While the number of smokers is at a historical low, data demonstrates that smoking still affects public health. Smoking increases the risk of heart and lung disease, affects bone health, and increases the risk of birth defects. A growing body of research demonstrates that smoking also affects neurological health, specifically cognitive decline.
A longitudinal study published this fall in the journal Nature Communications tracked data from 32,000 adults between ages 50 and 104 for 15 years to identify lifestyle factors linked to cognitive decline. The surveys, conducted in 14 European countries, asked about a broad range of lifestyle factors including smoking, alcohol consumption, physical activity, and social contact. The surveys also measured episodic memory and verbal fluency, two domains affected by dementia.
Researchers found that most participants showed some signs of cognitive decline over the course of the study, but current smokers demonstrated the largest and most significant levels. The only exception were current smokers who had other healthy habits including avoiding or limiting alcohol, moderate to vigorous physical activity, and regular social contact; those participants showed less cognitive decline, similar to that of nonsmokers.
“The key finding arising from this examination of healthy lifestyle and 10-year cognitive decline is that associations between lifestyle and cognitive decline primarily depended on whether participants reported smoking,” the authors wrote.
The study offers unique insights because it followed a large group of older adults for a long period of time. The authors did highlight some limitations of the study: Behaviors were self-reported, which could lead to reporting errors, and some factors affecting dementia, such as medications, diet, and sleep, were not measured.
Nonetheless, the study demonstrates some clear associations between smoking and cognitive decline, which is important because there is clear evidence that delaying mild cognitive decline—a precursor to more serious conditions like dementia and Alzheimer’s disease—can delay those more serious conditions by up to three years. This new study suggests that not smoking could be enough to lead to this delay. And if quitting smoking isn’t feasible, focusing on other healthy habits could help to compensate for the smoking.
The take-home message: Not smoking is one of the best ways to decrease your risk of cognitive decline later in life. Other lifestyle habits, including regular physical activity, social contact, and limited alcohol use, are also keys to avoiding or delaying cognitive decline later in life.
