The country’s largest longitudinal study has found that girls, Pacific children and children born to older mothers have a unique genetic advantage that could potentially help them live longer.

The discovery was made during analysis of DNA samples from children in the Growing Up in New Zealand study, which has been tracking more than 6,000 children since birth.  

The University of Auckland study examined the DNA of more than 4,000 children to record the length of telomeres, an essential part of all human chromosomes.  

Telomeres are like the plastic tips on the end of shoelaces – they protect each strand of DNA from damage. Telomeres shorten as we age and can affect the development of age-related disease.  

Growing Up in New Zealand molecular biologist and senior research fellow, Dr Caroline Walker, says the study is the first to examine telomere length in New Zealand children.  

“This is an important study because it’s the first time we’ve gathered information in children of this age which gives us vital genetic clues about how the next generation of New Zealanders might age,” Dr Walker says.

The study used a special technique to measure the length of telomeres and discovered:  

• Girls had significantly longer telomeres than boys.
• Pacific children had the longest telomeres, followed by Asian children, Māori children and then European children.  
• Children born to older mothers had longer telomeres.  

The study is the first to show differences in telomere length between ethnic groups in New Zealand children.  

Dr Walker says the study found that Pacific and Māori children had longer telomeres - a sign of potential longevity, but in reality, these two groups have a lower life expectancy on average compared with European New Zealanders.  

“More research is needed to understand how telomere length interacts with other genetic and environmental factors to affect the health and wellbeing of Māori and Pacific peoples,” Dr Walker says.  “We certainly know that stressful or adverse environments can impact the length of telomeres in later life.”

“The beauty of a longitudinal study like Growing Up in New Zealand is that it means we can potentially track how the length of telomeres change over time to understand the influence of certain environmental factors, such as stress, diet and exercise,” Dr Walker says.

The research on telomeres was published in the journal Scientific Reports. You can read the full paper here.