In older adults, having friends decreases rates of dementia as well as death as the result of illness. Studies have shown that people who have positive and satisfying relationships with family, friends and community, are happier, live longer and have fewer health problems.
In contrast, lack of social ties in older adults has been associated with increased risk of cognitive decline, depression and mortality from illness. Friendship helps relieve stress, and the reduction of stress can affect the immune system, coronary arteries, gut function and insulin regulation. In addition, one particular study has found that people over the age of 75 with satisfying relationships with friends and family had the lowest risk of dementia.