A new study by researchers from University College London has revealed that smoking may be one of the most important lifestyle factors that negatively affects the speed at which our cognitive skills decline as we age.
The study, published in the journal Nature Communications, analyzed data from 32,000 adults over the age of 50 from 14 European countries who responded to surveys over a 10-year period.
The study examined how rates of cognitive decline differ among cognitively healthy older adults based on different combinations of health-related behaviors, including smoking, physical activity, and social interaction.
Participant classification
Cognitive function was assessed according to participants’ performance on tests of memory and verbal fluency, and participants were classified according to their lifestyle, whether they smoked, whether they engaged in moderate to vigorous physical activity at least once a week, and whether they saw friends and family at least once a week.
faster cognitive decline
The researchers found that cognitive decline was faster in people whose lifestyles included smoking, while cognitive decline was generally similar for all non-smokers.
Smokers’ cognitive scores declined over 10 years by up to 85% more than nonsmokers. The exception to this finding was that smokers who had a healthy lifestyle in all other areas—i.e., they exercised regularly and socialized regularly—had rates of cognitive decline similar to nonsmokers.
Previous evidence suggests that individuals who engage in more healthy behaviors have slower cognitive decline. However, it was not clear whether all behaviors contribute equally to cognitive decline, or whether specific behaviors drive these outcomes. The researchers took into account a range of factors that might influence the results, including age, sex, country, education, wealth, and chronic disease.
“Our study is observational, so it cannot prove cause and effect conclusively, but it suggests that smoking may be a particularly important factor influencing the rate of cognitive ageing,” lead researcher Dr. Michaela Blumberg of the School of Behavioral and Health Sciences at University College London told EurekAlert.