There is a wealth of scientific evidence proving that smoking is not only very harmful to health, but it may also be one of the lifestyle factors that most influences the acceleration of cognitive loss as we age, according to a new study led by researchers at University College London (UCL).
Researchers analyzed data from 32,000 adults aged 50 or older from 14 European countries who responded to surveys over 10 years to find out how rates of cognitive decline might differ among cognitively healthy older adults with different combinations of health-related habits, including smoking, physical activity, alcohol consumption and social relationships.
Cognitive function was assessed based on participants’ performance on memory and verbal fluency tests. Participants were grouped into lifestyle groups based on whether they smoked or not, whether they engaged in moderate to vigorous physical activity at least once a week, whether they saw friends and family at least once a week, and whether they drank more than or the same/less than two alcoholic drinks per day (men) or one drink per day (women). In addition, a number of factors that could influence the findings were taken into account, including age, sex, country, education, purchasing power, and chronic diseases.
Offsetting adverse cognitive effects associated with smoking
The results have been published in Nature Communications and show that cognitive decline was faster in people with lifestyles that included smoking, while it was generally similar in all those who did not smoke. Smokers’ lifestyles had cognitive scores that declined up to 85% more over 10 years than non-smokers’ lifestyles.
However, one exception was found: smokers who had a healthy lifestyle in all other areas – that is, they exercised regularly, drank alcohol in moderation and socialised regularly. This group had a rate of cognitive decline similar to that of non-smokers.
“Among the healthy behaviors we examined, not smoking may be among the most important in terms of maintaining cognitive function.”
Lead author Dr Mikaela Bloomberg (UCL Behavioural Science & Health) said: “Our study is observational so cannot definitively establish cause and effect, but it suggests that smoking might be a particularly important factor influencing the rate of cognitive ageing.”
“Previous evidence suggests that people who engage in healthier behaviors have slower cognitive decline; however, it was unclear whether all behaviors contributed equally to cognitive decline, or whether there were specific behaviors that drove these outcomes. Our findings suggest that among the healthy behaviors we examined, not smoking may be among the most important in terms of maintaining cognitive function.”
“For people who are unable to quit smoking, our results suggest that adopting other healthy behaviors, such as regular exercise, moderate alcohol consumption, and being socially active, may help offset the adverse cognitive effects associated with smoking,” he concludes.
