Sometimes I wonder what happened to the old man at the supermarket.

He was an embarrassment to himself, to the staff and to shoppers. What was he doing? He was packing people's shopping, the way charity fund-raisers often do at the check-out, and chatting while he did it.

His behaviour was harmless at worst and helpful at best but it couldn't be allowed. It broke the unwritten rules of supermarket behaviour. The check-out assistant asked him to stop. "You can't do that," she said. She stared at him. The people in the queue stared at him. I stared at him. It was awkward, odd. He wasn't conforming.

"What am I supposed to do?" he asked. "When I go home and shut the door I won't speak to a soul until I come shopping the next time."

It was heartbreaking. He was a tall man in his late seventies. How had he arrived at this place? What had his job been? Did he have family scattered somewhere? Had there been a wife? How was he now so isolated that the supermarket was his only point of contact with the world?

I can be in and out with a week's shopping having uttered only the words, "no thanks" to the offer of bags and "thanks" for my receipt. If that was my social life how long would it take me to go mad?

I could have bought the old fellow a cup of tea. I thought afterwards it's what I should have done. The other people in the queue probably thought so too - and the check-out girl. But at the time, caught off guard, we gave him the silent stare that is reserved for those who are best avoided. We didn't "get involved".

And so I am left with his cry of despair, "What am I to do?"

We'll all soon have trouble shutting our ears to it. A report by the International Longevity Centre is predicting a rise of 65 per cent in the number of elderly men living alone by 2030. A tsunami of isolation and loneliness is on its way.

It has started already. According to the most recent findings, more than one million older men across the UK experienced moderate to high social isolation. About 700,000 reported a high degree of loneliness.

It's easy to see why. One-quarter of elderly men who live alone hear from their children less than once a month. One-fifth have less than monthly contact with friends. Mostly, that was the wife's arena. She was the gateway to family and friends. It probably worked seamlessly until she died.

In some cases, it wasn't death but divorce. "Silver" divorce rates are rising among the over 60s, often triggered by retirement. All-day proximity proves too much for some marriages to bear. Increased life expectancy means people still have one or more decades ahead. Thousands, armed with decent pensions, make a bid for freedom. Regardless of the cause of men being alone, the upshot is loneliness for many. It is a brute of a condition that creeps up on its victims. The cure is to get out and make contact with other people but loneliness robs the sufferer of the confidence to do so. They feel rejected and as if they are not worth knowing. They cease to eat well, may drink too much. They get depressed.

There is an increased risk of dementia and a measurable death risk. In fact isolation and loneliness are as bad for our health as smoking 15 cigarettes a day. It's worse for us than obesity. And what a horrible fate, to die feeling unwanted. These predictions should be a wake-up call. For years we have been focused on the rights of women and the care of women. Has the time come to turn the spotlight on to men? If we do that now might we mop up some of the current misery and avert what lies in store?

Just as we all make financial plans for old age, the report by the International Longevity Centre suggests that employers hand out a pre-retirement pack that flags up the need to retain and strengthen social bonds.

There are clubs for the elderly but we need to ask how many of them cater well for men? It's a gross generalisation but most women enjoy sitting and chatting over a cup of tea. Many men don't. They want to be doing something.

What they need are activities that cater to their interests - preferably ones that involve them in decision making. To this end, Age Scotland supports Men's Sheds, an initiative that started in Australia and is going global. The sheds provide a workshop with tools where men can gather to make things.

The men organise and run the shed according to the needs of their group. Some focus on woodwork and joinery while others do bicycle repair or furniture mending. Skills are put to use and the community benefits. There are 11 up and running in Scotland with a further 16 in the making.

The Shed offers companionship, an opportunity to be creative, to develop new skills and to get involved in the organisation.

This aspect is important because, following retirement, men can feel a loss of status as well as a diminished income. They can lose their sense of purpose. In the shed they find a new community, shared interests and fresh challenges.

Age Scotland also runs Silver Line Scotland where older people can ring up for a friendly chat when they feel isolated. And the charity is organising "walking football" to offer people with limited mobility a chance to join a team and stay in shape.

In England, the Royal Voluntary Service has teamed up with rugby clubs to help isolated old men. The clubs encourage supporters to give an hour a week to befriend an older man, maybe by offering a chat over a pint. The clubs then invited older men from their local area to attend a match with their volunteer. It is simple stuff but it is the stuff of life. It's not costly but it is cost effective. It improves health and, just as importantly it spares people from living lives of needless misery.

The sight of an elderly man living alone and lonely begs the question of where his children are.

In The Herald today, we can read Sir Chris Hoy's tribute to his father. He drove him across the country week after week and year after year to help him follow his passion for cycling. His words suggest that if and when his father needs help, Hoy will be there for him.

Not every family has such good will. Not every grown up child has the wherewithall to help.

They may live at a distance and be enslaved to a career.

Besides, how many men would choose their child's spare bedroom or duty visits above an independent and fulfilled life of their own?

On holiday I look at old men playing boules in French villages, or sitting in pairs at a corner cafe with a small glass of something dark and a chess board and I think they've got it right.

They're out of the fray but still part of the world, still connected. Men here can be connected too. They need to be consulted, to have their needs identified and met. But first they need us to focus on them; to see their plight and to winkle them out of their isolation.

Silver Line Scotland welcomes calls from any older person who feels alone and would like a chat. The number is 0800 4 70 80 90.