The latest results from a longitudinal study about Tongan migrants has found they are happier in New Zealand, but not necessarily healthier.

But Melini Taufalele, a Tongan who has called Waikato home for 25 years, did not need a survey to identify issues in the Tongan migrant community which he has been attempting to correct through volunteer work.

The Pacific Island - New Zealand Migration Study (PINZMS), which began in 2005, researched the broad effect that migration had on families and communities.

Research head Waikato University Professor John Gibson, together with post-doctoral research fellow Dr Halahingano Rohorua, had surveyed more than 500 families who applied by ballot to migrate - either successfully or otherwise.

Prof Gibson said the data was providing policy-informing insights into health consequences of migration.

"Our data shows migrating causes a significant rise in blood pressure – the incidence of hypertension goes up by more than 10 percentage points compared to the incidence among unsuccessful ballot applicants in Tonga.

"It’s likely that more salt in diets and the greater stress of living in New Zealand are behind this change."

However the mental health of participants – particularly women and those with lower levels of mental health – improved in those who migrated. 

The migrant group also said they felt "happier, more cheerful, less nervous and less downhearted".

None of the results surprised Mr Taufalele, who ‘‘was probably one of the first 20 Tongans to live in Hamilton’’ after he migrated to New Zealand in 1987.

Mr Taufalele, an electrician for Fonterra, said a lack of education, finances and understanding plus lifestyle choices were some of the barriers that prevented other Tongan migrants from being as fit, healthy and happy as he was.

Mr Taufalele and his "Kiwi" wife Isla, both Bahai, worked tactfully with migrant families to improve their understanding of healthy living in New Zealand, covering topics such as exercise and cleanliness, particularly the importance of airing out their homes to avoid dampness.

The Taufaleles, who did not drink or smoke, have also spent the past five years volunteering with Hamilton children - mostly Tongans - to improve their literacy and numeracy skills, and providing moral education classes.

"Our three boys have left home now, so we have time to give back to the community."

- © Fairfax NZ News