Elderly people who are single or smoke are more susceptible to dementia, a study suggests. The Ministry for Health, Welfare and Family Affairs on Monday released a survey of 8,199 people aged 65 or older across the country in 2008. It shows that elderly people without spouses are 2.4 times more likely to be afflicted with dementia, while elderly smokers were 1.5 times more likely to develop the disease than non-smokers.

Depression increased the chances of developing dementia three times. According to the survey, elderly women are 1.3 times more likely to suffer from dementia than males in the same age groups. Senior citizens with elementary education are 1.6 times more likely to suffer dementia than those with secondary or higher education. Overall, uneducated elderly people are 4.5 times more likely susceptible to the disease than the educated.

The statistics are partly attributable to the fact that women live longer than men, but also suggest that those who use their brain more are less likely to suffer dementia, the ministry said.

As Korea ages, the number of dementia cases is increasing rapidly. In 2008, 421,000 or 8.4 percent of about 5 million elderly people suffered from dementia. The figure will likely increase to 445,000 or 8.6 percent of 5.19 million elderly this year. The ministry said it estimates that the number of elderly dementia patients will double every 20 years to exceed 1 million by 2027.