The Age UK poll of 2,000 over-65s found 10% described themselves as often or always lonely – a rise from 7% a year ago.
Four in 10 said their TV or pet was their main form of company.
Research has shown loneliness increases the risk of ill-health and early death, prompting ministers to call on people to look out for people at risk of loneliness in their communities.
“Devastating impact”
The poll randomly selected and then interviewed people aged over 65 according to their gender, working status and the presence of children, said Age UK.
Last winter, the ‘Friends’ campaign appealed for a return to an “old-fashioned sense of neighbourliness” by encouraging people to check on elderly friends and neighbours.
Living alone is linked to habits that are bad for health. For example, eating poorly and having less motivation to be physically active can be a consequence of being physically isolated.
Being alone can also affect mental health, causing people to feel low and depressed.
However, feeling lonely can in itself be bad for your physical health. Studies have shown that social isolation can cause damage to the immune system leading to a condition called chronic inflammation.
Announcing the move, Jeremy Hunt said it was a source of “national shame” that loneliness was emerging as such a problem.
Caroline Abrahams, of Age UK, said loneliness can have a “devastating impact”.
She said: “Loneliness not only makes life miserable for older people. It is also really bad for their health making them more vulnerable to illness and disease.”
Research has shown that the ageing population has led to an increase in people living on their own.
But Ms Abrahams said cuts to local services, such as lunch clubs and day centres, had exacerbated the problem.
Source BBC News