I’d previously written on the ability of coffee to reduce the risk of Parkinson’s disease (PD). Coffee is not a cure, but a strong preventative for PD, reducing the risk by about 50%, assuming you drink 5+ cups per day, and proportionally for less coffee consumption. Similar to this, smoking reduces PD risk by as much as 50%. As with coffee, this is not a cure, but a prevention, smokers vs. never-smokers that is not explained by mortality, duration, or recency. It’s also confirmed by family-based studies including twin studies suggesting that genetics isn’t part of how this works. The figure below from the journal of Neurology gives a sense of this.
This is not to say that you should start smoking. Cigarettes have tars that are definitely bad, cancer causing. Still, perhaps one needn’t be as anti smoking or vaping as the public has gotten. It’s also a starting point for research.
It seems that there are two things in cigarettes that protect against Parkinson’s. The first appears to be nicotine. We know this because chewing tobacco is shown to be protective at a rate similar to smoking. Another protective component appears to be carbon monoxide. Here is a study showing that low concentration carbon monoxide protects against Parkinson’s. The Michael J foundation is funding further studies on CO because low level CO seems promising as a treatment. There are also drugs that release compounds similar to CO that might treat, or prevent Parkinson’s.
Reduced rates of smoking has been cited as an explanation for the increasing PD rates world-wide. Similar to coffee and smoking, there are also health benefits for small amounts of radiation, sunlight, and chocolate. What is a healthy food has never been settled science; the data is entirely contradictory. All this is to say, that wide bans on big sodas, smoked meats, chewing tobacco, or e-cigarettes probably are misguided. For all we know they may be good for public health, and certainly aren’t sot bad as to justify wide bansand condemnations.
Robert Buxbaum October 28, 2025.