A2 milk offers hope for lactose intolerant
Though few people go to the trouble to getting a clinical diagnosis, around one in five believe they are lactose intolerant.
For those who roll their eyes at anybody jumping on the lactose intolerance "fad" without seeing a doctor first, have a little compassion for the painful symptoms those 20 per cent of people face when they drink milk, eat ice cream, or consume a bit too much cheese.
Within an hour or so, most self-reported lactose intolerant people experience stomach cramps, bloating, and gassiness, and some will have swift, unexpected, and explosive bowel movements.
A lot of lactose intolerant people have switched to soy, rice, almond, and other milk alternatives; much to the joy of their insides. According to some milk producers, however, there is an option for these people to go back to regular dairy. It's called "A2 milk".
Milk contains proteins called beta-caseins. Traditional cow's milk contains both A1 and A2 beta-caseins, but A2 milk contains just the A2 protein. The protein make-up of cows milk is genetic and naturally-occurring: In essence, different cows produce different variations, and the majority of cows are just bred to contain both beta-caseins.
A2 milk is from cows bred specifically without that A1 protein. This isn't genetic modification, rather a process of selective breeding. Once upon a time, all milk is thought to be from A2 cows, but now after centuries of DNA mutations, the majority of the world's cows produce the A1 variant.
This is pertinent to the A2 milk debate for lactose intolerant people because it's suggested their bodies react negatively not to dairy as a whole, but just to the A1 protein beta-casein within it. Take out that protein, A2 milk producers say, and you might remove all those nasty, bloaty, gassy symptoms that come with drinking milk.
But is any of this confirmed by science?
In 2014, a peer-reviewed, "double blind", randomised human trial on A2 milk was conducted in Australia, where the A2 milk industry is burgeoning. From Perth's Curtin University, the study found that A1 milk gave people 61 per cent more bloating and 38 per cent more abdominal cramps than A2 milk.
However, that study was labelled by some mainstream (ie. A1) milk producers as too small and too inconclusive to offer proof of A2 milk's benefits to lactose intolerant people.
Another study led by professor Sun Jianqin, of Hua Dong Hospital in Shanghai, China, was published in Nutrition Journal last year and found similar results to the Perth study: Milk containing both types of beta-casein was associated with significantly greater symptoms of "post-dairy discomfort", known as PD3.
For now, that's it for major studies on A2 milk and its relation to lactose intolerance, giving some good insight – but leaving much to be desired.
The A2 milk brand "a2" has been available in New Zealand since 2003. The company developed a DNA test to identify the A2 protein, and found it was still present in "old world" cows in Asia and Africa, plus some breeds such as Jersey and Guernsey cows. a2, then known as the A2 Corporation, urged Kiwi dairy farmers to undertake breeding programmes with A2 cows, but this was met with much hostility by Fonterra.
Some dairy farmers did get on board and today a2 holds a tiny market share in New Zealand. It does, however, represent almost 10 per cent of milk sales in Australia and this market is growing annually.
While A2 milk may indeed be effective at curtailing PD3, sufferers, as noted, do not necessarily have a lactose intolerance. A2 milk still contains lactose; what's omitted from A2 is actually the protein fragment "beta-casomorphin- 7" (BCM7). BCM7 slows down digestion and allows for longer periods of lactose fermentation in the gut.
Given that most lactose intolerance is self-reported and not clinically-diagnosed – in fact there's no clear or easy test for lactose intolerance – some of that "intolerant" 20 per cent of people may just be more affected by BCM7 than the other 80 per cent (those unaffected by lactose consumption).
A2 milk is more expensive than the traditional variety (about $4.90 for 2 litres), but for most sufferers, that's not too prohibitive for a few weeks' trial.
Certainly cheaper than the same volume of almond milk, it might well be the solution the perennially post-dairy discomforted have been looking for.