The prevalence of both Alzheimer's disease and other dementias was similar in both smokers and non-smokers.

BBC: Smoking 'does not prevent Alzheimer's'

Finding treatments for Alzheimer's and other dementias is no easy task, but it's one we must tackle if we are to make a real difference to people's lives.

BBC: Million 'dementia friends' wanted for training

Less is known about the treatment of other common dementias.

CNN: Better understanding of dementia leading to more effective therapies

While cholinesterase inhibitors are useful in many early dementias, studies have not shown that treatment of patients with mild cognitive impairment, which is the condition before dementia, prevents or slows progression to dementia.

CNN: Better understanding of dementia leading to more effective therapies