A new study suggests that quitting tobacco can help lower the risk of dementia, but reducing smoking does not.
The researchers, led by senior author Dong Wook Shin, MD, DrPH, Sungkyukwan University School of Medicine, Seoul, South Korea, Samsung Medical Center, found some unexpected results. bottom. Increased risk of dementia.
“This cohort study showed that smoking cessation is associated with a reduced risk of all dementias. [Alzheimer’s Disease and vascular dementia], compared with sustained smoking intensity. However, reduced smoking was associated with increased risk of dementia. Therefore, to reduce the disease burden of dementia, the emphasis should be on quitting rather than reducing smoking,” the researchers wrote.
research is publish online January 19th JAMA network open.
reduction strategy?
Several observational studies have shown that smoking cessation is associated with a reduced risk of dementia. However, the researchers say their study is the first to examine a link between changes in smoking intensity and dementia risk.
This cohort included 789,532 South Korean adults (96% male, mean age 52 years) who underwent biennial health examinations (2009 and 2011) and were currently He was a smoker and was followed up until the end of 2018.
Most participants had smoked for 20 years or more (80%). By the 2011 test, approximately 15% had quit smoking, 22% had reduced smoking, and 16% had increased tobacco use.
During a median follow-up of 6.3 years, 11,912 cases of dementia occurred. This includes 8800 Alzheimer’s disease (AD) and her 1889 patients. vascular dementia (what).
Smoking cessation was associated with a reduced risk of dementia compared with sustained smoking intensity (8% reduction in all dementias, 6% reduction in AD, and 16% reduction in VaD).
The findings are consistent with previous studies showing that smoking cessation is associated with a lower risk of dementia, the researchers note.
The effect of smoking cessation on dementia risk was evident in younger but not older age groups. This suggests that quitting smoking at a younger age is associated with greater benefits than quitting smoking at an older age.
The phenomenon of “quitting due to illness”?
Strikingly, reducing tobacco use was associated with an increased risk of all dementias compared with continuing to smoke: reducing the number of cigarettes smoked per day by more than 50%. Those who smoked fewer cigarettes had a 25% increased risk, and those who smoked fewer cigarettes had a 6% increased risk.20%-50% of the number of cigarettes smoked per day.
“One possible explanation for this finding is the ‘disease smoking cessation’ phenomenon, where a reduction or cessation of smoking may indicate a change in behavior from a health concern toward a healthier lifestyle.” there is,” the authors said.
Compensatory smoking of reducing agents is another potential explanation. “Reducers may inhale deeply to maintain nicotine levels, which may negate any potential health benefits,” the researchers note.
“Although there is no benefit from reducing smoking on dementia risk, smoking cessation interventions may be an important first step toward quitting smoking,” they add.
Limitations of this study include lack of information on education or apolipoprotein E ε4 levels, which may be associated with dementia risk, and lack of information on passive smoking, types of tobacco used, and duration of abstinence. It is included.
Also, the relatively short follow-up of 6 years may not be sufficient to fully elucidate the association between changes in smoking and dementia risk.
Furthermore, the effect size of smoking cessation was relatively small (adjusted hazard ratio, 0.92). However, given the prevalence of dementia and smoking rates, the public health impact is still substantial, the authors say.
There was no specific funding for this study and the authors have declared relevant financial ties.
JAMA net openPublished online on January 19, 2023. full text
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