With half of those million men admitting to feeling lonely and isolated, a worrying picture is emerging of a generation of males struggling to hold on to social and family ties that seem to come more naturally to women.
Where older women tend to be comfortable with participating in social groups, men seem to find it harder to join in, Help the Aged policy officer Amy Swan told AFP.
Many of these group activities are female-focused and the men who do go are outnumbered by women "which can be quite intimidating", she added.
Britain's health minister Ivan Lewis has called attention to the issue, saying care for the elderly would become "the new child care" in this century as people live longer -- but not necessarily better, with health problems such as dementia or heart disease.The last time Derek Dobbs needed to make a hospital visit, the 84-year-old British war veteran called Eileen Goodwin to come round to help -- even though they have little in common.
Dobbs' wife Corrine used to clean for Goodwin until she died 10 years ago -- but Goodwin is kind-hearted and always ready to help out.
"She takes me to hospital and to see the doctor. It would be impossible for me to get to these places if she didn't take me. And I really appreciate that," Dobbs said.
Like a growing number of elderly British men, the old soldier needs help since his wife passed away, leaving him alone in their home in the village of Lower Tuffley in Gloucestershire, western England.
The former jack-of-all-trades and manual labourer has now "got used to being on his own". His son and grandchildren do not live nearby and while they do visit occasionally: "They've got their own lives to live."
Retired engineer William Payne, 86, from Hucclecote, also in Gloucestershire, said he started going to a local gym for company after his wife died seven years ago.
"I go to the gym for a couple of hours once a week," the pensioner said. "There's usually a group of about 20 elderly people there so I find that quite sociable."
Divorce and family breakdown can be another reason for such isolation.
"This is the first wave of men coming out of the divorce-generation," Swan said. "Some of these men have experienced a family breakdown, or were not given custody rights after a divorce.
"As a result, we've found that many enter the later stages in life with difficult family relationships or weaker ties with their children."
Indeed research carried out by the charity found that grandfathers are nearly twice as likely to go up to six months without seeing their grandchildren as grandmothers.
"Men tend to have weaker social links and contact with family and friends," the charity said. They also tend to be "less comfortable with planning social interactions and knowing how to integrate themselves fully into society."
One middle-aged British man, Mike Hammond, recently put up an advert in a Hampshire post office asking for someone to befriend his 88-year-old father Jack and take him out once in a while to the local pub for a drink.
Hammond, who says he lives too far away to join his lonely father for a regular drink, offered to pay seven pounds per hour (14 dollars, 9 euros) for the service.
Research by another charity, Age Concern, found that the risk of social exclusion among the elderly increases with age.
A spokeswoman told AFP: "Many older people experience loneliness but men over the age of 80 who live alone -- as well as those who are recently bereaved -- are particularly at risk."
They also face different challenges.
Swan from Help The Aged cites the example of elderly men baffled by housework, since many came from a generation where the husband went out to work while the wife stayed home to cook and clean.
Payne admits that he struggled with the housework after his wife passed away. "I never did much around the house, mainly a bit of hoovering and washing the car. It was quite a challenge at first but I can do it all now," he says.
And Dobbs said it was only after his wife died that he realised how much work she did around the house.
"My wife, who had to go out to work because we didn't have much money, did all the washing, cooking and cleaning as well. Like all blokes do, I took that for granted. Only now do I appreciate the work she did."
For those who struggle to leave the house or whose mobility is limited, a daily telephone call can help ease loneliness. Charities like Age Concern and Help the Aged offer a service where volunteers ring some of the pensioners for a regular chat.
Dobbs gets a daily call through a Help the Aged phone service to remind him to take his medicines. He says he looks forward to when the phone rings.
"Sometimes they're very busy," he says of the volunteers, "but I'm always glad when they have time for a chat."
"I manage on my own," he concludes. "But now and then I do think: 'Wouldn't it be nice to walk into the kitchen and have a nice cup of tea waiting for me?' But, no. If I want one, I'll have to get it myself."