Participants took various physical and biological measurements, including thinking and memory tests to assess their cognitive function. In an attempt to measure social isolation, participants were asked whether they participated in social activities at least once a week,; and whether they lived with others; and whether they had visits with friends or family at least once a month. Those who answered no to at least two of these questions were considered socially isolated.
Of the 41,886 participants who were considered under social isolation, 649 developed dementia, or 1.55%, compared to 4,349 people of the 420,733 participants who were considered not socially isolated, or 1.03% of the participants.
The researchers considered other factors including age, sex, socioeconomic status, alcohol intake and smoking, and other conditions like depression and loneliness, and found that socially isolated individuals had lower volume in the brain’s gray matter in various regions involved with learning and thinking. The study found that people who were considered socially isolated were 26% more likely to develop dementia than those who were not considered to be in social isolation. Therefore, helping people feel more connected to their social network may have serious implications for their health, such as developing dementia at a faster pace. Helping people stay socially connected can potentially have a significant impact on our mental and brain health.