- Pregnant women who smoke do not just harm the health of their baby, they can actually harm their DNA child, according to a new study. The discovery may explain why children of smokers continue to suffer from health complications later in life.
Babies born to smoking mothers tend to be smaller, have impaired lung function, and have a higher incidence of birth defects. Even in adulthood, these people have health and behavioral problems, with those born to smokers are more likely to have asthma, nicotine addiction, and addiction. "We have a limited understanding of the biological mechanisms for such effects," write Christina Markunas genetic epidemiologist and perinatal epidemiologist Allen Wilcox of the National Institute of Environmental Health Sciences in Research Triangle Park, North Carolina, in an e- email joined science . One possibility is the so-called epigenetic changes. Various triggers-ranging environmental stress diet can chemically modify DNA, turning genes on or off.
the new study is one of the largest of its kind to determine whether maternal smoking can cause such changes researchers analyzed blood collected from 889 infants just after delivery. about a third were born mothers who reported smoking during the first quarter. the team examined the chemical labels called methyl groups-just one of several types of epigenetic DNA modifications.
The results of the study were surprising. Children born to smokers showed epigenetic changes in their DNA that are not present in children of non-smokers, the group reported online ahead of print in Environmental Health Perspectives . Compared to children of non-smoking mothers, babies born to smokers had alterations in more than 100 gene regions. Among the affected genes were those related to the development of the fetus, nicotine addiction, and the ability to quit smoking.
The work provides some of the evidence to date that maternal behaviors can modulate fetal DNA during pregnancy. In addition, the findings are supported by previous research indicating maternal smoking may alter the DNA of the newborn, said Andrea Baccarelli, director of environmental epigenetics laboratory at Harvard University. The results of this large-scale survey are consistent with the results of earlier, smaller studies and research directly examine the effects of chemicals on cells of cigarettes, he noted. "It is a wonderful example of the convergence between studies [lab-based] toxicological and human studies."
However, several questions remain. On the one hand, epigenetic changes detected in newborns can not stay. "There is no way of knowing whether these epigenetic changes are fleeting and part of the regular cell development or a more permanent and truly smoke exposure of results," says Valerie behavior geneticist Knopik Rhode Island Hospital in Providence and Alpert Medical School of Brown University.
Although more research is needed to understand the implications of DNA changes observed in infants, the results open the door to other questions about the health of children. "If maternal smoking may alter the methylation pattern of the DNA of newborns, other environmental exposures to chemicals, such as those found in the air, our homes and food during pregnancy can also have epigenetic effects, "Wilcox Markunas and write. "We have only scratched the surface of how exposure during pregnancy may affect the baby."
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