A new study suggests people who think positively about aging are less likely to get dementia.

The condition is common among the aging population and affects 46.8 million people worldwide.

Risk factors include age, race, heart disease, baseline cognition and a specific gene (called APOE E-4).

And about 25 per cent of those who carry the gene will end up with dementia.

Researchers at Yale University looked at more than 47-hundred patients without dementia, all over the age of 60, and asked them about their beliefs on aging.

People who had more positive attitudes toward age at the start of the study had a 43.6 per cent lower risk of developing dementia over four years compared to those who had negative attitudes.

The research is in the journal Preventative Medicine.