Parkinson’s and smoking: Exposure to carbon monoxide is linked to lower risk of disease

Exposure to higher levels of exhaled carbon monoxide is associated with a lower risk of Parkinson’s disease, even among people who have never smoked, a study suggests.1Examining data from 512 000 adults, researchers found that smokers had a 30% lower risk of developing Parkinson’s than those who had never smoked.But more surprisingly, non-smokers with signs of exposure to carbon monoxide were also found to have a lower chance of developing the progressive neurological condition.Several previous studies have documented lower risks of developing Parkinson’s disease among smokers. While nicotine has been suggested as a possible protective compound, this has not been proved.The new study suggests that exposure to carbon monoxide, a known byproduct of smoking, could be responsible for this apparent protective effect. Carbon monoxide is an invisible gas that can enter the human body through smoking and other environmental exposures such as solid fuel use.Experts, however, say that people should…