Exposure to environmental factors during pregnancy can modify our metabolism and physiology, thereby analyzing our health status later in life.
It can also hasten the process of biological ageing, which is linked to various metabolic, cardiovascular or neurodegenerative diseases.
Epigenetic clocks use the levels of DNA methylation in to infer biological aging of a person.
“The epigenetic clock allows us to assess whether someone’s biological age is older or younger than his or her chronological age,” explains Mariona Bustamante, ISGlobal researcher and last author of the study.
Previously, various studies shown the link between an acceleration in epigenetic ageing and environmental exposures, but most were performed in adults and focusing on single exposures.
In the current study, the team led by Bustamante investigated for the link between the early-life exposome and the epigenetic age of 1,173 children between 6 and 11 years of age from the Human Early Life Exposome (HELIX) project, based on six birth cohorts in six European countries, including Spain, and coordinated by ISGlobal researcher Martine Vrijheid.
Findings include that the exposure to maternal tobacco smoke during pregnancy was associated with an acceleration in epigenetic ageing.
Also, there is a link between parental smoking and indoors levels of black carbon.
Two other variables were linked to a slowing in biological ageing: the organic pesticide DMDTP and a persistent organic pollutant (polychlorinated biphenyl-138).
“More research is needed to explain these results, but the former could be due to a higher intake of fruits and vegetables while the latter could be explained by its correlation with body mass index,” says Paula de Prado-Bert, first author of the study.
“The positive association between epigenetic age acceleration and exposure to tobacco smoke during pregnancy and early childhood go in line with previous results obtained in the adult population,” says Bustamante. The epigenetic modifications could affect pathways involved in inflammation, toxin elimination, and cell cycle, with a subsequent impact on health.
These associations do not prove a causality, but this and future early life exposome studies will help guide health policies to reduce certain environmental exposures and promote a “healthy ageing” from early life stages.