Washington University SchoolIt is said that the age at which a person takes the first drink might influence the genes which are supposedly associated with alcoholism. This could make the youngest drinkers, more vulnerable to severe problems. At least that’s what experts from the Washington University School of Medicine in St. Louis have to say.

Researchers apparently examined about 6,257 adult twins from Australia. They wished to find out whether twins who began drinking at an early age apparently had more chances to develop a more inherited form of alcohol dependence as compared to those who started drinking later in life. It was found that, younger a person was at first drink, the larger the danger for alcohol dependence. Also the function played by genetic factors was said to be more prominent.

First author Arpana Agrawal, Ph.D, commented, “There seemed to be a greater genetic influence in those who took their first full drink at a younger age. That’s very consistent with what has been predicted in the literature and in the classification of types of alcohol dependence, but we present a unique test of the hypothesis.”

Agrawal and her colleagues apparently scanned formerly gathered data from identical and fraternal, male and female twins, via statistical techniques to gauge the degree to which age at first drink supposedly altered the function of inherited influences on symptoms of alcohol dependence. They were supposedly able to tease out genetic influences, shared environmental influences and non-shared environmental factors, by means of a twin model.

It was found out that when twins began drinking early, genetic factors apparently added greatly to the risk for alcohol dependence. It was said to be as high as around 90 percent in the youngest drinkers. For those who began drinking at older ages, genes did not clarify much, and environmental factors that apparently made twins dissimilar from each other, like exceptional life events, had an increased importance.

It was seen that the twins in the study were about 24 to 36 years old when they were interviewed. But it was shocking when it was found out that they consumed their first drink at an extremely young age of 5 or 6. The researchers discovered that people, who started drinking at an age of 15 or younger, apparently had more chances of a greater genetic risk of alcohol dependence. People who took alcohol when they were 16 or older apparently became alcohol dependent, but it was more due to environmental factors.

Agrawal quoted, “We don’t have actual gene expression data in this study, but we could hypothesize that exposure to early-onset drinking somehow modifies the developing brain. Particularly frequent or heavy early drinking may influence gene expression and contribute to more severe outcomes. Our research cannot prove that, but it’s something that neuro-imaging and gene expression studies certainly should investigate.”

One more option is that early drinking could expose adolescents to particular environment influences like their peer groups that someway develop genetic influences that may add to risk for alcohol dependence.

Agrawal, an assistant professor in the Department of Psychiatry, mentioned, “Some early-onset drinkers do not develop alcohol problems and some late-onset drinkers do — we are working on why that is the case, but it is important to note that this is one risk factor among many and does not determine whether a person will, or will not, develop alcohol dependence. But age at first drink is a well-known risk factor, and there have been two main hypotheses about why: One has been that common genetic and environmental factors contribute both to the risk for alcohol dependence and to the likelihood a person will be younger when consuming their first drink. A second hypothesis suggests starting to drink at a younger age exerts an influence on alcohol dependence that is independent of these shared factors. Our findings suggest there may be some truth to both hypotheses.”

Agrawal mentioned that examining twins could provide benefits when trying to find out about genetic and environmental influences on alcohol dependence. Differences in drinking behavior between a pair of twins might come from environmental issues, as identical twins apparently share 100 percent of their DNA. Similarities between identical twins have more chances to be influenced by genes and family environment.

The research will be published in the December issue of Alcoholism: Clinical & Experimental Research, but they are available online through the journal’s Early View.