Fathers' Smoking May Affect Children and Grandchildren

When it comes to children’s exposure to the effects of smoking through their parents, people think that this can only happen through one of two ways: By being exposed to secondhand smoke from being around a smoking parent or by having a mother who smoked during pregnancy.

But a new study exploring the effects of nicotine on the offspring of male mice suggests that the potential generational effects of smoking can happen in more ways than previously thought.

The study

A team of researchers from Florida State University in Tallahassee sought to determine whether males’ exposure to nicotine from cigarette smoke could have negative effects on their descendants. Their findings were published in the PLOS Biology journal.

Previous studies have been able to show a link between cognitive and behavioural problems in children (such as ADHD) and a mother’s exposure to nicotine and other components in cigarette smoke, but determining whether a father’s smoking can have a similar impact has been more challenging. This is because it has been hard to establish whether the children of smoking fathers suffered these effects because of their genetic predisposition to them or because of their direct exposure to secondhand smoke from their fathers.

The researchers overcame these challenges by exposing a group of male mice to low-doses of nicotine in their drinking water. The mice used in this experiment were in the sperm-producing phase of their lives and were later bred with female mice who were never exposed to nicotine. While the male mice remained behaviourally normal, their female and male pups showed signs of attention deficit and hyperactivity as well as other cognitive issues.

Interestingly, when the female pups matured and bred with male mice who have never been exposed to nicotine, their male offspring displayed fewer cognitive and behavioural abnormalities than the offspring of the male pups.

When the researchers analysed the sperm cells of the original nicotine-exposed mice, they found that regions of several genes have been altered by an external factor. One of the genes found to be affected is the Dopamine D2 gene which is considered to be essential for learning and brain development. The researchers believe that the changes in this gene are likely responsible for the cognitive and behavioural defects in the descendant mice.

Why does this matter?

Although more research is needed to determine if nicotine and smoking have these effects on human males, both have been known to alter gene expression in humans, similar to what was seen in the mice.

Pradeep Bhide, one of the researchers involved in the study, says that this type of research is important on a public health level because men are more likely to smoke than women and that it’s essential to know the effects this can have on their children.

So now we have it: It’s down to both parents to put down their lighters for the sake of their future kids’ health.

By Tesneem Ayoub