BEIJING, July 19 (Xinhuanet) -- Lifestyle changes such as exercise, eating healthily and not smoking could reduce the chances of having Alzheimer’s disease by half, researchers said in a study quoted by news reports Tuesday.

Hundreds of thousands of patients could potentially avoid the devastating illness by simply changing bad habits, according to the study published in the journal Lancet Neurology

For the first time, scientists have calculated the extent to which certain lifestyle traits -- including lack of exercise, smoking and obesity -- all contributed to the disease.

Researchers found that in the Western world, an inactive “couch potato” lifestyle was the most important possible cause.

Smoking, obesity in middle-age, high blood pressure and diabetes all increased the risk as they cause damage to blood vessels in the brain, leading to death of brain cells.

Together, the modifiable risk factors contributed to 50 percent of Alzheimer’s cases worldwide.

The researchers want to carry out more work to find out how many people can prevent the disease by making small changes to their lifestyle.