Heavy smoking doubles Alzheimer's risk

Heavy smoking doubles Alzheimer's risk

The study also found that heavy smoking greatly increased chances of another common form of dementia.Scientists in the US followed the progress of more than 21,000 middle-aged men and women for an average of 23 years.

Those who consumed more than two packets of 20 cigarettes a day had a 157 percent higher chance of suffering from Alzheimer's disease than non-smokers, reports the Daily Mail.

They also had a 172 percent increased risk of vascular dementia over the follow-up period, according to the journal Archives of Internal Medicine.Vascular dementia is the most common form of the disease after Alzheimer's, and is linked to poor blood supply to the brain.

Rachel Whitmer, from the Kaiser Permanente research institution in California, who led the research, said: "This study shows that the brain is not immune to the long-term consequences of heavy smoking.

"We know smoking compromises the vascular system by affecting blood pressure and elevates blood-clotting factors, and we know vascular health plays a role in risk of Alzheimer's disease.