0.0025; 95% CI=[-0.0047, -0.0003]; p = 0.026) and increasing whole-brain grey matter volume ({beta}C=C0.0262; 95% CI=[0.007, 0.046]; p = 0.008). Overall, our study underscores diets significant role in biological aging, highlighting the potential advantages of a carbohydrate-rich diet in promoting healthy aging.