Results of the Melbourne University study were published in British medical journal Thorax.
Photo: 123rf.com
Smoking around your children may hurt the lung health of your grandchildren, according to Australian research.
The Melbourne University study, published in British medical journal Thorax has found the risk is worse, if that generation is also exposed to passive smoking.
Lead researcher Jiancheng Liu said several factors increased the risk of poor lung function and subsequent COPD (chronic obstructive pulmonary disease), but attention was now beginning to focus on “the potential role of intergenerational factors”.
The research involved 8022 child participants from the Tasmanian Longitudinal Health Study, which started in 1968, who had check-ups at ages seven, 13, 18, 43, 50 and 53.
Key findings:
More than two-thirds of fathers (nearly 69 percent) and more than half the children (56.5 percent) were exposed to passive smoking in childhood
Around half of the children (49 percent) were smokers themselves by middle age, and just over 5% of them had developed COPD
Father’s passive smoke exposure as a child associated with 56 percent higher odds of below-average lung function in his children over their lifespan, and double the rate of early decline in respiratory capacity
Exposure to passive smoking for boys also associated with double the risk of COPD by the age of 53 in their children, although this was no longer statistically significant, after adjusting for other factors
Earlier research by the same team in 2022 found passive smoking during a father’s childhood could be linked to a heightened risk of asthma in his own children by the age of seven.
Liu said more research was needed to work out the actual epigenetic factor at work, but there were key differences for boys and girls.
Other studies had shown unborn baby girls’ exposure to smoking put their future children’s lung function at risk, he said.
“Men begin spermatogenesis [sperm production] at puberty, but in females, all the oocytes [immature eggs] are already present during their own intrauterine life [while they are in the womb], so the exposure and outcomes could be different for future mothers and future fathers,” Liu said.
However, the good news was that people could still make a positive difference for their children.
“If these children are not exposed to passive smoking in their own childhood, the influence from their fathers is decreased, so we can say, if the father has already been exposed to passive smoke, he can choose not to smoke himself, so his children have decreased risk.”
More evidence that smoking has ‘long tail’
Respiratory specialist Professor Bob Hancox said the findings were “interesting”, but should be treated with caution, because they did not show “cause”, just association.
“I’m not completely convinced yet that this is all epigenetic, because this is the first study and it’s possible this is confounded by some other mechanisms.
“Even if that’s the case, it’s still suggesting that smoking has a long tail.”
Hancox, who is medical director of the Asthma and Respiratory Foundation, said COPD was not usually diagnosed before middle age, but its origins began much earlier.
“By the time we see it, people may have been losing their lung function for many years, before they get symptoms and it becomes apparent,” he said. “If people have impaired lung function through childhood, they may never reach their ideal peak lung function at the age of 20.
“Even though they’re fine when they’re 20, they’re more likely to develop COPD as they age.”
Action for Smokefree 2025 (ASH) director Ben Youdan said the key message remained that children and young people should not be exposed to smoking.
“What it comes down to is the best thing you can possibly do for your kids is for them to be in a smokefree environment and for parents who are currently smoking to stop.”
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