Low Resistance to Alcohol Leads to Greater Risk of Alcoholism

Most of us know someone who often boasted that he or she could drink everyone under the table—and usually did. But being able to drink copious amounts of alcohol without becoming blindingly drunk will do much more harm than good in the long run, as a new study shows that young men who have a high tolerance for alcohol face a greater risk for alcoholism later in life than those who readily feel alcohol’s effects.

“If a person needs more alcohol to get a certain effect, that person tends to drink more each time they imbibe,” said Marc A. Schuckit, professor of psychiatry at the University of California, San Diego and co-author of the study. “Other studies we have published have shown that these individuals also choose heavy drinking peers, which helps them believe that what they drink and what they expect to happen in a drinking evening are ‘normal,’” Schuckit continued. “This low LR (level of response), which is perhaps a low sensitivity to alcohol, is genetically influenced.”

Since the 1970s, scientists have been investigating the apparent link between an individual’s resistance to alcohol’s effects and a higher risk of alcohol use disorders later in life. But many people didn’t believe it existed, Shuckit said. From 19877 to 1988, Schuckit and his colleagues analyzed data collected on 297 men between the ages of 18 and 25. Each participant underwent tests to measure his response to alcohol, but despite similar blood-alcohol levels, the degree of impairment varied substantially. The men also provided background information such as their body mass index, how much they typically drank, the age at which they first drank, and whether alcoholism ran in their families.

The participants were interviewed again after 10, 15, 20, and 25 years, and these follow-up interviews showed that the men who were least affected by alcohol at age 20 were two to three times as likely to be dependent on alcohol at 30 or 40. These differences in risk remained even when researchers compared only men for whom the other risk factors—how much they drank, age of drinking onset, and family history—were equal.

“A low LR at age 20 was not just a reflection of being a heavier drinker at age 20 when we tested these men, and it wasn’t an artifact of an earlier onset of drinking,” said Schuckit. “We showed that a low LR at 20 predicts later heavy drinking and alcoholism even if you control for all these other predictors of alcohol problems at age 20.” He added that the method of examination strongly shows “that LR is consistent and powerful in predicting alcoholism.”

Schuckit speculates that 60 percent of alcoholism risk is genetic and 40 percent stems from lifestyle and environmental factors; resistance to alcohol’s effects seems to be a genetic trait. Schuckit advises that “…if you’re an alcoholic, you need to tell your kids that they are at a four-fold increased risk of developing alcoholism. If your kid does drink, find out if they can ‘drink others under the table,’ and warn them that that is a major indication they have the risk themselves. Keep in mind, however, that the absence of a low LR doesn’t guarantee they won’t develop alcoholism, as there are other risk factors as well.”

Schuckit and his team are currently investigating genes that they suspect play a role in alcoholism risk. “We are looking for ways to identify this risk early in life, and to find ways to decrease the risk even if you carry a low LR … so there is hope for the future.”

Source:  Science News, Sensitivity to alcohol connected with alcoholism risk, May 2009