A new study suggests that quitting smoking – even in middle age or later – can slow cognitive decline.
Although cognitive decline occurs naturally with aging, research suggests that smoking worsens it and may increase the risk of dementia.
Previous research has found that quitting smoking early can reduce these effects. Mikaela Bloomberg, epidemiologist at University College London and lead author of the article published this week, says that those who quit the habit early have cognitive scores comparable to those of people who never smoked.
She wanted to find out if quitting smoking later in life would have a similar impact.
To find out, the research team analyzed data from surveys with more than 9,000 participants aged 40 or older in 12 countries. They compared people who had quit smoking with persistent smokers according to their initial cognitive scores and other characteristics, including sex, age, education level, and country of birth.
The results showed that, for those who quit smoking, verbal fluency declined at a rate approximately half that observed among smokers. Regarding memory, the decline was reduced by 20%.
“Many older people may think it doesn’t make sense to quit smoking after decades, but our study suggests that quitting, even later in life, is associated with slower cognitive decline,” Bloomberg says.
Dr. Neal Benowitz, a cardiovascular physician and clinical pharmacologist who has studied the effects of tobacco on health, says this is a significant study, especially for older smokers.
“One of the important problems in tobacco control is that older smokers are not quitting at rates as high as younger smokers,” he says.
Benowitz adds that citing the study in campaigns encouraging older smokers to quit or switch to a non-combustible form of nicotine, such as e-cigarettes or nicotine pouches, could be a good next step.
Smokers have an increased risk of dementia, one of the leading causes of death worldwide. Cigarette smoke exposes the body to high levels of oxidative stress, explains Benowitz. This process damages cells and tissues, including small blood vessels that supply oxygen to the brain, which can result in inflammation.
It affects cardiovascular health and “can cause things like stroke,” says Bloomberg, “and all these things can impact cognitive function, as they damage the brain structures that give rise to cognitive function.” She notes that there is evidence that this can also contribute to the risk of dementia.
Bloomberg agrees that the study may motivate quitting smoking later in life.
“You might think you’d need to quit smoking at the beginning of middle age, and then you’ve kind of missed that critical period to quit. But that simply doesn’t seem to be the case here,” she says.
She adds: “It’s never too late to quit.”
Source: npr.org by Aru Nair, Regina G. Barber