Exposure to tobacco smoke as a baby causes the body to age faster

BARCELONA, Spain — Exposure to tobacco smoke during pregnancy and as an infant can accelerate your biological clock, a new study warns. Researchers with the Barcelona Institute for Global Health (ISGlobal) have discovered that harmful environmental factors like secondhand smoke can alter the epigenetic age of children.

Previous studies show that environmental factors during pregnancy and early childhood can significantly change a child’s metabolism and physiology. Some of these changes can even be irreversible. While many of these changes affect a person’s health and risk of disease later in life, they can also impact the rate at which someone ages much sooner.

On a cellular level, the aging process starts at the beginning of life and scientists are able to measure it using epigenetic clocks. These clocks use the level of DNA methylation in certain areas of your genes to determine the biological age of a person. This result can be very similar or very different from a person’s chronological age (their birthday).

“The epigenetic clock allows us to assess whether someone’s biological age is older or younger than his or her chronological age,” explains ISGlobal researcher and study author Mariona Bustamante, in a media release.

Some toxins affect a child’s aging more than others

Researchers examined early life exposure to tobacco smoke and other environmental factors among 83 prenatal infants and 103 babies. They also measured the epigenetic age of 1,173 children between ages six and 11 from the Human Early Life Exposome (HELIX) project.

Their findings reveal exposure to maternal tobacco smoke during pregnancy shows a clear link to accelerated epigenetic aging. After birth, the team also discovered a link between two other kinds of environmental exposures — parental smoking and indoor levels of black carbon. The latter is an air pollutant resulting from the incomplete combustion of fuels.

Surprisingly, the study finds two other factors that actually appear to slow biological aging — the organic pesticide DMDTP and a persistent organic pollutant called polychlorinated biphenyl-138.

“Further 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,” adds Bustamante.

The study appears in the journal Environment International.