Don't smoke is my reccomendation, its the most pointless, stupid thing a person can do
Thousands of Aussie smokers might disagree with that. Sure smoking is bad for the lungs and body in general, but it makes no sense to convey the message that way IMO.
There are arguments to suggest smoking may increase the risk of age related demenia, but it's also acknowledged that Nicotine
may play a role in preventing or delaying the onslaught of alzheimers by modulating cholinergic nicotinic receptors in the brain, which offers protection against beta-amyloid induced apoptosis (programmed cell death). Several nicotine related drugs are currently being assessed for this purpose.
As noted previously, nicotine can prevent beta-amyloid induced apoptosis in cultured neurons...
...Several studies indicate that incubation with nicotine or other nAChR agonists, including cytisine and DMXBA, protects cultured cells from beta-amyloid-induced apoptosis (Wang et al. 2000, Frier and Herron 2003). However, the mechanism of this is not well understood.
From
Nicotinic Acetylcholine Receptors and Alzheimer’s Disease Therapeutics: A Review of Current Literature, published in an undergrad peer reviewed journal. It offers an up to date, easy to follow review on the subject. Google will provide thousands of other articles on the topic.
My wife's grand mother lived to 97 and she loved a smoke right until the end. She was as sharp as a tack. I have another relative who is 93 and has smoked all her life. She has the mind of someone in their 30's, the wrinkle free skin of a teenager and the memory of an elephant.
My wife worked for years in aged care and always commented on how most smokers in their nineties comprised the greatest proportion of dementia free residents.
To put things in perspective; smoking does kill, but a few years of smoking in your late teens/ twenties is not thought to increase your risk of cancer anywhere near as much as with a person who has smoked for 30 years or so. While susceptible individuals may be affected by even passive smoke, most cancers and heart related problems are the result of years of exposure. So the risk is relative: age, frequency, duration etc...
For what it's worth, there are now pre-rolled cigarettes available that claim no added chemicals. I don't believe these would be that much safer to smoke in terms of possible health impacts, but they are unlikely to be any worse. One brand that seems popular is "American Spirit"