Older people who report feeling lonely are more likely to develop Alzheimer’s disease and other forms of dementia, according to a new study from the Netherlands. The subjective feeling of being isolated and alone appeared to be a risk factor for Alzheimer’s, regardless of whether someone was married or had a social network.
For the study, researchers followed 2,173 seniors, ranging in age from 65 to 86. None had dementia at the start of the study, which lasted three years. The researchers assessed their degree of social isolation, including whether they lived alone and lacked a spouse, partner or network of friends, as well as how lonely they reported feeling. About half lived alone, and one in five reported feeling lonely.
The study participants also were given memory and thinking tests to look for signs of serious memory loss and incipient Alzheimer’s disease.
After controlling for factors like socioeconomic status and concurrent medical problems, including depression or cardiovascular disease, the researchers found that those who felt lonely were more likely to develop dementia. Those who were socially isolated but didn’t feel lonely, on the other hand, were not at increased risk of developing dementia.
The researchers concluded that “feeling lonely,” as opposed to “being alone,” could be considered a major risk factor for Alzheimer’s disease. “It is not the objective situation, but rather the perceived absence of social connections, that increases the risk of cognitive decline,” they wrote. A better understanding of why people feel lonely “may help us to identify vulnerable persons and develop interventions to improve outcome in older persons at risk of dementia.” The study was published in the Journal of Neurology, Neurosurgery and Psychiatry.
Other research has suggested that having a rich social network can improve overall health and guard against dying prematurely from heart disease and stroke. Some studies have also suggested a link between loneliness and Alzheimer’s risk. An earlier report from Rush University Medical Center in Chicago, for instance, found that people who feel lonely may be twice as likely to develop Alzheimer’s disease in their later years as those who feel they have a close network of friends and family. But scientists are unclear how or why feeling lonely may contribute to dementia risk.
It is possible that feelings of loneliness may cause changes in the nervous system that dampen connections between brain cells, making the brain less able to protect itself against the onslaught of Alzheimer’s. Alternatively, the fear and feelings of depression that may accompany the early onset of dementia symptoms may make people feel more lonely and isolated.
Alzheimer’s is a complex disease that likely has a variety of causes. The genes you inherit, advancing age, exercise habits, the foods you eat, how socially and intellectually engaged you are, and many other factors may all influence who develops Alzheimer’s in old age, and who remains mentally sharp and alert.
Source: Tjalling Jan Holwerda, Dorly J H Deeg, Aartjan T F Beekman, et al: Research paper: Feelings of loneliness, but not social isolation, predict dementia onset: results from the Amsterdam Study of the Elderly (AMSTEL). Journal of Neurology, Neurosurgery and Psychiatry.