Alcoholics who smoke may show `early ageing` of brain

Updated: May 18, 2013, 13:00 PM IST

Washington: Heavy drinkers who smoke have more problems with their memory, ability to think quickly and efficiently, and problem-solving skills, a study has suggested.

The study looks at the interactive effects of smoking status and age on neurocognition in one-month-abstinent alcohol dependent (AD) individuals in treatment.

"Several factors - nutrition, exercise, comorbid medical conditions such as hypertension and diabetes, psychiatric conditions such as depressive disorders and post-traumatic stress disorder, and genetic predispositions - may also influence cognitive functioning during early abstinence," Timothy C. Durazzo, assistant professor in the department of radiology and biomedical imageing at the University of California San Francisco, and corresponding author for the study, said.

Alecia Dager, associate research scientist in the department of psychiatry at Yale University, said "the independent and interactive effects of smoking and other drug use on cognitive functioning among individuals with AD are largely unknown.

"This is problematic because many heavy drinkers also smoke. Furthermore, in treatment programs for alcoholism, the issue of smoking may be largely ignored.

"First, individuals with AD who also smoke may have more difficulty remembering, integrating, and implementing treatment strategies. Second, there are clear benefits for thinking skills as a result of quitting both substances," she said.

Durazzo and his colleagues compared the neurocognitive functioning of four groups of participants, all between the ages of 26 and 71 years of age: never-smoking healthy individuals or "controls" (n=39); and one-month abstinent, treatment-seeking AD individuals, who were never-smokers (n = 30), former-smokers (n = 21) and active-smokers (n = 68). Evaluated cognitive abilities included cognitive efficiency, executive functions, fine motor skills, general intelligence, learning and memory, processing speed, visuospatial functions, and working memory.

Durazzo said that the team found that, at one month of abstinence, actively smoking AD [individuals] had greater-than-normal age effects on measures of learning, memory, processing speed, reasoning and problem-solving, and fine motor skills.

He said that the AD never-smokers and former-smokers showed equivalent changes on all measures with increasing age as the never-smoking controls and these results indicate the combination of alcohol dependence and active chronic smoking was related to an abnormal decline in multiple cognitive functions with increasing age.

Dager said, "these results indicate the combined effects of these drugs are especially harmful and become even more apparent in older age."

"In general, people show cognitive decline in older age. However, it seems that years of combined alcohol and cigarette use exacerbate this process, contributing to an even greater decline in thinking skills in later years," she said.

Durazzo said that oxidative damage results from increased levels of free radicals and other compounds that directly injure neurons and other cells that make up the brain.

The results will be published in Alcoholism: Clinical and Experimental Research.