Smoking may be one of the most important lifestyle factors influencing how quickly our cognitive skills decline as we age, suggests a new study led by UCL researchers.
The study, published in Nature communicationsanalyzed data from 32,000 adults aged 50 and over from 14 European countries who responded to surveys over 10 years.
The researchers investigated how rates of cognitive decline might differ among cognitively healthy older adults with different combinations of health-related behaviors, including smoking, physical activity, alcohol consumption, and social contact.
Cognitive function was assessed according to participants’ performance on tests of memory and verbal fluency. Participants were grouped into lifestyles based on whether or not they smoked, whether they did moderate to vigorous physical activity at least once a week, whether they saw friends and family at least weekly, and whether they drank more or the same/less than two alcoholic drinks per day ( men) or one drink per day (women).
They found that cognitive decline was faster for lifestyles that included smoking, while cognitive decline was generally similar for all non-smoking lifestyles. Smoking lifestyles had cognitive scores that declined up to 85% more over 10 years than nonsmoking lifestyles.
The exception were smokers who had a healthy lifestyle in all other areas – that is, they exercised regularly, drank alcohol in moderation and socialized regularly. This group had a rate of cognitive decline similar to non-smokers.
Our study is observational, so it cannot definitively determine cause and effect, but it does suggest that smoking may be a particularly important factor influencing the rate of cognitive aging.
Previous evidence shows that people who engage in healthier behaviors have slower cognitive decline. However, it was not clear whether all behaviors contributed equally to cognitive decline or whether there were specific behaviors that drove these results.
Our findings suggest that among the healthy behaviors we examined, not smoking may be among the most important in preserving cognitive function.
For people who cannot quit smoking, our results suggest that engaging in other healthy behaviors such as regular exercise, moderate alcohol consumption, and social activity may help offset the adverse cognitive effects associated with smoking.” .
Dr Mikaela Bloomberg, Lead Author, UCL Behavioral Science & Health
The researchers accounted for a number of factors that may have influenced the findings, including age, gender, country, education, wealth and chronic conditions.
The team used data from the English Longitudinal Study of Aging (ELSA) and the Survey of Health, Aging and Retirement in Europe (SHARE). ELSA is funded by the National Institute for Aging and UK government departments coordinated by the National Institute for Health and Care Research (NIHR). SHARE receives funding from the European Union. The study authors received funding from the Economic and Social Research Council.
Source:
Journal Reference:
Bloomberg, M., et al. (2024). Healthy lifestyle and cognitive decline in middle-aged and older adults living in 14 European countries. Nature communications. doi.org/10.1038/s41467-024-49262-5.
