Mothers who smoke during pregnancy have been linked to asthma in the subsequent third generation.
This is known as a“transgenerational” link because the person in the third generation was never directly exposed to nicotine or smoking.
Previous studies have shown a second generation link between smoking and asthma.
This study is the first to have found a link between pregnant women smoking and lung diseased in the third generation of their children.
“Even though there are multiple causes for childhood asthma, research linking this serious chronic condition to maternal nicotine exposure during pregnancy for up to three generations should give mothers-to-be even more reasons to reconsider smoking,” said Dr Virender K. Rehan, , an LA BioMed lead researcher and the corresponding author of the study.
“Eliminating the use of tobacco during pregnancy could help halt the rise in childhood asthma and ensure healthier children for generations to come.”
Worldwide, approximately 250 million women smoke daily, and the number of people living with asthma is expected to grow by about a third by 2025, reaching approximately 400 million.
In previous studies, the researchers have concluded that the cause of the second generation’s asthma was “epigenetic modification” – an environmental factor causing a genetic change.
Nicotine was affecting both the lung cells and the sex cells in ways that caused the lungs that developed from those cells to develop abnormally, causing asthma. The current study “paves the way for determining the epigenetic mechanisms” behind smoking and the transmission of asthma to future generations, the researchers concluded.
The study was carried out by Los Angeles Biomedical Rsearch Institute at Harbor UCLA Medical Center.
It is published online by the American Journal of Physiology.