In a new study, researchers have found that smoking could predispose people to dementia, not protect them as it has been earlier claimed.
The human brain becomes riddled with amyloid protein plaques and tangles of tau proteins in Alzheimer's disease. Low doses of nicotine have been shown to reduce the number of plaques in rats, but till now little was known about the effect of nicotine on the protein tangles.
In order to find out, Yan-Jiang Wang's team at the Third Military Medical University in Chongqing, China, injected amyloid plaques into the brains of healthy rats and gave some the equivalent of a smoker's daily dose of nicotine for two weeks, while others received nothing, reports New Scientist.
All the rats showed early signs of tau tangles and had difficulty navigating a maze, but the rats that were on nicotine did worse than those that were not.
The study has been published in the European Journal of Pharmacology.