While dairy giant Fonterra announced last week it was introducing a regional school milk pilot scheme in Northland next year, Associate Prof Brian Cox said four approaches for research funding, including to the dairy industry, had been unsuccessful.
The school milk programme will cover 110 schools and 14,000 children and, if successful, it might be extended to a national programme by the start of 2013.
Earlier this year, Prof Cox and Dr Mary Jane Sneyd, of the Hugh Adam Cancer Epidemiology Unit, reported their findings from research into the school milk drinking habits of 562 people, aged between 30 and 69, diagnosed with bowel cancer and compared them with 571 people of similar age without the disease.
The findings suggested the risk of bowel cancer was 30% lower in people who drank school milk daily and the reduction in risk was greatest for those who drank 1200 or more of the 300ml bottles of milk in their school years.
The research was prompted by earlier research showing the incidence of bowel cancer was lower in those born from about 1938 to 1953. The previous school milk programme involved many schools over 30 years to 1967.
Prof Cox wanted to carry out two further studies to see if the original findings were supported.
"We would be most interested in studying the health effects of the reintroduction of free school milk in New Zealand.
However, as the time delay between the consumption of milk at primary school and the measurement of a change in risk of bowel cancer is long - about 40 years - we will probably not be alive to measure any effect of the reintroduction of school milk."
This meant only a retrospective approach was feasible to examine this further.
If a further retrospective study, similar to the one already completed, confirmed the original findings, "we would not need to wait for 40 years to see whether the reintroduction of school milk reduced later risk of bowel cancer".
It would then be possible to postulate a more specific approach to preventing bowel cancer, he said.
Otago and Southland have the highest incidence of colorectal cancer in the world.
• Health professionals have applauded the move to bring back free milk for school pupils.
The New Zealand College of Public Health Medicine said a "significant number" of children were living in circumstances where their nutritional needs were not being met.
The president of the college, Dr Julia Peters, said the Fonterra "milk in schools programme" was a step in the right direction.
"We applaud this move by Fonterra. It's heartening to see a major corporate supporting the health needs of the most vulnerable members of society, our children.
"It is a constructive response to recent criticism that the price of milk has put it out of reach of a lot of New Zealanders," she said.
"Simple initiatives such as this rolled out at a national level will help to promote the health and wellbeing of our children, delivering better health outcomes for future generations."
- Additional reporting APNZ
