(RxWiki News) Secondhand smoke can be harmful to children. But it may also harm children before they're even born.
New research suggested that fathers who smoked were more likely to have children with non-allergic asthma.
Non-allergic asthma is asthma without hay fever, an allergy caused by pollen or dust. Asthma is a condition marked by breathing problems, often caused by allergies.
"Seek advice on quitting smoking from a medical professional."
The research was led by Cecilie Svanes, MD, PhD, a professor at the Centre for International Health at the University of Bergen in Norway. She presented her findings Sept. 8 at the European Respiratory Society’s International Congress in Munich, Germany.
Past animal studies have suggested that fathers smoking before conception could influence asthma in their offspring.
The study authors assessed lifetime smoking in 13,499 people. They also surveyed 26,945 offspring, aged 2 to 51 years, for asthma and hay fever.
Among the children of smokers, 3.6 percent had allergic hay fever, and 7.5 percent had non-allergic asthma.
Non-allergic asthma was found to be more common among children whose fathers starting smoking before 15 years of age, and in those whose fathers smoked for the longest time. This was true even if the father quit smoking five years before conceiving the child.
The mother’s smoking habits were not associated with asthma in the children.
"This study is important as it is the first study looking at how a father’s smoking habit pre-conception can affect the respiratory health of his children," Dr. Svanes said in a press release. "Given these results, we can presume that exposure to any type of air pollution, from occupational exposures to chemical exposures, could also have an effect.”
According to Mark Millard, MD, Medical Director of the Martha Foster Lung Care Center at Baylor University Medical Center at Dallas, "This is a bit of a surprise, and the authors speculate that smoking may have some lasting effect upon sperm formation. But the real question is how much of an effect, and do the numbers prove smoking is the cause of this association?
"The odds ratios are also a bit low, even if statistically significant. Crunching numbers can sometimes lead to unusual conclusions which can form the substance of later studies to verify an observation. More research needs to be done here," Dr. Millard explained.
"It is important to recognize that these numbers come from large databases, which means it takes thousands of individuals to show there may be an association, but this doesn’t mean causation," he said. "For example, I associate with lots of smokers (as a lung doctor), but that doesn’t mean I smoke myself or will suffer a smoking-related disease."
Dr. Svanes and team have not yet published their findings. Research presented at conferences has not necessarily been peer-reviewed.
The authors disclosed no funding sources or conflicts of interest.