A new study has concluded that initiation into alcohol at a young age may affect the genes linked to alcoholism and make youngsters vulnerable to severe problems.
The study led by Dr Arpana Agrawal, from Washington University School of Medicine in St. Louis, revealed that the younger an individual was at first drink, the greater the risk for alcohol dependence and the more prominent the role played by genetic factors.
"There seemed to be a greater genetic influence in those who took their first full drink at a younger age," said Agrawal.
"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," she added.
During the study, the researchers studied 6,257 adult twins from Australia and measured the extent to which age at first drink changed the role of heritable influences on symptoms of alcohol dependence.
The study showed that when twins started drinking early, genetic factors contributed greatly to risk for alcohol dependence, at rates as high as 90 percent in the youngest drinkers.
The team also found that those who were 15 or younger when they started drinking tended to have a greater genetic risk for alcohol dependence.
However, some who were 16 or older before they took their first drink later became alcohol dependent, but their dependence was related more to environmental factors.
"Something about starting to drink at an early age puts young people at risk for later problems associated with drinking," Agrawal says.
"We continue to investigate the mechanisms, but encouraging youth to delay their drinking debut may help.
"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," she added.
The study will be published Alcoholism: Clinical and Experimental Research.