A genetic discovery in New Zealand’s first and largest longitudinal study has found that girls and some ethnic groups have the genetic capacity to live longer lives.
It has also prompted a call for better social support for Pasifika and Māori who are not benefitting from the genetic advantage revealed in the “Growing Up in New Zealand” research.
The ongoing study saw University of Auckland researchers extract DNA from saliva samples taken from more than 4000 pre-schoolers aged between four and four-and-a-half.
The tips of the DNA strands, called telomeres, were then measured for clues about ageing.
“Telomeres are these little things at the ends of your chromosomes and they get shorter and shorter as we age,” says Caroline Walker, a molecular biologist on the project. “Their role in the cell is to protect your DNA.”
The findings revealed that young girls have significantly longer telomeres than boy and that children born to older mothers have longer telomeres.
When it comes to ethnicity, Pacific children have the longest telomeres, followed by young Asians and Māori.
“When we compared between ethnicities we found that European children had the shortest telomeres,” Walker says.
“And it was quite a considerable difference between New Zealand European children and Pacific children.”
The current scientific thinking is that longer telomeres signal the genetic potential for a longer life but that is not reflected in our Pacific and Māori populations.
“We know that over the last 15 years there's been a gap of about six or seven years between Māori and Pacific who have a lower life expectancy than non-Māori and non-Pacific people,” says Dr Corina Grey.
Dr Grey is a public health specialist who says the research highlights a strong case for improving known social determinants like housing and wages. She is also calling for more support for policies that offer benefits for a lifetime.
“Things life a sugary drinks tax,” says Dr Grey. “We know, for example, that Māori and Pacific children get a large proportion of their daily sugar consumption comes from sugary drinks.”
She says the implementation of sugar taxes overseas have worked.
Researchers say now they know Pacific and Māori children have longer telomeres at an early age, the big question is how that is going to change over their llfespan.
They may have a clearer idea when the retest the childrens’ DNA in four years' time.
About Growing Up in New Zealand:
• Growing Up in New Zealand is a University of Auckland study, managed by UniServices Limited.
• The study has been funded by the Government through the Ministry of Social Development since 2017.
• It is the country’s largest contemporary longitudinal study of child development.
• It follows more than 6000 children born in the Auckland, Counties Manukau and Waikato District Health Board areas.
• The study has followed the children from before birth and intends to continue until the children are at least 21-years-old.
• The study has been specifically designed to reflect the diverse lives of children growing-up in the cultural, economic, societal and technological complexity of 21st century New Zealand.
• It is especially focused on what works to optimise child development and resilience.
• Children and families generously give their time to the study for free, with face-to-face data collection waves taking place every two to three years.
• Find out more about Growing Up in New Zealand’s research here