Originally Posted on Express UK | 20 Feb 2013
Quitting smoking could dramatically slash the likelihood of developing risks for Alzheimer’s disease, according to research. It has long been known that smoking is harmful for the health and is one of the major risk factors for developing the killer brain disease as well as a host of other chronic conditions. But now, researchers have found a direct link between smoking and Alzheimer’s, showing that the smoke from cigarettes directly causes changes in the brain which can lead to the disease. It means the estimated 10 million smokers in Britain could help protect themselves from the devastating condition by quitting the habit.
A study led by Dr Claudio Soto of the University of Texas Health Science Center in Houston, Texas, has shown that mouse models of Alzheimer’s disease exposed to cigarette smoke display increased disease abnormalities in the brain. The findings provide new insights into a potential environmental risk factor of Alzheimer’s disease.
Previous human studies have suggested that smoking might increase the risk of Alzheimer’s disease. Smoking is known to contribute to inflammation and oxidative stress, both of which are believed to be important in the development of Alzheimer’s. Others have shown that passive smokers are at a 44 per cent increased risk of developing mental decline. However, none have so far have looked directly at the effect of cigarette smoke exposure on the causes and progress of Alzheimer’s.
Now, this latest study, which is published in the journal Nature Communications found that exposing mice to cigarette smoke increases the severity of some of the abnormalities in the brain that are typical of Alzheimer’s disease, such as neuroinflammation and the build up of amyloid plaques and defective tau protein. Stopping this relentless destruction of brain cells is seen as vital in the hunt for a cure for devastating Alzheimer’s disease and other forms of dementia.
Experts believe that by preventing this cascade of destruction, stopping dementia from taking hold in the first place, is the key to eradicating it for good. Normally tau protein is a hard-working participant in memory and normal brain function. But in Alzheimer’s and other neurodegenerative diseases, it not only stops playing a productive role in brain health, it becomes a misshapen attacker that instead destroys the brain cells.
These destructive knots of tau are one of two protein abnormalities found in Alzheimer’s patients, the other being amyloid. They gather inside brain cells forming the tangles which eventually burst the cell, killing it for good. The researchers say that further studies are needed to confirm the mechanisms that are responsible for the increase in the causes of Alzheimer’s disease and whether the same effect is also seen in humans.
However, they say their results highlight cigarette smoke as an important environmental risk factor for Alzheimer’s disease. Dr Simon Ridley, Head of Research at Alzheimer’s Research UK, said:
“It’s been known for some time that smoking is harmful for our health, and observational studies have already linked smoking to an increased risk of Alzheimer’s disease. This research provides yet more evidence for a direct link between smoking and Alzheimer’s, by highlighting some changes in the brain that may result from exposure to cigarette smoke. Research to understand the underlying mechanisms involved could provide new insight to help scientists develop treatments of the future. The best evidence shows that quitting smoking can help reduce the risk of dementia, along with other lifestyle changes such as eating a healthy diet, exercising regularly and keeping blood pressure and cholesterol in check. With 820,000 people currently living with dementia in the UK and that number on the increase, research to find new treatments and preventions is vital.”