If I told you that leaving your marriage or remaining single could reduce your risk of developing dementia, would you trust me? Unmarried persons are less likely to get dementia, according to a recent study done by experts at Florida State University. This finding is quite shocking.
You are right if you believe you have heard the opposite. Unmarried adults had “significantly higher odds of developing dementia over the study period than their married counterparts,” according to a 2019 American study.
Married people are, in fact, usually believed to be healthier. According to studies, they typically live longer and have a lower risk of heart disease and stroke. Why, then, did the recent study arrive at this unexpected conclusion? Let us examine it more closely.
The researchers analysed data from more than 24,000 Americans without dementia at the start of the study. Participants were tracked for up to 18 years. Crucially, the team compared dementia rates across marital groups: married, divorced, widowed and never-married.
At first, it looked as though all three unmarried groups had a reduced risk of dementia compared with the married group. But, after accounting for other factors that could influence the results such as smoking and depression, only divorced and never-married people had a lower risk of dementia.
Depending on the type of dementia, differences were also seen. For instance, the most prevalent type of dementia, Alzheimer’s disease, has been consistently associated with a lower likelihood of unmarried status. However, it was not demonstrated for vascular dementia, a less common type of the illness.
The researchers also discovered that those who were bereaved during the study had a lower risk of dementia, and those who were divorced or had never married had a lesser chance of developing dementia from moderate cognitive impairment.
Possible Explanations
One explanation for the surprising outcomes? When a married person’s spouse notices memory issues and insists on seeing a doctor, they may receive a diagnosis sooner. This may give the impression that dementia is more prevalent in married persons than it actually is.
Data that is biased due to who is diagnosed or noticed more readily is known as ascertainment bias. The evidence for this was weak, though. A physician, who might be viewed as a surrogate partner who would identify early indicators of dementia in the person, visited each participant once a year.
Perhaps it was the case that the sample of people used, from the National Alzheimer’s Coordinating Center (NACC) study, was not representative of the wider population. Specifically, the sample showed low levels of ethnic and income diversity. Also, nearly 64% of the participants were married. This may affect how these unexpected findings translate to the wider world. They could just have been unique to NACC participants.
It is more likely, though, that these results demonstrate the complexity of the ways in which marital disruptions, changes, and decisions affect brain health. An prior meta-analysis (a review of research) revealed conflicting findings, indicating that marriage is by no means a proven protective factor against dementia.
The latest Florida State University study, which has a lot of weight, looks at this problem using one of the largest datasets to date. It draws attention to the fact that presumptions based on earlier research that divorce and widowhood are extremely stressful life events that can cause Alzheimer’s disease or that single persons are more likely to have dementia because they are socially isolated may not necessarily be true.
Relationship dynamics are by no means straightforward. As mentioned in the paper, such dynamics may “provide a more nuanced understanding than a simple binary effect”. Factors such as marriage quality, levels of satisfaction after divorce, cultural considerations, or the sociability of single people compared with coupled ones may help explain these seemingly contradictory results.
This study challenges the idea that marriage is automatically good for brain health. Instead, it suggests the effect of relationships on dementia is far more complex. What matters might not be your relationship status but how supported, connected and fulfilled you feel.
(Disclosure Statement: Avinash Chandra does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.)