Last week, we reported on a new study linking air pollution and cognitive decline. Now there’s brand new evidence that smoking could significantly speed up your chances of memory loss and cognitive decline, and even your risk of dementia—especially if you also have other cardiovascular risk factors.
We’ve known for years that smoking is bad for the brain, heart and lungs. But a large population study from England, published in the November 25 issue of the journal Age and Aging, found a significant association between smoking and accelerated cognitive decline after just four years among people in an ongoing study of aging.
Although there were links with multiple cardiovascular risk factors, “smoking emerged as the most consistent predictor of cognitive decline,” concluded the study’s lead author, Dr. Alex Dregan, a public health sciences researcher at Kings College in London, and colleagues.
The study followed 8,780 men and women ages 50 and older and found declines in tests of overall cognitive ability, specific memory and executive function (e.g., verbal fluency, attention and visual scanning) after four and eight years among those with the greatest cardiovascular risks—such as high blood pressure, cholesterol and Body Mass Index—and the lowest scores were linked to smoking. When the study began, 19 percent of participants were current smokers (average age 67, about half women). After eight years, 15 percent continued to puff.
While it’s important to note that “cohort” studies such as this one can’t prove cause and effect, it adds to a growing body of evidence against smoking. The largest study to date, a 2007 meta-analysis in the American Journal of Epidemiology, encompassing almost 17,000 people, concluded that elderly smokers have greater yearly declines in mental ability.
According to the Alzheimer’s Association, Alzheimer’s disease affects 5.4 million Americans and is the sixth leading cause of death in the U.S. The U.S. Census Bureau estimates that people 65 and older with Alzheimer’s will double to about 72 million over the next 20 years, starting with the oldest “baby boomers” just now turning 65.
Right now, there’s no accepted way to prevent cognitive decline and Alzheimer’s—but quitting smoking would be a good start.