Nicotine effects in an occasional cigars smoker

Dear Ask The Doctor: Does nicotine destroy brain cells that use acetylcholine? I read that nicotine causes neuronal apoptosis by cholinergic superstimulation. Nicotine latches onto the nicotinic acetylcholine receptor and stimulates the neuron to death. On the flip side, I have read that nicotine protects against Parkinson's and Alzheimer's diseases. So what is the bottom line? I am asking this because I love to smoke cigars, but if they are killing my brain cells than it is not worth it. I am not a smoker, I eat extremely clean, do not drink and exercise daily. But I enjoy drinking coffee and smoking cigars ocasionally. Given that I am very healthy, I don't think smoking a cigar every once in a while will hurt me. But if it destroys brain cells, then I will stop. Can any of you neurologists give me a definitive answer on this please? I posted this on yahoo answers, but there are only idiot laymen there. I want an answer from a true expert. Thank you.

Dear Pedro: Well, in addition to Cancer, smoking causes lung diseases as: chronic bronchitis, emphysema and exacerbation of asthma in adults and children. It is also well documented that smoking raises remarkably the risk of heart disease, including stroke, heart attack, vascular disease and aneurysm. Cigarette or Cigar smokers are 2-4 times more likely to develop coronary heart disease than non-smokers.