Lighting up a cigarette and having a few cocktails often go hand in hand, but according to a new study, this common combination may wreak havoc on a person's mental skills.
Researchers from University College London found combined smoking and heavy drinking was associated with 36 percent faster decline in brain function, and the problem accelerates as the amount of alcohol consumed increases. People who avoid this behavior may help protect their mental skills as they get older, the study authors concluded.
"Current advice is that smokers should stop or cut down, and people should avoid heavy alcohol drinking," the study's lead researcher, Dr. Gareth Hagger-Johnson, said in a university news release. "Our study suggests that people should also be advised not to combine these two unhealthy behaviors -- particularly from midlife onwards. Healthy behaviors in midlife may prevent cognitive [mental] decline into early old age."
The 10-year study involved nearly 6,500 adults aged 45 to 69 years. The participants were asked about their smoking habits as well as the amount of alcohol they consumed. Their brain function -- including verbal and math reasoning, verbal fluency as well as their short-term verbal memory -- was also assessed three times over the course of the study.
The age effect of combined heavy drinking and smoking was the equivalent of 12 years -- two years more than the duration of the study, according to the study findings, which were published in the July 11 online edition of the British Journal of Psychiatry.
"When we looked at people who were heavy-drinking smokers, we found that for every 10 years that they aged, their brains aged the equivalent of 12 years," Hagger-Johnson explained. "From a public health perspective, the increasing burden associated with cognitive [mental] aging could be reduced if lifestyle factors can be modified, and we believe that people should not drink alcohol more heavily in the belief that alcohol is a protective factor against cognitive decline."
Although the study found an association between smoking/drinking behavior and mental function decline, it did not prove a cause-and-effect relationship.