Could the consequences of tobacco be transmitted through the generations? In any case, this is what a new Australian study suggests. Children whose grandparents were smokers may be at higher risk of developing asthma.
- In France, 4 million people are affected by asthma.
- Asthma results in a chronic inflammation of the bronchial tubes which can cause attacks of shortness of breath, coughing, wheezing or permanent difficulty breathing.
Asthma is manifested by episodes of difficulty breathing. The frequency and severity of seizures vary for each patient. Breathing is usually normal between seizures. A recent study by the European Respiratory Journal suggested that children are more likely to develop this chronic disease if their fathers were exposed to passive smoking during childhood.
The consequences of passive smoking across generations
This work was led by Jiacheng Liu and Doctor Dinh Bui of the University of Melbourne (Australia). The two scientists analyzed information from the Tasmanian Longitudinal Health Study (TAHS) which began in 1968.
Led by Professor Shyamali Dharmage, this research observed 1,689 children living in Tasmania, their fathers and paternal grandparents. The team assessed the proportion of children who had developed asthma from the age of 7 whose fathers had grown up with parents who smoked when they were under 15. It was also mentioned whether the children’s fathers were smokers or former smokers.
“We found that the risk of non-allergic asthma in a child increases by 59% if their father was exposed to passive smoking during childhood compared to a child whose father was not exposed. The risk was even higher, namely 72%, if the fathers had been exposed to second-hand smoke and had become smokers themselves”, explained Jiacheng Liu.
Hypotheses studied to explain the transmission of asthma
According to their findings, a child’s risk of asthma is further increased when his father was exposed to passive smoking and later became a smoker. “Our results show how the harm caused by smoking can impact not only smokers, but also their children and grandchildren. For men who were exposed to passive smoking as children, our study suggests that they can further reduce the risk of asthma transmission, if they avoid smoking”, explained Doctor Dinh Bui.
But how can a grandson of a smoker develop asthma if he has not been exposed to tobacco smoke? So far, researchers have only speculated. According to them, epigenetic changes could be responsible for the onset of asthma. These phenomena correspond to factors in our environment (tobacco, pollution) which interact with genes to modify their expression. “It’s possible that tobacco smoke creates epigenetic changes in cells that will produce sperm when boys grow up. These changes can then be passed on to their children.” the scientists said.
