according to a recent Taiwanese study. This latest study of Taiwanese families looked at paternal smoking during the mother’s pregnancy and its effects on immune system genes. The researchers looked for signs of asthma in over 1,600 babies, 756 of which were followed for six years.
Twenty-three per cent of the fathers were smokers, compared to just three per cent of the mothers. Infants with prenatal parental tobacco smoking exposure had a significantly higher risk of asthma by the age of six than those without.
It is already widely known that exposure to tobacco smoke, or any kind of habitual combustible during development harms children, and non-coding epigenetic changes to DNA have been repeatedly found. However little is known about the effects of paternal smoking in the future offspring and possible impacts on epigentic programming. Epigenetics is the study of heritable phenotype changes that do not involve alterations in the DNA sequence itself, but still have noticeable impacts and or traits on the development of whatever given organism.
This recent Taiwanese study revealed how immune genes can predict the level of risk, and found that just like maternal smoking or air pollution, paternal smoking during pregnancy can also program epigenetic modifications, which in turn increase the associated risk of childhood asthma.
“We found that prenatal exposure to paternal tobacco smoking is associated with increased methylation of certain immune genes, which alters how the genetic code is read,” says lead author Dr Wu Chih-Chiang of Po-Jen Hospital in Kaohsiung, Taiwan. “This smoking associated DNA methylation is significantly retained from birth to six years of age, and correlates with development of childhood asthma.”
“Children with prenatal parental tobacco smoking exposure corresponding to more than 20 cigarettes per day had a significantly higher risk of developing asthma than those with fewer than 20 cigarettes per day,” reports senior author Dr Kuender Yang of Mackay Children’s Hospital in Taipei.
The higher the parental tobacco smoking exposure dose, the higher the level of methylation of LMO2, IL10 and GSTM1 which are the genes known to have key roles in immune function. The higher the methylation level, the higher the associated risk of asthma.
“It remains to be determined whether the DNA methylation associated with parental tobacco smoking originated from tobacco smoke exposure in utero, from preconception changes to the father’s sperm, or if there is an alternative explanation,” Dr Wu says.
Unfortunately currently there is no cure for asthma, a condition in which the airways narrow and swell and produce extra mucous. It makes breathing difficult and triggers coughing, wheezing and shortness of breath in most people who suffer from it.
Does this mean that there may be a similar finding with eLiquids and vaping? Perhaps in the future we will have such studies available, but for now this study offers some unique insights on the roles of epigentics and how they play out in the development of children.