It is already well-known that the brains of long-term alcoholics atrophy and shrink, the study authors say, but the new findings are the first evidence that cigarette smoking might contribute to that atrophy, particularly in grey matter of the parietal and temporal lobes.
Fifty to 90 percent of alcoholics also are smokers, according to Dieter Meyerhoff, PhD, a radiology researcher at SFVAMC and the principal investigator of the study
"Just looking at the amount of tissue mass lost due to either drinking or smoking, alcoholics who smoke show a greater loss in some regions of the brain compared to alcoholics who don't smoke," says Meyerhoff, who also is a professor of radiology at the University of California, San Francisco.
The study, which was published in the August 2005 issue of Alcoholism: Clinical and Experimental Research, compared 37 recovering alcoholics between the ages of 26 and 66 with a control group of 30 healthy light drinkers. The researchers used magnetic resonance imaging, a safe, non-invasive imaging technique, to measure brain volumes of the study participants.
They discovered that the more severe the tobacco habit, the greater the brain injury. "In smoking alcohol-dependent individuals, smaller regional [brain] volumes are related to greater cigarette-smoking severity," according to the study findings, with severity measured by level of nicotine dependence, cigarettes smoked per day, and years of smoking.
The alcoholics (24 smokers and 13 non-smokers) averaged around 400 drinks per month for three years prior to the study; the light drinkers (seven smokers and 23 non-smokers) averaged between four and 11 drinks per month before the study and had no history of alcohol abuse or dependence. The alcoholics were sober for approximately one week before the
Contact: Steve Tokar
University of California - San Francisco