"There are 160,000 people over 65 who live alone," he said.
"About 10 per cent or more of those people appear to be chronically lonely, and the evidence from various health surveys suggest that in itself is a serious health risk. It's a bit like smoking 15 cigarettes a day or drinking to excess."
Silver Line, modelled on a service of the same name in Britain, will use mainly volunteers to provide a listening ear for older people.
"Many people ring up a helpline of this type without really knowing what their problem is. You have to tease them out," said Lepper.
The trust is also seeking $4 million to $5 million a year from government and commercial sponsors to pay supervision and telecommunication costs, and hopes to launch next year.
Rural Contractors NZ chief executive Roger Parton, also a trustee, said loneliness was a major problem for older people in rural areas.
"Every dollar spent in running an operation like this has a $2-$3 return in reducing the numbers of elderly requiring health support," he said.
Another trustee, AUT occupational therapist Dr Valerie Wright-St Clair, has just published a study of loneliness among elderly Asian immigrants such as the Patels. She found they desperately wanted to contribute to their new country, but often felt shut out by language and sometimes by discriminatory attitudes.
"One of the things that we hadn't expected to find was how committed each of the people was in those communities to contributing to the greater society," she said.
For the Patels, the breakthrough came two years after they arrived here when they heard about Bhartiya Samaj (literally "All India"), a support group which runs fortnightly activities for the elderly at the Mt Roskill War Memorial Hall
"We dance together, we play together, they can go with us on outings, they sometimes run exercises, sometimes Indian Bollywood evenings," said Sadguna, 63, a former teacher.
Former civil servant Madhulal, 66, said the couple enjoyed each fortnightly outing so much that as soon as they got home they started counting down the days to the next one.
They also look after their four grandchildren aged 7 to 17, taking them to festivals at the Hindu temple in Balmoral and ensuring that they speak the family's Gujarati language.
"We force them to speak Gujarati in the home, otherwise they will forget it," Madhulal said. "But they are Kiwis - they were born here."