The most interesting, if concerning, aspect of new research published today into the risks of developing dementia is that it concentrates on middle age, not old age. On a positive note, it shows us that there is still time to do something about this most devastating of diseases, for this and future generations. The study, by the Swedish medical university Karolinska Institutet, places the highest risk on those living alone, but the findings should be compulsory reading for everybody in the 40-60 age group, regardless of whether they are single, cohabiting, married, widowed or divorced.

The most interesting, if concerning, aspect of new research published today into the risks of developing dementia is that it concentrates on middle age, not old age. On a positive note, it shows us that there is still time to do something about this most devastating of diseases, for this and future generations. The study, by the Swedish medical university Karolinska Institutet, places the highest risk on those living alone, but the findings should be compulsory reading for everybody in the 40-60 age group, regardless of whether they are single, cohabiting, married, widowed or divorced.

The research examines the association between marital status and the risk of dementia. People who are widowed in middle age and remain living alone appear three times more likely to develop the disease later on in life. Anyone living without a spouse or partner in their middle years apparently has a much higher risk of developing cognitive impairment.

This group is expanding in size. According to the Register General for Scotland, the number of adults living alone in Scotland has increased by 6% in the past five years. Some 38% of dwellings in Scotland are entitled to a council-tax discount as there is only one adult. There are more one-adult households in urban areas (42%, compared to 29% in remote rural areas).

The research points to growing evidence of the importance of social factors in sustaining healthy brain functioning. There is perhaps a message for unmarried, especially widowed, people to increase their social engagement by taking part in cultural, social and sporting activities. Is signing up to social-networking sites such as Facebook and Twitter a possible answer? Alzheimer Scotland - Action on Dementia says that, although these sites are historically used by a younger demographic, older generations are joining in. And why not?

But reading from or typing on to a computer screen can not replace the benefits of face-to-face social interaction. When we are with another human being we are communicating on more than one level: using eye contact, engaging our verbal and cognitive skills and reading body language. The Scottish charity advises "just getting out there" and becoming involved with the community.

This can be easier said than done when circumstances cause individuals to lead lives largely in isolation. Doing so can have consequences for mental health, as the study findings demonstrate. The single life has many attractions and, while many people say they are happy to be alone, they could inadvertently be storing up problems for the future. The early onset of dementia can be difficult to detect, and can creep up unseen. Social interaction is, by its nature, a two-way street. The burden can not be put on single people alone to remain mentally fit by engaging with others: each of us has a responsibility to look out for our colleagues and neighbours.

The report is a timely reminder that there is such a thing as society, and that we must engage with it for our individual and mutual benefit, given that there has been a doubling in the number of young people living alone since the 1970s.