Journal Article

Associations of Prenatal Mercury Exposure and PUFA with Telomere Length and mtDNA Copy Number in 7-Year-Old Children in the Seychelles Child Development Nutrition Cohort 2

Myers, Gary J., Shamlaye, Conrad F., Klus, Jonathan K., van Wijngaarden, Edwin, Mulhern, Maria S., Pineda, Daniela, Watson, Gene E., Shroff, Emelyn, Love, Tanzy M., Broberg, Karin, Strain, J. J., Stajnko, Anja, McSorley, Emeir M., Thurston, Sally W., Yeates, Alison J.

2025

Overview

Telomere length (TL) and mitochondrial DNA copy number (mtDNAcn) variations are linked to age-related diseases and are associated with environmental exposure and nutritional status. Limited data, however, exist on the associations with mercury exposure, particularly early in life. We examined the association between prenatal mercury (Hg) exposure and TL and mtDNAcn in 1,145 Seychelles children, characterized by a fish-rich diet. Total mercury (THg) was determined in maternal hair at delivery and cord blood. TL and mtDNAcn were determined relative to a single-copy hemoglobin beta gene in the saliva of 7-y-old children. Linear regression models assessed associations between THg and relative TL (rTL) and relative mtDNAcn (rmtDNAcn) while controlling for maternal and cord serum polyunsaturated fatty acid (PUFA) status and sociodemographic factors. Interactions between THg and child sex, PUFA, and telomerase genotypes were evaluated for rTL and rmtDNAcn. Higher THg concentrations in maternal hair and cord blood were associated with longer rTL [ ; 95% confidence interval (CI): 0.002, 0.016 and ; 95% CI: 0.001, 0.003, respectively], irrespective of sex, PUFA, or telomerase genotypes. Maternal serum n-6 PUFA and n-6/n-3 ratio were associated with shorter [ ; 95% CI: , and ; 95% CI: , , respectively] and PUFA with longer ( ; 95% CI: 0.032, 0.65) rTL. Cord blood n-6 PUFA was associated with longer ( ; 95% CI: 0.050, 0.26) rTL. Further analyses revealed linoleic acid in maternal blood and arachidonic acid in cord blood as the main drivers of the n-6 PUFA associations. No associations were observed for THg and PUFA with rmtDNAcn. Our results indicate that prenatal THg exposure and PUFA status are associated with rTL later in childhood, although not consistently aligned with our initial hypothesis. Subsequent research is needed to confirm this finding, further evaluate the potential confounding of fish intake, and investigate the underlying molecular mechanisms to verify the use of rTL as a true biomarker of THg exposure. https://doi.org/10.1289/EHP14776.

• Publisher: National Institute of Environmental Health Sciences,EHP Publishing
• Subject: Age / Age related diseases / Arachidonic acid / Arbetsmedicin och miljömedicin / Behavior / Bioaccumulation / Biomarkers / Blood / Child / Child development / Children / Children & youth / Cohort Studies / Copy number / Cord blood / Diet / DNA Copy Number Variations / DNA, Mitochondrial - genetics / Environmental Pollutants / Enzymes / Evaluation / Exposure / Fatty Acids, Unsaturated - metabolism / Female / Fetal Blood - chemistry / Fish / Genetic aspects / Genetic testing / Genotypes / Hair / Hair - chemistry / Health aspects / Health Sciences / Hemoglobin / Humans / Hypothesis testing / Hälsovetenskap / Inflammation / Influence / Linoleic acid / Male / Medical and Health Sciences / Medicin och hälsovetenskap / Mercury / Mercury - toxicity / Missing data / Mitochondria / Mitochondrial DNA / Molecular modelling / Nuclear energy / Nutrition / Nutrition research / Nutritional status / Occupational Health and Environmental Health / Oxidative stress / Perfluoroalkyl & polyfluoroalkyl substances / Physiological aspects / Pollutants / Polyunsaturated fatty acids / Pregnancy / Pregnant women / Prenatal experience / Prenatal Exposure Delayed Effects - epidemiology / Regression analysis / Regression models / Saliva / Sex / Seychelles / Statistical analysis / Telomerase / Telomere / Telomeres / Unsaturated fatty acids