Accelerated Biological Aging Associated with Exposure to Tobacco Smoke Early in Life: A Study

Barcelona: A new study has shown that exposure to tobacco smoke early in life is associated with accelerated biological aging. The results of the study were published in the journal ‘Environment International’. Accelerated biological aging is associated with exposure to tobacco smoke during pregnancy and infancy, as well as indoor exposure to carbon black. These are the conclusions of an analysis carried out by the Barcelona Institute for Global Health (ISGlobal), an institution supported by the “la Caixa” Foundation, the first to assess the associations between a large number of early environmental exposures and epigenetic age at children. Exposure to environmental factors during pregnancy and infancy can dramatically – and sometimes irreversibly – alter our metabolism and physiology, thereby determining our state of health later in life. It can also speed up the biological aging process, which has been linked to a higher risk of metabolic, cardiovascular, or neurodegenerative diseases. At the cellular level, aging is an ongoing process that begins early in life, and can be measured using epigenetic clocks. Epigenetic clocks use DNA methylation levels in certain regions of the genome to infer a person’s biological aging.

“The epigenetic clock allows us to assess whether a person’s biological age is older or younger than their chronological age,” said Mariona Bustamante, ISGlobal researcher and final author of the study.

Several studies have shown an association between the acceleration of epigenetic aging and certain environmental exposures, but most have been carried out in adults and have focused on single exposures. In this study, the team led by Bustamante investigated for the first time the association between the exposome in early life (83 prenatal exposures and 103 in infancy) and the epigenetic age of 1,173 children between 6 and 11 years from early human childhood. Life Exposome Project (HELIX), based on six birth cohorts in six European countries, including Spain, and coordinated by ISGlobal researcher Martine Vrijheid.

After selecting the best-fit epigenetic clock for the study and adjusting multiple factors, the research team found that exposure to maternal tobacco smoke during pregnancy was associated with accelerated epigenetic aging. Regarding the postnatal exposome, analysis showed an association with two exposures: parental smoking and indoor levels of carbon black, an air pollutant that results from incomplete combustion of fuels (and is indirectly measured by the absorbance of particles or PMabs). Curiously, two other variables were associated with a slowing down of biological aging: the organic pesticide DMDTP and a persistent organic pollutant (polychlorobiphenyl-138).

“More research is needed to explain these results, but the former could be due to higher consumption of fruits and vegetables while the latter could be explained by its correlation with body mass index,” said Paula de Prado-Bert, first author of the study. to study.

“The positive association between epigenetic acceleration of age and exposure to tobacco smoke during pregnancy and infancy is consistent with previous results obtained in the adult population,” Bustamante said.

Epigenetic changes could affect pathways involved in inflammation, toxin elimination and the cell cycle, with subsequent impact on health.

Admittedly, these associations do not prove causality, but this study and future studies on exposomes at the beginning of life will make it possible to orient health policies to reduce certain environmental exposures and promote “healthy aging” from the early stages. of life.