Cows' milk for the lactose intolerant: The turning pint

Millions of people who believe they are lactose intolerant could return to cows' milk, according to research into a more gut-friendly version. Kate Hilpern investigates

Glass half-full: Sebely Pal, centre, with her Curtin University researchers (Robert Duncan/WAnews)

There's a milk war going on Down Under and there are signs that our own milk industry may be entering similar combat. If the battle reaches anything like the same scale as Australia's, millions of people who believe that they are lactose intolerant could find themselves able to return to commercial milk, thanks to a so-called "A2 version" now on sale. With a staggering one in five Brits now avoiding cows' milk, believing that they are intolerant to it, that's a lot of folk.

"Originally, all cows produced milk containing only the A2 beta-type protein," explains Professor Sebely Pal, the leading researcher in nutrition at Curtin University in Perth, who led a new study that was funded by the milk producer a2 Milk. "But owing to a genetic mutation in European herds, another milk protein emerged – A1 – and spread throughout many countries. Today, milk with the A1 protein makes up the majority of milk in our fridges."

It is this A1 milk, according to her study – the world's first on humans – that can cause people discomfort, while milk that contains the A2 protein and no A1 protein is much easier on the digestive system.

Sounds more like a dream come true than a war zone. But with the study finding that even those who normally drink dairy milk could benefit from A2 milk, the potential to cause commotion in the milk industry is huge. Which is exactly what's happened in Australia, where a2 milk (capital A for the protein name; small a for the brand name) has taken the country by storm and now accounts for nearly 10 per cent of the country's fresh milk market. The company's sales increased by 24 per cent in the last year alone, with consumers reporting that it's making them feel less bloated, uncomfortable and lethargic.

As a2 milk has been available in major supermarkets in the UK since 2012, you're probably wondering why it's not flying off the shelves here already. Indeed, the company already works with 20 farms in Cheshire and North Wales to specifically select A2 cows, producing a2 milk daily.

Professor Pal believes that there are a number of reasons. First, and most crucially, there hasn't been the evidence until the Curtin study, which involved 41 men and women doing a two-week "dairy wash out", after which they consumed 750ml a day of either A1 or A2 milk. After two weeks, they had another "wash out", then swapped milks, which they drank for another two weeks. The blind trial showed that the A1 protein milk had a 61 per cent higher bloating score and 38 per cent higher abdominal pain score compared with A2, as well as a being linked to softer stool consistency. "Animal studies had previously investigated the effects of A1 vs A2, but nobody could really claim the evidence was conclusive until a human trial had been carried out," explains Professor Pal.

Secondly, unlike in New Zealand, where a2 has been available since 2004, and Australia, where it's been available since 2007, a2 hasn't been heavily marketed over here. Thirdly, even the 20 per cent of Brits who say that they react badly to commercial milk tend to assume that they are lactose intolerant, so they'd consider a2 milk to be irrelevant to them anyway. The phrases "milk intolerant" and "lactose intolerant" are often used synonymously, says Professor Pal, whereas in fact, many people react not to the lactose at all, but to the A1 protein.

Jilly Pearce knows this well. The 40-year-old from Bexleyheath, south-east London, suffered from irritable bowel syndrome for years before realising that it was at its worst just after breakfast. "Putting two and two together, I deduced that it was probably the milk in my cereal and morning tea that was causing the issues and, sure enough, when I cut down on milk, I noticed a difference very quickly. I no longer felt bloated or lethargic."

Pearce took the logical next step of cutting milk out of her diet completely, and when she continued to feel better, she put her IBS down to a lactose intolerance. "But I missed my porridge and hot drinks like mad and the likes of soya and almond milk just don't taste as nice. So one day, when I came across a2 on the supermarket shelf, I thought I'd give it a try. It tasted great, as cows' milk always does, but as it still contained lactose, I waited for the symptoms to come. But they didn't and I have to say that it's changed my life dramatically."

There are thousands of stories like this, including among children. Leia Greasby's daughter Jessica, 13, for example, was 11 when Leia realised that she had a problem with cows' milk. "She had all the typical symptoms of someone suffering an issue with cows' milk, such as bloating, cramping, diarrhoea and generally feeling low. But we hadn't spotted it before because she also had a gluten allergy, which was masking all her symptoms," explains Leia.

Jessica was apprehensive about trying an A2 milk. "For her, milk meant living on the toilet – dreadful for a teenager," says Leia. "But it's turned her life around and she's been able to eat home-made ice cream, enjoy milkshakes and even cereal, with no bloating or cramping. Six months on, she's got more energy and is growing again."

But although the Curtin study included a subset of people with self-reported intolerance to commercial milk – and it was they who reported the greatest benefits of A2 over A1 milk – the vast majority of participants did not consider themselves to be milk intolerant at all. And it is this group that has most surprised Professor Pal.

"Yes, the study is great news for the milk-intolerant because the calcium in cows' milk has key health benefits when it comes to bone health and the prevention of osteoporosis, for instance. But for me, by far the most interesting bit of the study is that the bulk of participants thought that they were milk tolerant and drink it regularly. Yet, when we looked at their gut reactions to A1 milk under the microscope, we found that they experience gut inflammation and have changes in their stool consistency that they don't get when they drink A2 milk. I think people must just get used to reacting to A1 milk, considering the symptoms normal. But our study shows that people don't have to put up with it."

Professor Pal has high hopes for future research around milk proteins. "I'd like to explore whether the different proteins in milk may be used to help prevent or treat conditions including autism, diabetes and heart disease. There's already some animal evidence around this. It's just a matter of doing a human trial. This could be huge news."

Dr Ditte Hobbs, a nutritionist and research fellow in the Hugh Sinclair Unit of Human Nutrition at the University of Reading, describes the Curtin study as "interesting, timely and much needed".

But it's only a preliminary step, she adds. "Participants consumed the milks for quite a short duration. Also, the study lacks any kind of microbiology, which is needed to find out exactly what is going in our colons. Thirdly, it's the only human study in the area and it's therefore important not to take this data as concrete evidence."

Meanwhile, the British Dietetic Association (BDA) warns that dairy intolerance is widely misunderstood. "More people than ever perceive that they are intolerant to milk, whereas in fact a very small percentage have a genuine intolerance," says Sioned Quirke, a dietician and BDA spokesperson. "I think the misperception is a lot to do with celebrities endorsing avoiding certain food groups and the growing market for self-test kits, despite them having no scientific basis. Other factors are the growing 'free from' ranges in supermarkets and the assumption that alternative, more expensive milks must be better for you. None of this is helped by the fact that there is no clear and simple test for milk intolerance."

A lot of people tell their dieticians that milk gives them constipation when further exploration reveals that they hardly eat fibre, she says. "Or they tell us that milk makes them bloated when actually we find that they have IBS. Our bowels are a complex organ and it's not always one single thing that affects them. Even the amount of physical activity one does or their fluid intake can affect how the bowels work. So whilst this study is fascinating, I wouldn't want to raise people's hopes by suggesting it is the answer to all their problems."