Being married has long been linked to healthier lifestyles and longevity but is staying single better for your brain health?

A recent study by researchers from Florida State University found that single people may have a lower risk of dementia compared to married adults. The new findings could challenge the assumption that marriage protects against dementia, a progressive decline in memory, concentration and judgment. 

The study assessed more than 20,000 older adults for up to 18 years, evaluating them annually at specialized dementia clinics across the United States.

All of the unmarried adults were at least 50% less likely to develop dementia than their married counterparts. Those who never married had the lowest risk of developing dementia, including Lewy body dementia or Alzheimer’s disease. However, the difference between them and the other unmarried groups wasn’t statistically significant, according to the study, published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association.

The results were similar regardless of gender. 

• As Alzheimer’s grows, cities work to earn ‘dementia-friendly’ status
• Amid a dementia crisis, brain researchers try to recruit Black Americans

It’s unclear why these differences exist but the researchers suggest that single people have closer social ties.

“Older married individuals may have a smaller social network, tend to be less self-reliant, and may experience stressful conditions such as caregiving, which could contribute to the risk of dementia,” Selin Karakose of FSU explained. “There is some evidence that divorce can lead to greater happiness and life satisfaction, and widowed individuals may experience an increase in close network size in the years following widowhood, which could potentially protect against dementia risk. Another important possible explanation is that the findings could suggest a delayed diagnosis among unmarried individuals.”

Solo agers, those 50 and older and living alone without the support of children or a partner, are a growing demographic in the United States. Approximately 28% of people 65 and up —  22 million older adults — live alone, according to the most recent U.S. Census Bureau data. By comparison, 1 in 10 older adults lived alone in 1950.

AARP estimates that among adults 50 or older, 10% of them are considered solo agers (also known as elder orphans). An additional 11% have at least one living child but are estranged from them. Another quarter have at least one child, but not one who would be a caregiver.

More than half (57%) of the solo agers surveyed by AARP said they were satisfied with the number of friends that they have; only a third hope to find a romantic partner.

For nearly 80 years, scientists have touted the benefits of marriage, including a boost in immune function and mental health, and a reduced risk of hypertension. 

A 2018 study published in the Journal of Happiness Studies, however, suggested that those who are unhappily married are more likely to have equal or even worse health and mortality risks compared to their single counterparts.

Indeed, a recent study from the FSU research team on long-term couples found that, when partnered people were more satisfied with their relationships, they felt healthier and reported sharper memory and clearer thinking. Researchers say that examining the quality of relationships could provide a deeper understanding of the link between health and marital status.

The number of people in the United States who develop dementia annually is projected to double each year to reach about 1 million cases by 2060, and new cases per year among Black Americans is expected to triple as more Americans live longer.

This article was written with the support of a journalism fellowship from The Gerontological Society of America, The Journalists Network on Generations and The Silver Century Foundation.