Is lactose intolerance a myth?

Anna Magee

A staggering one in five people believe they are dairy intolerant. But new research is showing they may be reacting to a protein in milk, not lactose. Good news is, a new type of real cows’ milk may not cause any digestive symptoms at all.

‘I cut out dairy and all my bloating and wind and tummy pain disappeared.’ It’s a common utterance from people with digestive issues. The next step is often the same – they assume the problem is lactose intolerance, give up cows’ milk and join the one in five people who believe they can’t drink milk. Non-dairy milk alternatives are so popular now, they have been added to ‘the basket’ for the first time – an annual measure of UK inflation. According to the Office for National Statistics, this reflects a growing trend of dairy-free diets, with encouragement driven by campaigns such as Veganuary.

MORE: How to go vegan – lessons our writer learned after doing Veganuary PLUS best vegan cookbooks


20 per cent of adults say they don’t get on with cows’ milk, suffering from digestive issues, bloating and skin problems

Reports show that 20 per cent of adults say they don’t get on with cows’ milk, suffering from digestive issues, bloating and skin problems. ‘As a result people are turning to artificially modified or plant-based alternatives,’ says Rick Miller, a leading registered dietitian.

More and more of us are looking to plant-based milk alternatives

But, according to Miller, compelling scientific research suggests people may not be reacting to lactose, but to a protein found in milk called A1.

‘As cows’ milk protein allergy can be diagnosed relatively easily and doesn’t tend to last into adulthood, the traditional view is that people with continued problems with milk are lactose intolerant.’

‘There are two major proteins in milk, whey and casein. Within the latter, there are two subtypes called A1 and A2. These are natural genetic variants that occur in cows’ milk.’

While human breast milk, goat’s milk, sheep’s milk and all other mammalian milks only contain A2 type protein; the A1 protein seems to be only found in European dairy cows

‘While human breast milk, goat’s milk, sheep’s milk and all other mammalian milks only contain A2 type protein; the A1 protein seems to be only found in European dairy cows,’ says Miller.  ‘It is thought that A1 appeared approximately 5000 years ago; and this happened to be in conjunction with the start of intensive dairy farming. However, if you travel to places such as Africa and India, the local cows only produce A2 protein in their milks.’

If you drink cow’s milk, you’re probably getting the A1 protein

‘If you drink regular cows’ milk, chances are you are consuming some A1 protein.’

Miller explains the A1 protein may be responsible for the symptoms we associate with lactose intolerance, from bloating to constipation and skin problems such as eczema.

If you’re not familiar with it yet, a2 Milk is a new milk on the block which comes from cows that only produce the A2 protein. It has been shown to cause none of the digestive discomfort, constipation or bloating that regular A1 protein containing cows’ milk can lead to.

Research from China – where reportedly up to 90 per cent of the population cannot drink cows’ milk – shows it may be tolerable to those who think they can’t drink milk.

The study, published in the Nutrition Journal in April last year, took 45 people from Shanghai, which has some of the highest prevalence of milk intolerance and gave half a2 Milk and the other half regular cows’ milk for two weeks, without telling anyone which they were drinking. They consumed no other dairy products at this time.

‘All the participants in the study reported they didn’t drink cows’ milk because they had milk intolerance and 23 of the 45 were confirmed as lactose intolerant with further testing’ explains Miller.  ‘All of those who drank the A1-containing cows’ milk reported issues such as bloating and stomach pain but those who drank a2 Milk had no symptoms whatsoever.’

In the study, people drinking the a2 milk didn’t show the same IBS symptoms as those drinking regular milk

Moreover, the study subjects were also given a ‘smart pill’ to swallow, a tiny camera that photographed the gut for issues such as inflammation, they also measured for inflammation in the blood. Those drinking a2 Milk showed no signs of inflammation while those drinking the A1-containing cows’ milk did.

They also looked at how long it took for that pill to pass through the body, in order to measure ‘gut transit time’ of the two milks – this showed what effect the milk is having on their digestion time. Those drinking A1-containing cows’ milk took 6.6 hours longer than those drinking a2 Milk. ‘This indicates that if regular cows’ milk causes constipation issues, a2 Milk is far less likely to do this’ Miller asserts.

Those drinking a2 Milk showed no signs of inflammation while those drinking the A1-containing cows’ milk did.

More recently Dr Anthony Hobson, Clinical Director at The Functional Gut Clinic in Harley Street, conducted his own trial on 12 patients with Irritable Bowel Syndrome (IBS) to see if their symptoms might improve with a2 Milk.  After an overnight fast, six were randomly assigned either A1-containing cows’ milk or a2 Milk.  Those on the A1-containing cows’ milk described an increase in their typical symptoms such as bloating and abdominal pain. Those drinking the a2 Milk™ reported mild or no symptoms at all.

The British Dietetic Association acknowledges this difference in cows’ milk within its guidelines on IBS. ‘The latest IBS guidelines acknowledge that there are differences in digestion with A1 and A2-containing milks’ continues Rick Miller. The BDA suggested that more research is definitely welcomed. ‘People with IBS who think their problem is down to milk intolerance may see a difference in their symptoms if they try a2 Milk instead of regular cow’s milk,’ adds Miller.

People with IBS symptoms such as tummy pain who avoid milk may be intolerant to the A1 protein in it, not the lactose

Julie Thompson, registered dietitian with the British Dietetic Association and co-author of the new IBS guidelines said ‘this is a progressive time for research into the condition of IBS, and the growing evidence around the A1/A2 beta-casein proteins and their impact on digestion was deemed important enough to include in the discussion of the BDA’s recent report. Some people with IBS still report problems on consumption of lactose free milk, suggesting it could be a reaction to the A1 beta-casein protein in this group of individuals. We welcome further research into this topic, specifically in IBS.’

‘Increasingly, this research is showing that there are many people who may have been misdiagnosed and labelled as lactose intolerant, when in fact, they could simply switch to a new type of cows’ milk and see if their symptoms disappear,’ says Miller

a2 Milk is available in the milk section of most supermarkets for £1.39 per litre – we tested it – and it tastes exactly the same as regular cows’ milk!

MORE: The new probiotic pill proven to help IBS

MORE: Is this the diet to end IBS?

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