Knopf, Bailey A.

Low protein (LP) diets improve metabolic health in rodents and humans. In rodents, LP diets are typically implemented by replacing protein with carbohydrates like sucrose or cornstarch, keeping diets isocaloric. However, humans can choose from many different types of carbohydrate, and how dietary carbohydrate quality - the precise composition of the dietary sugars - impacts the response to dietary protein remains largely unexplored. Here, mice were fed control (21% protein) or LP (7% protein) diets with four different carbohydrate sources: sucrose, a 1:1 glucose/fructose mixture, glucose, or fructose. While LP diets improved metabolic health across all groups in male mice, carbohydrate quality also significantly altered specific health outcomes, with fructose-fed mice having the lowest body weight and adiposity of all control diets. In female mice, responses to LP diets were influenced by carbohydrate quality, with certain sugars inducing a stronger metabolic response to LP diets than previously seen. Finally, in female APP/PS1 mice, a model of Alzheimer's disease, we find that although LP diets reduce A-beta; plaque burden irrespective of carbohydrate type, dietary sugar type does influence spatial memory. Together, these results demonstrate that while dietary protein is a critical determinant of metabolic and neurological health, carbohydrate quality influences these outcomes in a sex-specific manner.

Abstract Geroscience research benefits from interdisciplinary approaches, team science, and collaborations, which collectively facilitate the discovery of aging mechanisms and their translation into tangible, clinical interventions. Since its inception in 2019, the Midwest Aging Consortium (MAC) has provided an engaging platform for aging researchers in the United States’ Midwest to connect, collaborate, and exchange ideas. The Sixth Annual Research Symposium of the MAC held at the Mayo Clinic in Rochester, Minnesota, in April 2025 highlighted the continued impact of the MAC in bringing together aging researchers, including many trainees and early career investigators, into a collaborative environment. This record-setting event featured interdisciplinary research on key aging mechanisms, including lipid metabolism, mitochondrial dysfunction, stress response, cellular senescence, and immune adaptations across organ systems. New therapeutic concepts and clinical trial approaches were presented. Cutting-edge methodologies including single-cell and spatial transcriptomics, metabolomics, and organoid cultures, to dissect aging process in tissue-specific and systemic contexts also were presented. Overall, the MAC symposium underscored the translational potential of geroscience and reinforced the MAC’s mission to accelerate aging research through regional collaborations and innovation.

Abstract As the healthcare burden caused by an increasingly aging population rapidly rises, a pressing need exists for innovative geroscience research that can elucidate aging mechanisms and precipitate the development of therapeutic interventions to support healthy aging. The Fifth Annual Midwest Aging Consortium Aging Research symposium, held from April 28 to 30, 2024, was hosted by The Ohio State University in Columbus, Ohio, and featured presentations from investigators across the Midwestern United States. This report summarizes the research presented at the symposium, whose topics included cellular senescence and the aging brain, metabolism and metabolic interventions, nutrition, redox mechanisms and biomarkers, and stress mechanisms. Abstract presentations and short talks highlighted early-stage and young investigators, whereas 2 keynote presentations anchored the symposium. Overall, this symposium showed the robustness of aging research in the Midwest and underscored the advantages of a collaborative approach to geroscience research.