Smokers Have Lower Parkinson's Risk. Scientists May Know Why
Several studies found a consistent inverse relationship between cigarette smoking and the risk of developing Parkinson’s disease.
Recent research has revealed that cigarette smokers and tobacco users tend to have a lower risk of developing Parkinson's disease compared to the general population. A 2020 study published in the journal Neurology found that smokers had a 30 to 40 percent lower risk of developing Parkinson's disease compared to non-smokers. Another study published in 2002 in the same journal investigated the link between Parkinson's risk and identical twins, concluding that those without the disease tended to smoke more than those with the disease, suggesting smoking could be protective against the condition.
A new study published this month suggests that carbon monoxide, a poisonous gas found in cigarette smoke, may be the reason behind the surprising association. While the study does not claim that smoking is good for the brain, it indicates that high levels of carbon monoxide could potentially protect vulnerable dopamine-producing brain cells from oxidative stress, inflammation, and cell death.
The study involved over 500,000 participants and found that individuals with higher exhaled carbon monoxide levels had a 30 percent lower risk of Parkinson's disease, even among those who had never smoked.
Experts from the University of Oxford and Tongxiang and Beijing in China concluded that the association may not be with tobacco smoking itself, but with carbon monoxide. Dr. Michael Okun, a professor of neurology at the University of Florida, emphasized that smoking is a major public health concern, causing over 16 million Americans to suffer from smoking-related diseases and leading to over 480,000 deaths annually in the U.S.
Researchers from the U.S. and China propose that carbon monoxide could influence pathways related to oxidative stress, inflammation, and cell survival, potentially protecting dopamine-producing brain cells. However, the exact mechanism remains unclear. Other experts suggest that the neuroprotective effects may be due to components found in tobacco leaves, such as compounds that inhibit the MAO-B enzyme, which breaks down dopamine in the brain.
This could explain why smokeless tobacco use, which contains tobacco leaves, has also been associated with a reduced risk of Parkinson's disease.
Written by urgent.news from Newsweek's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
