Smoking interferes with the brain's ability to recover from the effects of chronic alcohol abuse

Mar 19 2006

Smoking appears to interfere with the brain's ability to recover from the effects of chronic alcohol abuse, according to a study conducted by researchers at the San Francisco VA Medical Center.

After one month of sobriety, recovering alcoholics who smoked showed significantly less improvement than those who did not smoke in both brain function and neurochemical markers of brain cell health.

"This study suggests that for better brain recovery, it may be beneficial for alcoholics in early abstinence to stop smoking as well," concludes Dieter Meyerhoff, Dr.rer.nat., a radiology researcher at SFVAMC and the senior author of the study. Meyerhoff is also a professor of radiology at the University of California, San Francisco.

The study appears in the March 2006 issue of Alcoholism: Clinical and Experimental Research.

At the outset of the study, the authors examined 25 recovering alcoholics - 14 smokers and 11 nonsmokers - using spectroscopic imaging, a magnetic resonance imaging technique. The subjects' brains were measured for two important metabolites: N-acetylaspartate (NAA), a marker of neuronal viability, and choline, a marker of cell membrane health.

After one month of abstinence from alcohol, the subjects' brains were re-examined, and the brains of the nonsmokers showed significant increases in NAA and choline.

"We did not see the same pattern or magnitude of recovery in chronic smoking alcoholics who continued to smoke during this early stage in recovery," reports lead author Timothy Durazzo, PhD, a research scientist at SFVAMC. "In fact, in the smoking alcoholic group, we saw a decrease in NAA and choline-containing metabolites in parietal and occipital white matter." The parietal lobe plays an important role in sensory processing and object manipulation. The occipital lobe controls visual processing.

The study participants' visual-spatial learning and memory, attention and concentration, and overall processing speed were also evaluated at the beginning of the study and after one month. Among the non-smokers, the greater the increases in NAA and choline in certain brain regions, the greater the improvement in visual-spatial learning and memory and attention and concentration.

"We observed no such short-term cognitive improvements among the smoking recovering alcoholics," says Durazzo. "And the relationships between metabolic brain recovery and neurocognition were not as pronounced, and in many cases were absent, in the smoking group."

The study authors caution that their results are preliminary and need to be replicated in a prospective study of a larger, entirely different population. If they are, says Meyerhoff, then professionals who treat alcoholism may wish to consider adding smoking cessation to their usual treatment plans.

"This may be a lot to ask from an alcoholic individual going through drastic brain chemical imbalances in early recovery," he acknowledges. "But it may lead to faster brain recovery."

Durazzo points out that while severe, such a strategy might be effective because among alcoholics, "cigarettes and alcohol tend to go together. One may elicit cravings for the other. So if you are able to give up both at the same time, it may increase your chances of staying sober, because you don't have one substance serving as a trigger for use of the other."

Durazzo says the study also raises the question of whether smokers respond differently than nonsmokers to current pharmacological treatments for alcoholism: "Do these alterations in brain chemistry have implications for pharmacological treatments of both smoking and alcohol abuse? That remains to be seen."

For their next step, Meyerhoff, Durazzo, and their research team plan to analyze their study participants' brain chemistry and neurocognitive performance after six months of sobriety, which they hope will give insight into differences in long-term recovery between the two populations.

The researchers also plan to study an entirely different group of smoking and nonsmoking recovering alcoholics. That study will look at whether other health factors, including diet, exercise, and general health, affect the brain's recovery from alcohol abuse.