Keeping a full social calendar may help protect you from dementia (痴呆症), researchers said on Monday. 1active people who were not easily stressed had a 50 percent lower risk of developing dementia compared with men and women who were 2and prone to distress, they reported in the journal Neurology. "In the past, studies have shown that long-term distress can 3parts of the brain, possibly leading to dementia," Hui-Xin Wang of the Karolinska Institute in Sweden, who led the study, said in a 4. "But our findings suggest that having a calm and 5personality in combination with a socially active lifestyle may decrease the risk of developing dementia even further." An estimated 24 million people worldwide have the memory loss, problems with direction and other 6that signal Alzheimer's disease and other forms of dementia Researchers believe the number of people with dementia may increase by four times by 2040, 7the importance of better understanding the condition. The Swedish study involved 506 elderly people who did not have dementia when first examined. The volunteers were given questionnaires about their personality traits and lifestyles and then 8for six years. Over that time, 144 people developed dementia with more socially active and less stressed men and women 50 percent less likely to be 9with the condition. "The good news is, lifestyle factors can be modified as opposed to genetic factors which cannot be controlled," Wang said. "But these are early results, so how exactly 10attitude influences risk for dementia is not clear." A. affect B. outgoing C. undergoing D. diagnosed E. effect F. Socially G. tracked H. withdrew I. Vertically J. statement K. highlighting L. symptoms M. frictions N. mental O. isolated