Trace elements in fingernails of healthy Chinese centenarians

Trace element concentrations in body tissues of healthy centenarians have not been widely analyzed, yet they can be used as reference data leading to improved assessment of the aging process and monitoring of the micronutrient status of this age group. The present study sought to assess trace element concentrations and behaviors in the fingernails of healthy Chinese centenarians. The effects of gender on element concentrations, which also play an important role in determining the lifespan, were also investigated. Trace elements (Ba, Cd, Co, Cr, Cu, Fe, Li, Mn, Mo, Ni, Pb, Se, Sr, and Zn) in the fingernails of 78 healthy Chinese centenarians were determined by inductively coupled plasma mass spectrometry. The overall reference values obtained in milligram per kilogram are as follows: Ba, 5.10; Cd, 0.031; Co, 0.101; Cr, 0.82; Cu, 3.71; Fe, 154.35; Li, 0.31; Mn, 3.09; Mo, 0.040; Ni, 0.95; Pb, 1.86; Se, 0.44; Sr, 6.20; and Zn, 147.96. Data analysis showed that only Cr and Se concentrations show a normal distribution, and no significant difference between male and female groups was found for any element except Cr. Result also revealed that sufficient Se, Co, and Zn as well as lower or lack of exposure to Cr contribute positively to the lifespan of centenarians. The results suggest that regulating in vivo contents of trace elements, especially Se, Co, and Zn, is reasonable to intervene with geriatric diseases.