People who are single or widowed are at a greater risk of suffering from dementia as compared to those who are married, a study claims.

Researchers from University College London in the UK reviewed 14 existing studies.

“There is compelling research showing married people generally live longer and enjoy better health, with many different factors likely to be contributing to that link,” said Laura Phipps, from Alzheimer's Research UK.

People who are married tend to be financially better off, a factor that is closely interwoven with many aspects of our health. Spouses may help to encourage healthy habits, look out for their partner's health and provide important social support, Phipps said.

Research suggests that social interaction can help to build cognitive reserve – a mental resilience that allows people to function for longer with a disease like Alzheimer's before showing symptoms.

While people who are unmarried or widowed may have fewer opportunities for social engagement as they age, this certainly is not always the case.

This research points to differences in levels of physical activity and education underlying much of the differences in dementia risk between single, married and widowed people, Phipps said.

Staying physically, mentally, and socially active are all important aspects of a healthy lifestyle and these are things everyone, regardless of their marital status, can work towards.

“It's important to remember that this study is taking a population-level view, and age, genetic and lifestyle factors will all play a role in defining someone's risk of dementia at an individual level,” Phipps added.