Association of dietary selenium intake with telomere length in middle-aged and older adults

Background: Growing evidence suggested that lifestyle factors including dietary habits may influence the telomere length which is a reliable marker of biological aging and predictor for chronic diseases. However, the role of dietary selenium intake in telomere length maintenance is rarely examined. Objective: We aimed to test the relationship between dietary selenium intake and telomere length among middle-aged and older adults in America. Methods: A total of 3194 United States adults older than 45 years old were extracted from the National Health and Nutrition Examination Survey (NHANES) in 1999-2000 and 2001-2002. Leukocyte telomere length was measured using the quantitative real-time polymerase chain reaction (qPCR). Dietary selenium intake was assessed by a trained interviewer using 24-h dietary recall method. Generalized linear models were performed to evaluate the association of dietary selenium intake with telomere length. The restricted cubic spline analysis was used to further explore the nonlinear dose-response relationship between dietary selenium intake and telomere length. Results: After adjusting potential confounders, every 20 jig increase in dietary selenium intake was associated with 0.42% (95% CI: 0.02%, 0.82%) longer telomere length in all participants. In the subgroup analyses, dietary selenium intake was related to longer telomere length in females (Percentage change: 0.87%; 95% CI: 0.26%, 1.49%) and non-obese participants (Percentage change: 0.53%; 95% CI: 0.04%, 1.02%), but not in males (Percentage change: 0.04%; 95% CI: -0.49%, 0.57%) and obese participants (Percentage change: 0.21%; 95% CI: -0.47%, 0.91%). The restricted cubic spline analysis showed a linear association between dietary selenium intake and telomere length. Conclusions: This study indicated that the increased dietary selenium intake was associated with longer telomere length among middle-aged and older adults in America. These findings require further corroboration from future prospective studies. (C) 2020 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.