July 4, 2012
Men who smoke are more likely to have faster declines in memory as they age than their nonsmoking peers, a new study reports. Women who smoked did not appear to suffer the same deficits, though other studies have linked smoking in both men and women to an increased risk of dementia in the elderly.
The news offers yet one more incentive to quit smoking, and the sooner the better. After 10 years of quitting, the men who had stopped smoking had no more rapid loss of memory than men who had never smoked. The study, from the Archives of General Psychiatry, adds to a growing body of research showing that smoking has detrimental effects not just on the lungs or heart but on the brain as well.
For the study, British researchers studied the links between smoking history and cognitive decline among more than 5,000 men, and 2,000 women who were, on average, in their mid 50s when the study started. Over the next 10 years, they were given tests to measure memory and thinking skills. They also completed detailed questionnaires about their smoking habits during the previous 25 years.
The researchers found that men who smoked tended to have faster cognitive decline than men who did not. Men who continued to smoke during the study period showed the fastest decline in memory and thinking skills.
Men who had quit smoking at least 10 years earlier tended to score lower on cognitive tests than men who had never smoked. But they did not show faster rates of decline.
The researchers also noted that many earlier studies may have failed to show the full impact of smoking on the brain because smokers tend to die much younger than those who do not smoke.
The scientists were not sure why similar problems were not noted in women who smoked. One reason, they speculated, may be that women tend to be lighter smokers than men.
Source: Archives of General Psychiatry, published online February 6, 2012. doi:10.1001/archgenpsychiatry.2011.2016.