Charity Contact the Elderly says around 2m people aged over 75 live alone - one for every postcode in the UK - and are at risk of social isolation.
Isolated elderly patients can often end up visiting their GP practice unnecessarily because of loneliness, adding to pressure on practices already facing soaring demand, the charity says.
But the charity has set up a network that runs tea parties on Sundays for elderly people across the UK, and feedback from those who took part shows that one in four visited their GP practice less as a result.
Four GP practices have set up their own groups, and the charity is keen for more practices to take similar action or to refer patients to existing groups.
'Loneliness among older people is a problem that can easily be solved by a community,' said Contact the Elderly chief executive Mary Rance.
'Quite often, a GP visit can be the only contact a socially isolated person has with the outside world. Therefore, we wanted to create something that could be given to patients to offer assistance in a discreet but significant way. We hope GPs will give our invitations to patients of concern, or simply pop them up on their waiting room noticeboard.
'We know that loneliness often results in increased GP visits, so we are proud to offer a solution that not only helps the patient, but decreases the pressure on GP surgeries.'