Rosario Sánchez Pernaute
Ikerbasque Research Professor, director of the Laboratory of Neural Reprogramming and Regeneration (Molecular Brain Lab) and assistant to the scientific director of the Health Research Institute Biobizkaia
Is the research of good quality?
“It is a well-designed and well-executed study by a group of experts in epidemiology. The analysis is meticulous. The only point to bear in mind is that the follow-up period is relatively short for diseases such as Parkinson’s disease (PD), which have a late age of onset; as a result, they may be detecting fewer cases than actually occur in that sample.”
How does it fit in with the existing evidence?
“It is consistent with epidemiological studies showing a reduced risk of developing PD among smokers, even to a greater extent than in this study.”
Could findings of this kind encourage people to take up smoking or prevent them from giving up?
“No, the health risks associated with smoking are well known and severe. In fact, the study suggests that the protective effect can be dissociated between the effect of carbon monoxide (CO) and that caused by other compounds present in tobacco, such as nicotine, which was thought to be causally linked, albeit without clear evidence. It is also true that this study cannot prove that this is not the case (regarding nicotine or other tobacco compounds), but it does provide evidence of an inverse correlation between CO levels and the risk of developing PE in non-smokers, which is the most significant finding from my point of view.”
What are the implications of these findings for clinical practice?
“At present, they have no direct clinical implications. Strategies are being explored to stimulate the production of endogenous CO as an indirect antioxidant, due to its ability to activate heme oxygenase-1 and other antioxidant mechanisms.”
Does the study have any significant limitations that need to be taken into account?
“I believe the main limitation is the relatively short follow-up period for diseases such as PD, which have a late age of onset, and perhaps the fact that only a single measurement of exhaled CO was taken, which may not be representative of actual exposure over time.”