Carbon, Nitrogen, And Sulfur Elemental And Isotopic Variations In Mouse Hair And Bone Collagen During Short-Term Graded Calorie Restriction

This study investigated the impact of graded calorie restriction (CR) on the elemental content and stable isotope ratios in mouse bone collagen and hair keratin over 84 days. As CR increased (10-40%), hair showed decreased δ15N, δ13C, and δ34S values, with δ15N being significantly affected. In contrast, bone collagen exhibited increased δ15N and decreased δ13C values, suggesting intensified mobilization of endogenous proteins and lipids. Additionally, the carbon, nitrogen, and sulfur content in bone collagen decreased with more extensive CR, indicating structural changes in vivo. These findings highlight the complexity of using elemental indicators to assess collagen quality, especially under nutritional stress, which could complicate archaeological studies.