Couch potatoes at highest risk of dementia

Couch potatoes are just as likely to get dementia as those born with the Alzheimer's gene, a new study claims.This means that even without any genetic risk factors, over-65s who rarely exercise are among the most likely to develop the disease.

Currently 47.5 million people worldwide are living with dementia and that number is is set to increase to 115.4 million by 2050 due to the aging population.

But experts warn the rising rate of physical inactivity could drive up that figure even more.

With no known cure, scientists are now looking to develop new dementia prevention strategies that focus on increasing physical exercise in older adults.

The recent study followed 1,600 Canadian adults over the course of five years.

Researchers found that although carriers of a variant of the 'apolipoprotein E' genotype are more likely to develop dementia, inactivity dramatically increased the risk for non-carriers.

For those who carried the gene, the odds of developing dementia were not significantly different between exercisers and non-exercisers.

Co-author Jennifer Heisz, an assistant professor in the Department of Kinesiology at McMaster University, said: 'The important message here is that being inactive may completely negate the protective effects of a healthy set of genes.

'Given that most individuals are not at genetic risk, physical exercise may be an effective prevention strategy.'

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