Living longer is a benefit only if those extra years can be spent free of serious illness and debilitating conditions.

That makes the latest statistics on life expectancy, showing that Scots can expect a longer period of poor health in old age, extremely gloomy news, especially for Scottish men.

We have known for some time that, on average, both men and women in Scotland are likely to die sooner than their counterparts in England. The latest figures from the Office for National Statistics (ONS) dispel any notion that men in Scotland can look forward to a healthier old age than previous generations.

The most striking finding is that, while people in England and Wales are not only living longer but enjoying more years in good or very good health and free from a limiting illness or disability, older people in Scotland (and Northern Ireland), especially men, are experiencing longer periods of illness and living for a shorter time. Scottish men are the only group to show a decrease in healthy life expectancy, with the age at which illness is likely to strike dropping from 61.2 to 59.8. Scottish women can expect to remain healthy until the age of 64.1.

While some slowing down and a few aches are part of the ageing process, feeling fit is the key gauge of a contented old age. Inevitably the proportion of life in which they could expect to feel fit after the age of 65 plummeted for Scots men (from 62% to 52%); it also dropped slightly for Scottish women but changed little for men in England and improved for English women.

This has serious implications. As the ONS warns in the report, Scotland and Northern Ireland are likely to face proportionally greater future demands on health services than England and Wales. This week's revelation that the cost of free personal care for the elderly has reached £440 million came with the projection that it could reach £1 billion a year within a generation. If the trend of longer periods of illness continues, those calculations could be a serious under-estimate.

Considerable research is already under way to identify the factors which cause such a marked difference between Scotland and England. The effects of lifestyle, including diet, alcohol consumption and levels of activity, and poverty are well-established. Yet studies comparing Glasgow with other de-industrialised cities with similar patterns of eating and drinking suggest there is a separate so-called Glasgow factor. It may be genetic.

Today's report that alcohol sales in Scotland have dropped by 5% over two years provides a glimmer of hope that the health message is gaining ground, although consumption remains significantly higher than in England. The effects on later life, however, will not be known for another 30 years.

Nevertheless, for any Scot, male or female, aspiring to a long and happy retirement, the message is clear: adopt a healthier lifestyle immediately or you might live just long enough to regret not changing habits.