Facebook has many uses, but scientific research is not usually considered to be one of them. However, this social networking site, immensely popular among young people, helped Canadian researchers track children who were part of a study five years ago. The study was on nicotine dependence among school children. As they followed the habit once again among the teenagers, the scientists gained two valuable insights on smoking and adolescents — first, that smoking does not make girls thin and, second, that it makes boys shorter. Both findings contradicted common perceptions about smoking in North America, and probably in the rest of the world as well.
Researchers have been looking at smoking in children and adolescents for some time now, because tobacco addiction generally starts somewhere in high school or early university life. By global standards, the problem is not very serious in North America, which has seen a decline in smoking over the years. In fact, the World Health Organization lists India as one of the nations with a high prevalence of smoking among the young, along with Central and Eastern Europe and some Pacific Islands. However, smoking does start early sometimes in North America, as in India and other parts of the world. And misconceptions about smoking are often a strong motivation to start tobacco use.
As a young girl, Jennifer ’ Loughlin had heard about smoking and weight control early in life. “Smoking will make you thin,” she was told by many while she was growing up. Now as an epidemiologist and biostatistician at the University of Montreal, she has been studying the natural history of nicotine dependence. A few years ago, she had found compelling evidence for a genetic role in the development of nicotine dependence among teenagers. Now her study, done with colleagues in other Canadian institutions, debunks a popular myth: that smoking is good for weight control among girls.
As she had known always, girls in North America often cite this as a reason to start smoking. This finding should thus be a strong deterrent, but what the scientists found among boys was even more interesting. Boys who smoked regularly grew up to be an inch shorter. Since growing tall is one of the ambitions of adolescent boys, this finding should be an even stronger deterrent to smoking among boys. Says ’ Loughlin: “Boys now may see smoking as a bad choice if they want to grow tall.”
Smoking among children and adolescents has received considerable attention among scientists of various disciplines. Most of these studies did not provide any conclusive evidence of why adolescents smoked or how smoking affects them. For example, a part of the Global Youth Tobacco Survey in Punjab in 2003 got conflicting results regarding motivations. The participants said that boys or girls who smoke have more friends. But they also said that those who smoke are less attractive.
Three years ago, scientists at the Yale University studied all the research literature on smoking and weight concerns among teenagers. They found that a significant number of teenage girls believed smoking was a way of weight control, but they did not find any relationship in practice. On the other hand, heavier boys reduced their body mass index when they smoked. Girls who smoked more cigarettes were more concerned about gaining weight after they quit, which provided a strong motivation to continue smoking.
’ Loughlin had started studying smoking in children in 1999. She had funding from the Canadian Cancer Society. She followed a cohort of students in high school for five years. “Children in North America generally start smoking at the age of 12,” she says. “Some start even at eight.” She had then found a possible genetic link, a predisposition that makes some pick up the habit when exposed to it.
A few years later, she wanted to follow these students again. There were 1,300 of them, and many of them had gone away from where they originally lived. But the scientists managed to trace every one of them. “We used Facebook heavily to trace the students,” says ’ Loughlin. She had a grant of $650 million, again from the Canadian Cancer Society. The results of the study provided compelling evidence of smoking and height and weight among children aged between 12 and 17. Girls do not shed weight when they smoked. Boys shed height when they did.
While common sense says that smoking should not cause any difference in weight, the decrease in height is more intriguing. The study found that boys who smoked 10 cigarettes a day from the age 12 to 17 would be an inch shorter than a boy who did not smoke. This was not true of girls, probably because boys attain full height a few years later than girls do. Why does this happen? There is no clear answer, but we can hazard a guess. Maybe nicotine deprives the body of oxygen. Maybe it somehow affects the growth hormones. Whatever the reason is, the message is loud and clear.
Sources: The Telegraph (Kolkata,India)