14 DAY TRIAL // Age and certain genetic variations could greatly affect one later in life whether or not one becomes a heavy smoker, says a study conducted by the University of Utah in collaboration with researchers of the University of Wisconsin-Madison, again bringing to attention the dangers to which the young are exposed while smoking.
Single nucleotide polymorphism, or SNP for short, is a common genetic variation manifested through the mutation of a single unit of DNA. Linked or inherited SNPs are known as haplotypes. A haplotype associated with the nicotine receptor, the study shows, can determine heavy nicotine dependence in adults who started smoking before the age of 17, while another haplotype can in fact reduce the nicotine dependence in adults, regardless of when they first started smoking on a daily basis.
The study involved 2,827 participants from the states of Utah and Wisconsin, US, as well as from the National Heart, Lung, and Blood Institute's Lung Health Study. Data collected from the participants in the study regarded their level of nicotine dependence, the age at which they started smoking, the number of years since they began to smoke on a daily basis and the number of cigarettes smoked every day, as well as the occurrence of common SNPs.
The results of the study show that people with two copies of high-risk haplotypes who started smoking before the age of 17 are 1.6 to 5 times more likely to become heavy smokers later in life, while people who started smoking on a daily basis at the age of 17 or later as well as those who do not present high-risk haplotypes do not run the risk of developing an addiction. According to previous studies, high-risk haplotypes occur in 38 to 41 percent of the European American population.
"We know that people who begin smoking at a young age are more likely to face severe nicotine dependence later in life. This finding suggests that genetic influences expressed during adolescence contribute to the risk of lifetime addiction severity produced from the early onset of tobacco use," said Ph.D. Robert Weiss of the University of Utah, while pointing out that similar genetic variations may also occur in different proportions or in individuals of different ethnicity.
"In recent years we've seen an explosion in the understanding of how small genetic variations can impact all aspects of health, including addiction. As we learn more about how both genes and environment play a role in smoking, we will be able to better tailor both prevention and cessation programs to individuals," added Dr. Nora Volkow of the National Institute of Drug Abuse.