Association Between Dietary Factors, Physical Activity and Markers of Immunological Aging

Abstract

Background Immunological age describes the functional and phenotypic state of a person’s immune system and often differs significantly from their actual chronological age. This can manifest in susceptibility to infections and the development of chronic diseases. This process, known as immunosenescence, does not merely describe a decline in the function of the immune system. The composition of immune cells also changes, and persistent inflammation, known as inflammaging, plays a decisive role. This study investigates the influence of dietary habits and physical activity on immune markers. It is hypothesised that a higher intake of immune-relevant macronutrients and micronutrients, combined with increased physical activity, leads to a more favourable immunological phenotype. Methods The study was conducted in Graz in 2024 and included a total of 120 healthy adults. Participants aged 40 and under (n=100) formed the comparison group and were further divided into three groups depending on their immunological phenotypes (young, middle-aged and old immune systems) based on laboratory parameters. Participants aged 50 and over (n=20) formed the control group for the laboratory values. Dietary habits were recorded over four days using food diaries. Physical activity was assessed using specialised questionnaires. Subsequently, nutrient intake and physical activity were compared with markers of immunological age. Results Of the initial 120 participants, the results for 87 were included in the final analysis. Statistically significant differences between the groups were observed in the daily intake of total energy, protein, zinc, selenium and niacin. Participants with a phenotypically younger immune system consumed less of these nutrients overall than participants with an older immune phenotype. Discussion Although the differences were statistically significant, all participants consumed nutrient amounts within the recommended daily intake. Participants with a phenotypically older immune system showed a higher overall energy intake, suggesting that a general reduction in food intake in the group with a younger immune system, rather than the composition of the diet and nutrient density, may underlie the observed associations.

Date of Award	2026
Original language	English
Awarding Institution	Medical University Graz
Supervisor	Sonja Lackner (Supervisor)