While most of the risk factors for the Alzheimer’s development at some moment later in life are linked to the physical conditions, there are multiple new discoveries, pointing that mental and psychological factors might be also significant contributors to the overall potential threat.
Today we will review the risk factor for Alzheimer’s development which cannot be considered obvious and self-explanatory. It is feeling lonely subjective perception. Yes, loneliness or social isolation is traditionally related to poorer health outcomes and life expectancy. The Amsterdam Study of the Elderly suggests that it may also be linked to increased risks of Alzheimer’s disease. However the study found that it is feeling lonely, rather that actually being alone, may be what matters.
This 3-year Dutch study tested the association between social isolation (living alone, unmarried, without social support), feelings of loneliness and incident dementia in a cohort study among 2173 non-demented community-living older persons. Participants were followed for 3 years when a diagnosis of dementia was assessed (Geriatric Mental State (GMS) Automated Geriatric Examination for Computer Assisted Taxonomy (AGECAT)). Logistic regression analysis was used to examine the association between social isolation and feelings of loneliness and the risk of dementia, controlling for sociodemographic factors, medical conditions, depression, cognitive functioning and functional status.
At the start of the monitoring period, around half (46%; 1002) the participants were living alone and half were single or no longer married. Around three out of four said they had no social support. Around one in five (just fewer than 20%; 433) said they felt lonely.
Among those who lived alone, around one in 10 (9.3%) had developed dementia after three years compared with one in 20 (5.6%) of those who lived with others. Among those who had never married or were no longer married, similar proportions developed dementia and remained free of the condition. But among those without social support, one in 20 had developed dementia compared with around one in 10 (11.4%) of those who did have this to fall back on.
And when it came to those who said they felt lonely, more than twice as many of them had developed dementia after three years compared with those who did not feel this way (13.4% compared with 5.7%). Further analysis showed that those who lived alone or who were no longer married were between 70% and 80% more likely to develop dementia than those who lived with others or who were married.
And when it came to those who said they felt lonely, more than twice as many of them had developed dementia after three years compared with those who did not feel this way (13.4% compared with 5.7%). Further analysis showed that those who lived alone or who were no longer married were between 70% and 80% more likely to develop dementia than those who lived with others or who were married.
And those who said they felt lonely were more than 2.5 times as likely to develop the disease. And this applied equally to both sexes. When other influential factors were taken into account, those who said they were lonely were still 64% more likely to develop the disease, while other aspects of social isolation had no impact.
The authors, led by Dr Tjalling Jan Holwerda, from VU University Medical Centre in Amsterdam, wrote: "These results suggest that feelings of loneliness independently contribute to the risk of dementia in later life. Interestingly, the fact that 'feeling lonely' rather than 'being alone' was associated with dementia onset suggests that it is not the objective situation, but, rather, the perceived absence of social attachments that increases the risk of cognitive decline."
How can these results be explained?
1. It is possible that the feeling of loneliness itself contributes to increasing the incidence rates of dementia. This may happen because feeling lonely increases stress and distress levels which are themselves associated with increased risks of cognitive decline.
2. It is possible that the feeling of loneliness is in fact a sign of early dementia (rather than its cause). As social and other cognitive skills decline because of the disease, individuals may feel more isolated and lonely.
It is thus not clear so far whether feeling lonely is a possible risk factor for Alzheimer’s or a result of the disease. If the former is true though, it is interesting to think that a feeling rather than an objective situation could impact health outcomes so dramatically. Remember that actually being alone did not impact health in the study.
A decrease in cognitive score (MMSE) was also significantly greater for those experiencing feelings of loneliness, suggesting that this is also a factor in age-related cognitive decline.
This shows the power of thoughts over our body. Brain plasticity and body health in general can be largely impacted by the way we think, not just by the way we behave. Physical and mental exercise and a balanced diet may not be enough to reduce dementia risks. Managing stress, promoting positive thoughts, and laughing often are also probably necessary ingredients for a good brain health.
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