Higher scores of the Kessler Psychological Distress Scale (K10) are associated with lower serum ergothioneine and higher serum asymmetric dimethyl-L-arginine concentrations in a cohort of middle-aged and older adults

Background: Ergothioneine (ERT) and asymmetric dimethyl-L-arginine (ADMA) have been associated with cognitive decline and dementia in older adults, but their interplay with psychological distress remains unexplored. This study aimed to measure the serum concentrations of ERT and ADMA in a representative sample of older community-dwelling adults and to determine their association with psychological distress. 

Methods: Data on clinical, lifestyle, demographic characteristics, and serum concentrations of ERT and ADMA were collected from a population-based sample of older Australian adults (mean age 65.5 ± 7.5 years) from the Hunter Community Study. Psychological distress was assessed using the self-reported Kessler Psychological Distress Scale (K10). 

Results: In individuals with psychological distress, serum ERT concentrations decreased by 24 %, while ADMA concentrations increased by 6 %. In adjusted analysis, accounting for age and sex, only ERT remained independently associated with psychological distress. For each unit increase in ERT, the odds of experiencing psychological distress decreased by approximately 68 %. 

Conclusion: The trend of decreasing serum ERT concentrations observed in older adults with increasing psychological distress suggests a potential link between this compound and mental health. Given the dietary origin of ERT, its integration offers therapeutic opportunities that warrant investigation in intervention studies.