You might be forgiven for thinking dairy intolerance is a fad or a myth, part of the trend towards clean eating, given how widespread it seems to be. So, the truth may be surprising. Far from being a new issue, concerns over our ability to drink cow’s milk are probably millennia old.
Mankind’s ability to digest milk has gone hand in hand with our success as a species. While in some parts of the world, such as China, the majority of people are lactose-intolerant, this number falls to just 5 per cent in the UK. Scientists believe that it was an evolutionary advantage for our European ancestors to digest milk, making them able to get the nutrition they needed in times of famine.
As with all evolutionary progress, what began as a genetic mutation led to becoming a strength, and early European humans adopted dairy farming at least 7,000 years ago. The nutritional benefits that it brought undoubtedly played a key part in their survival.
An intolerance to dairy is not the same as a cow’s milk protein allergy, which is much rarer and typically causes a fast reaction with symptoms including hives, swelling, vomiting, wheezing and, at its worst, anaphylaxis.
But in addition to that small percentage of Britons who are lacking the necessary enzyme (lactase) in the small intestines to break down the lactose, there are many more who still report symptoms that are unpleasant and gut-related, such as wind, bloating, and alternating diarrhoea and constipation.
In fact, up to 20 per cent of us report that they struggle with digestion issues after drinking cow’s milk. Furthermore, it can also be a factor in triggering symptoms of irritable bowel syndrome.
Yet new research has found that for some, the issue is not related to digesting lactose at all but rather a type of protein in the milk called beta-casein. There are two types of beta-casein: A1 and A2, both found in cow’s milk produced by European breeds of cow, including the familiar black-and-white cows (Holstein Friesian) which produce most of Europe’s dairy.
Some cows produce the A1 protein, and others the A2 protein. They are all very normal cows, not even a dairy farmer could tell them apart, and indeed only a genetic test involving a cow’s hair can tell one from the other. But scientists have discovered that the natural milk they both produce can have very different effects on people.
While no one seems to have a problem with digesting the A2 protein, an intolerance to the A1 protein can cause the same unpleasant gastric symptoms associated with lactose intolerance. Research has shown that this could be because when the A1 protein is present, it reduces the activity of the lactase enzyme which is needed to digest the lactose.
So if you suffer from post-dairy symptoms, should you forget about drinking milk? Not necessarily. Cow’s milk is the most efficient way of delivering and absorbing many key nutrients in the diet such as calcium, protein, iodine and B vitamins, including the vital B12 vitamin that’s difficult to find elsewhere. Life without milk might sound fashionable, but it comes with a nutritional cost.
Alternatively, some GPs are suggesting their patients swap ordinary milk for a2 Milk, which is free of the A1 protein, as a trial. Rick Miller, registered dietitian and nutrition manager of the a2 Milk Company, says: “a2 Milk has all the benefits of cow’s milk but won’t leave you feeling uncomfortable afterwards if you struggle to digest regular cow’s milk.” This is good news for dairy lovers, who may not have to abandon milk after all.
Not all milk is the same
a2 Milk is real cow’s milk that’s naturally easy to digest.
Switching to a2 Milk has helped people who have previously had difficulty with traditional cow’s milk.
Find out more about how a2 Milk can help with the symptoms of IBS and other adverse reactions to traditional cow’s milk.