Migrants from Asia are among the healthiest people in the country as they begin their new lives in New Zealand - but after several years their health starts declining, says a researcher.
Dr Samson Tse says the fact that most migrants must clear health tests means New Zealand receives those
in the best of health. He calls this "the selection effect".
They arrive "healthy and wealthy", with a lower prevalence of chronic disease than the general New Zealand population, says Dr Tse, a member of the University of Auckland's Faculty of Medical and Health Sciences.
However, his research is indicating that the longer migrants live in New Zealand, the poorer their health becomes: "The diminishing health is statistically significant."
For example, Indians as a group develop obesity, diabetes and cardiovascular problems at rates greater than the general population. South Asians - people from countries such as Bangladesh, Pakistan, Sri Lanka - have an increased prevalence of diabetes compared with Kiwis, he says.
The reasons behind the post-arrival health slump are unclear, says Dr Tse, and research is needed.
"Some possible reasons would be a change in diet or that people have limited knowledge of the facilities available in New Zealand."
Some clues have come from research last year by Robert Scragg and Alokananda Maitra, who investigated data from the 2002-03 New Zealand Health Survey. It showed that people with chronic illness were not seeking treatment. Asian women were not having mammography or cervical screening tests to the same degree as other groups, for reasons which also remain unclear.
One remedy, says Dr Tse, would be good health practice campaigns targeting individual Asian communities: "I always say, today's investment is tomorrow's saving."
According to the 2001 Census, more than 32 per cent of Asian people in New Zealand had immigrated within the past five years.
Just 5 per cent had been in the country for 20 years or more. Of New Zealand's ethnic communities, Chinese make up the largest group (44 per cent), followed by South Asian (29 per cent), Southeast Asian (13 per cent), Korean (8 per cent) and others (6 per cent).
