If teenage boys smoke, they risk affecting the genes of their future children
New research shows that the future children of boys who smoke in their early teens risk being predisposed to developing asthma, obesity and low lung capacity.
Cigarettes and mothers-to-be have long been recognised as a bad combination. But now a new study shows that boys in early puberty may harm their future children by smoking.
Researchers from Aarhus University, the University of Southampton and the University of Bergen have studied the epigenetic profiles of 875 people between the ages of 7 and 50 from Denmark, Estonia, Norway, Spain and Australia, and they have recorded the fathers' smoking behaviour.
Epigenetics is the part of genetics that deals with how the information contained in our genes is expressed and translated.
The study shows that when boys smoke in their early teens, they risk affecting the genes of their future children, increasing the risk of the children developing asthma, obesity and low lung function.
The research has just been published in the scientific journal Clinical Epigenetics - and it reveals as many as 19 epigenetic changes in 14 genes in the children of fathers who smoked before the age of 15.
Worst if boys start smoking early
Those whose fathers had smoked in their early teens had epigenetic markers associated with asthma, obesity and low lung function. The changes were much more pronounced in people whose fathers started smoking during puberty than in those whose fathers started smoking at a later stage before conception.
"The study shows that the health of future generations depends on the decisions made by young people today – long before they become parents," says Professor Vivi Schlünssen from the Department of Public Health at Aarhus University, who is one of the authors behind the study.
"The study is the first to show how teenage boys' smoking affects the biological mechanism that can transfer harmful epigenetic changes to future children. This suggests that early puberty represents a critical window of physiological changes in boys, when they establish the cells that will produce sperm for the rest of their lives," says Vivi Schlünssen.
Nicotine can be crucial
The researchers also compared epigenetic markers where the father, mother or the offspring have smoked.
"Interestingly, we discovered that 16 of the 19 markers associated with father’s teenage smoking had not previously been associated with the mother's smoking or the offspring's own smoking," says Postdoc Gerd Toril Mørkve Knudsen from the University of Bergen, who is a co-author of the study.
It is also is worrying that the use of e-cigarettes is growing in several countries, including in Denmark.
"Some animal experiments suggest that nicotine may be the crucial substance in cigarette smoke that drives the epigenetic changes in the next generation – so it is deeply worrying that teenagers today, especially teenage boys, are exposed to very high levels of nicotine through e-cigarettes," says Gerd Toril Mørkve Knudsen.
Professor John Holloway from the University of Southampton, who is also behind the study, says that data in the study comes from people whose fathers smoked as teenagers in the ‘60s and ‘70s, when smoking tobacco was much more common.
"We can't say with certainty that e-cigarettes will have similar effects across generations, but we shouldn't let time tell what impact it may have in the longer term. We have to act now,” he says.
"The study shows that failure to address young teenagers' exposure to substances in cigarettes and e-cigarettes today may harm the health of future generations."
The research results - more information
- The study is a multicentre epigenome-wide association study (EWAS) in the RHINESSA cohort of 875 people aged 7-50 years, with information about their fathers' smoking habits before and after puberty.
- The study was initiated by Professor Cecilie Svanes from the University of Bergen and John Holloway from the University of Southampton with data from Denmark, Norway, Australia, Estonia and Spain
- It was partly funded by EPHOR (Work life exposome, lung function and COPD), Horizon 2020, call SCi-BHC-2018-2020).
- Read the scientific article: Fathers' preconception smoking and offspring DNA methylation - PubMed (nih.gov)
Contact
Professor Vivi Schlünssen
Aarhus University, Department of Public Health
Mobile: +4528992499
Email: vs@ph.au.dk