TV presenter Esther Rantzen has called on society to do more to value older people.
The broadcaster said she discovered what it was like to feel lonely when she moved into a flat following the death of her husband, documentary maker Desmond Wilcox, in 2000.
Rantzen, 73, who is launching a helpline for older people, The Silver Line, told the Radio Times that loneliness was "the most terrible poverty of all".
"Something must be done to assure our older population that they are valued," she said.
"We must reach out to them, link them back into their communities, and convince them that older people are a resource, a national treasure."
More top news
Planets outside our solar system could have earth-like oceans, evidence suggests. Could it mean a higher chance of extra-terrestrial life?
Prince Harry has waved goodbye to the people of Australia after a one-month attachment - meaning he will soon be united with his new niece.
Nearly a quarter of children in the UK under the age of five are overweight or obese, according to researchers.