The study published today in the Journal of Neurology Neurosurgery & Psychiatry suggests tying the knot can lower the risk of developing dementia.
Combining the results of 15 studies, including data on more than 800,000 participants, the new analysis finds that people who remain single are at a 42 per cent greater risk of developing dementia than people who are married.
Widowers were found to be 20 per cent more likely to develop the condition.
There was no difference in the risk of dementia between those who were married and divorced.
The researchers suggest that part of this risk may be explained by poorer physical health among lifelong single people.
Bereavement is likely to boost stress levels, which have been associated with impaired nerve signalling and cognitive abilities.
As these findings are based on observational studies, no firm conclusions about cause and effect can be drawn.
But the researchers suggest that marriage may help both partners to have healthier lifestyles, including exercising more, eating a healthy diet, and smoking and drinking less, all of which have been associated with lower risk of dementia.
Dr James Pickett, head of research at Alzheimer’s Society, said: “Recently, a number of studies exploring the link between marital status and dementia risk have hit the headlines. As this research combines evidence from 15 different studies, we can be more confident in the conclusion that married people, on average, have a reduced risk of dementia compared to those who are single.
“These studies can’t tell us what it is about married life that is important for brain health, but the analysis hints that poorer physical health among those who remain single is partly responsible.
“The daily social contact that inevitably comes with marriage may also play a role, but more research is needed to confirm this is the case.
“Unfortunately for Harry and Meghan, I highly doubt marriage itself is a magic remedy for dementia – the positive benefits it may bring to combat loneliness and improve physical health can be achieved in other ways.
“The best advice for people who are worried about dementia is to maintain good physical health by eating a balanced diet, taking regular exercise and properly managing diabetes and high blood pressure, alongside regular social and mental stimulation.”
Vitamin D has been claimed to reduce the risk of heart disease, multiple sclerosis, and even rheumatoid arthritis.
But, some scientists have also found that a vitamin D deficiency could increase the risk of developing dementia.