Reacción a "Exhaled carbon monoxide has been linked to a lower risk of Parkinson’s disease"

Strange as it may seem, we have known for years that tobacco use is associated with a lower risk of developing Parkinson’s disease. And, although we still do not know the reasons why, various studies point to nicotine as a possible cause. However, no improvements were observed in patients treated with nicotine patches, and some experienced a slight deterioration. This suggests that other factors may be responsible for the ‘beneficial effect’ of smoking on this condition.

This study analyses, for the first time, the possible link between tobacco use, exhaled carbon monoxide levels and the risk of developing neurodegenerative diseases, including Parkinson’s disease. To this end, a cohort of over 500,000 people, comprising both smokers and non-smokers from different regions of China, was followed up for more than 10 years. The results show that, among smokers with higher levels of exhaled carbon monoxide, the risk of developing Parkinson’s disease is reduced by up to 30 per cent, but not for other neurodegenerative diseases. However, the most interesting finding is that the risk of developing Parkinson’s disease is reduced to a similar extent in individuals—particularly women—who have never smoked but who had higher levels of exhaled carbon monoxide. This suggests that carbon monoxide may be responsible for the beneficial effects observed in the smoking population, acting as a defence mechanism. However, further research is needed to understand the mechanisms involved and to determine whether the results could be extrapolated to other populations, as the study focused on a population sample in China with specific socio-economic, environmental, cultural and genetic characteristics.

The results point to carbon monoxide produced by our own bodies as the factor responsible for the positive effects of tobacco in patients with Parkinson’s disease. Most importantly, this would diminish the role of tobacco components as protective factors against the disease. It is therefore important to emphasise that the evidence suggests the lower incidence of Parkinson’s among smokers is not directly related to the components of tobacco. Identifying factors of this kind would open the door to potential new, non-toxic and targeted treatments that could delay the progression of the disease, without the undeniable negative consequences that tobacco use has on human health.