From Wednesday's Globe and Mail
When Rebekah Grant was 11 years old, it took only a sip of wine with her parents for her to feel a buzz. By 13, she found herself needing more like a couple of glasses to get the same result.
Now, the 15-year-old says she can tolerate alcohol better than her parents can.
"I would get pissed [drunk] with just one sip back then," said the teen, who is visiting Toronto from Scotland. "I wish it was still the same now."
A new study has found that Rebekah isn't alone in experiencing this condition: Teenagers, as a whole, are naturally less sensitive to the effects of alcohol than are adults, and need more drinks per occasion to reach the same level of intoxication.
But the findings hardly merit a toast -- this so-called "safeguarding effect" is linked to potential damage in the brain and a strong dependence on alcohol later in life.
The study by Binghamton University researchers in New York shows that teens are physiologically able to compensate for the impairing effects of alcohol because their brains are built to handle stressful events better than adults.
"What I find really interesting is that they are also less sensitive than adults to hangover-related effects," said Elena Varlinskaya, a research professor of psychology at Binghamton and lead author of the study published in the November issue of Alcoholism: Clinical & Experimental Research.
The results of the study could explain why adults often say they can't hold their alcohol as well as they used to, said Anh Le, a senior scientist at the Centre for Addiction and Mental Health in Toronto.
The teenage brain is under a lot of stress and can adapt quickly when new substances are introduced to the body. This "plasticity" of the brain decreases with age and the brain becomes fully developed.
But, he warns, the implications of teens being less sensitive to alcohol has major setbacks.
"Because the brain is still developing, taking [in] more alcohol can lead to a lot of damage, even memory impairment," Dr. Le said. "And we know that 70 to 80 per cent of people who are alcohol-dependent in adult life started off with heavy alcohol consumption in adolescence."
These results are backed by a study published earlier this year in the journal Archives of Pediatric & Adolescent Medicine, which found that 14- to 19-year-olds who drink are 45 per cent more likely to become alcohol-dependent later in life than those who start drinking after the age of 20.
Binge drinking, or having five or more drinks on one occasion, has been a serious issue in Canada.
In 2001, more than one-quarter (27.5 per cent) of Ontario students in Grade 7 to OAC reported binge drinking at least once during the four weeks before the Ontario Student Drug Use Survey. Among all students surveyed, 6.2 per cent reported binge drinking at least four times during the four weeks before the survey. Among university students aged 19-24, 72 per cent binged at least once in the 12 months before the 1998 Canadian Campus Survey.
Because testing the effects of alcohol on teenagers cannot be done for legal and ethical reasons, the researchers used rat models. Adolescent rats are similar to human adolescents because they spend more time in social interactions than the younger and the older animals, Prof. Varlinskaya said.