Lactose-intolerant prefer A2 milk
People suffer less discomfort from drinking A2 milk than conventional milk, a New Zealand study has shown.
It also appears to show that it is not just the lactose in conventional milk that bothers consumers, but the A1 protein also has a detrimental effect.
Professor David CameronSmith, who oversaw the study, said the advantage of A2 milk was that consumers could receive all its nutritional benefits but not suffer drawbacks such as nausea and abdominal pain.
‘‘The primary advantages are two-fold: you can consume the natural product and there’s no digestive problem, and lactose-free milk has limited application - for example you don’t get too much in the way of lactose-free ice cream because it doesn’t taste fantastic,’’ Cameron-Smith said.
The University of Aucklandbased Liggins Institute carried out the research jointly with AgResearch.
A follow up study plans to study the full gamut of dairy products, including cheese, butter, ice-cream and yoghurt made from both A1 and A2 milk.
The a2 Milk Company, founded in New Zealand, contracts companies such as Synlait to produce fresh milk, infant formula and powder.
Study lead Dr Amber Milan said she tested 30 healthy young women between the ages of 20-30 who said they had trouble digesting milk, and a control group of 10 dairy-consuming women.
In comparisons, the lactoseintolerant women did not feel nauseous or have an urgent need to go to the toilet after drinking A2 milk, but they did after drinking conventional milk.
They were half as likely to report abdominal pain, fullness and bloating over 12 hours, although they experienced the same levels of flatulence and gastric reflux after drinking A2 and conventional milk.
AgResearch senior research scientist Matthew Barnett said there was some evidence the symptoms of lactose intolerance might be influenced by the proteins in milk.
Conventional milk contains both the A1 and A2 types of betacasein, a protein comprising 25-30 per cent of total milk protein. It’s thought that originally all cows produced only the A2 protein type, and the A1 mutation appeared 5000-10,000 years ago.
Dr Milan said animal studies showed a breakdown product of the A1 protein caused inflammation in the small intestine, which seemed to worsen lactose intolerance.
‘‘What our findings suggest is while we can’t fix the inability to digest lactose, we might be able to minimise the exacerbating action of the A1 protein.’’
Cameron-Smith said one of the messages was that there was value in diversity for a small exporting country like New Zealand.
‘‘If there is no loss in terms of genetic viability of the national herd and productivity, the more we can diversify and create a Kiwi inc story, the better that’s got to be for the country. A2 offers one avenue to create a diversified unique story, and in any sophisticated market there’s room for all players.’’
The study was funded through the Government’s High-Value Nutrition National Science Challenge, with co-funding from the a2 Milk Company.
It was the first in the world to compare people’s immediate digestive response to conventional milk and A2 milk, and the first to compare lactose-intolerant, dairyintolerant and milk-tolerant people.It was the first in the world to compare people’s digestive response to conventional milk and A2 milk.