A third of people in their 50s or above, and almost half of those over 80, suffer from feelings of loneliness, a study has found.
Women were also more likely to experience loneliness than men, the report released by the Office for National Statistics (ONS) found.
Laura Ferguson, director of the Campaign to End Loneliness, said the condition was more dangerous than many imagined.
She said: “Physically, being lonely is the equivalent of smoking 15 cigarettes a day in terms of causes of early death.”
Isolation can also contribute to depression and Alzheimer’s, she added.
Ms Ferguson went on: “Situations like becoming widowed or bereaved can contribute to feeling lonely, especially at a time when you’re reaching an older age, like 80-plus.
“You might be losing mobility and losing people around you.”
The figures showed some 39 per cent of women aged 52 and over said they sometimes or often felt lonely compared to 27 per cent of men, the English Longitudinal Study of Ageing showed.