In a new study, researchers looked at epigenetic markers to investigate how teenage smoking among fathers affects the health of offspring.
The article, published in the journal Clinical Epigenetics, is the first human study to reveal biological links between fathers' early teenage smoking and their children. In the study, the researchers argue that this smoking can damage the genes of future children and thus increase the risk of developing asthma, obesity and low lung function.
Could affect future generations
Researchers at the University of Bergen and the University of Southampton have examined epigenetic profiles in 875 people aged 7-50 and the smoking habits of their fathers. The researchers found epigenetic changes at 19 sites when they mapped 14 genes in children of fathers who smoked before the age of 15. These changes in the way DNA is packed in cells (so-called methylation) regulate gene expression and are associated with asthma, obesity and breathing difficulties.
The new findings may also be important from a public health perspective:
«Our studies in the large international RHINESSA, RHINE and ECRHS studies have shown that the health of future generations depends on the actions and decisions taken by young people today, long before they become parents. This applies especially to boys in early puberty or mothers and grandmothers, before pregnancy and during pregnancy. It is really exciting that we have now managed to identify a mechanism that explains our observations in the cohorts», says Professor Cecilie Svanes at the University of Bergen.
Found unique links
In the study, changes in epigenetic markers were much more visible in children whose fathers started smoking during puberty.
«Early puberty may represent a critical window for physiological changes in boys. This is when the stem cells are established that will make sperm for the rest of their lives», says co-author Dr. Negusse Kitaba, research fellow at the University of Southampton.
The research group also compared epigenetic markers linked to fathers' smoking before conception in people who smoked themselves, and those whose mothers smoked before conception.
«What is interesting is that 16 of the 19 markers associated with father's teenage smoking have not previously been linked to personal or mother's smoking, says Toril Mørkve Knudsen from the University of Bergen, who is one of the first authors of the study.
«This may actually indicate that the new methylation signals we have found may be specific epigenetic changes that are unique to fathers' smoking exposure in early puberty», says Knudsen.
Nicotine might harm
Although the number of young people who smoke has gone down significantly since the 50s and 60s, researchers are concerned about the use of electronic cigarettes among young people.
«Some animal studies suggest that nicotine may be the substance in cigarette smoke that drives epigenetic changes in offspring», says Professor John Holloway at the University of Southampton.
«It is therefore worrying that teenagers today, especially teenage boys, are exposed to very high levels of nicotine through vaping», says Holloway.
The article "Fathers' preconception smoking and offspring DNA methylation" has been published in the journal Clinical Epigenetics and can be read here: