Aging is a complex biological process characterized by a gradual decline in physiological functions and an increased susceptibility to develop various diseases. As the world's population ages, there is growing interest in identifying dietary strategies that can support healthy aging and mitigate age-related pathologies.

Minerals, such as calcium (Ca), magnesium (Mg), iron (Fe), copper (Cu), zinc (Zn), selenium (Se), iodine (I), and manganese (Mn), play a crucial role in various biological processes and are essential for maintaining optimal health during aging [1], [2], [3], [4], [5], [6], [7], [8], [9]. Particular attention should be given to Zn and Se, as they exert vital functions in the immune, and antioxidant system [10], [11]. Furthermore, both have been demonstrated to decline in serum with increasing age [12]. For both elements, scientific research also endeavors to explore biomarkers. For zinc, there is an increasing focus on free zinc (fZn) [13], which reflects the fraction of metabolically active zinc. The concentration of selenoprotein P (SelenoP) in serum is largely established as a biomarker for selenium status [14], [15], [16], [17]. While serum Mn also shows a negative association with aging, other minerals, such as Fe, Cu, and I, were found to increase in serum with advancing age [12]. Therefore, they also become intriguing targets for research regarding healthy aging and necessitate comprehensive monitoring to obtain a comprehensive overview of the characteristics of mineral status.

Furthermore, the aging process has been linked to deteriorating inflammation status and subsequent adverse health outcomes [18], [19]. Targeted dietary interventions focusing on providing adequate nutrients have been shown to improve inflammation status in the aging population [20]. Some minerals, such as Zn [21], Se [22], Mn [23], Mg [24], Cu [25], and Fe [26] also appear to be associated with inflammation markers like IL-6 and CRP. Accordingly, we aimed to investigate whether changes in mineral status are accompanied by alterations of the inflammatory markers.

In the context of healthy aging, the NutriAct study, a randomized controlled dietary intervention trial (RCT), was designed to investigate the impact of dietary patterns on the development of age-related diseases [27]. Hence, the main objective of the NutriAct study was to develop a dietary pattern that enables the prevention of age-related diseases, in order to prepare middle-aged people for the late old age. The focus of this article will be on the assessment of the mineral status of the participants within the NutriAct study project throughout a two-year period. By incorporating regular consumption of nuts, various legumes, fish, whole grains, and dairy products, which are excellent food sources for minerals, changes in mineral status may occur alongside the primary endpoints investigated within the NutriAct study. However, introducing these dietary patterns, which additionally emphasize intake of protein from plant sources and high fiber intake, could also contribute to negative changes in mineral status. The significance of dietary patterns for human health underscores the importance of investigating how various dietary approaches can exert long-term effects on mineral status. This exploration aims to enhance our understanding of the intricate relationship between dietary choices and mineral levels over an extended period. Previous research has explored the effects of a plant-based diet on circulating mineral concentrations in humans [16], [28]. However, these studies either focused on short-term effects [16], or compared omnivorous and vegan dietary patterns at baseline [28]. Our investigations are directed towards a comprehensive study of minerals as biomarkers. Hence, the aim of this work was to determine long-term effects of different interventional dietary patterns on the mineral status and related inflammatory markers of a middle-aged German population. Through comprehensive characterization of mineral status over a two-year period, time-, intervention-, and gender-specific differences will be examined.