The number of babies receiving treatment for cow’s milk allergies has rocketed in recent years, to such an extent that it has alarmed researchers. 

“The amount of formula [for babies with a cow’s milk allergy] being prescribed is way higher than you’d expect,” says Dr Michael Perkin, consultant paediatric allergist at St George’s Hospital in London. “It’s tenfold. There’s no obvious explanation for it from a disease point of view.”

Perkin is part of a team of researchers, led by the University of Bristol, who found last week that doctors and parents could be wrongly diagnosing babies with milk allergies. The problem lies in the guidelines, which they believe are too broad.

Three-quarters of babies monitored in the study experienced two or more of the symptoms of a milk allergy before they turned one. These can include abdominal pain, reflux, constipation, diarrhoea and eczema. Because these symptoms are all common in babies, the researchers say, they can be easily mistaken for a cow’s milk allergy.   

There are two types of cow’s milk allergy – one which can be tested for and another called the ‘delay type’, which can’t. The latter has been on the rise. 

“There is a really significant hike in the number of children we’re seeing with perceived milk problems,” says Perkin. “Go to Mumsnet and a billion hits will come up for cow’s milk allergy.” 

Less than one per cent of babies have cow’s milk allergies but the numbers being diagnosed are far higher. 

“A recent promotional flyer from Nestlé said milk allergies could have risen by 25 per cent, but it was based on a survey of parental perceptions,” says Perkin. “It’s probably not the best thing to rely on parental supposition.”

The concern around babies and cow’s milk is emblematic of a growing interest in dairy, lactose, and the problems associated with them. It begs the question, have we become too quick to diagnose ourselves and our children with milk issues? 

“There’s more awareness that food can trigger symptoms,” says Lucy Jackman, a registered dietician with The Gut Health Clinic. 

Alternative milk has proliferated in recent years and it’s not uncommon to hear people say things like “dairy doesn’t agree with me”. But it’s more complicated than that. Many people confuse dairy allergies with lactose intolerance. 

“An allergy and intolerance are not the same thing and often the words are used interchangeably,” says Jackman. “An intolerance can be driven by an enzyme deficiency – when lactase isn’t present to break down the lactose. That can be temporary, like after a gastroenteritis bug, which makes it difficult to tolerate for a couple of weeks.”

Lactose is a sugar only found in animal-based milk and we require lactase to digest it. People with an intolerance don’t have lactase in their system. Some dairy products contain lactase, such as live yoghurts, while some also contain so little lactose that it doesn’t need to be broken down, for example, hard cheeses like Parmesan.    

“An allergy is driven by our immune system and has a very different mechanism to produce symptoms,” says Jackman. Someone allergic to dairy couldn’t have live yoghurt.

The results can be similar – constipation, diarrhoea, bloating – and people should visit a GP if they suspect either. 

Meanwhile, infants tend to grow out of cow’s milk allergies as they mature.  

Jackman advises people who are concerned about how lactose and dairy affect their bodies to visit their doctor. She says they shouldn’t cut food types out of their diet without a formal assessment. 

“With a delayed allergy, you have to remove it from your diet for four to six weeks then reintroduce it back into the diet to see if the same symptoms occur when it’s brought back in,” says Jackman. “A lot of people start the first part – cutting out the food – but never reintroduce it. We wouldn’t want anyone to unnecessarily remove it.” 

This is important because cow’s milk is a natural source of calcium and protein, as well as B12 and iodine. These can help with bone strength and development, which are crucial for infants and can lower the risk of fractures in older children and adults. They can also help improve the way our muscles function. Milk alternatives tend to contain lower quality protein and contain fortified nutrients such as calcium. 

Jackman adds that social media has encouraged people to cut things out of their diet that they don’t need to. “It’s important to have support from a professional to confirm a diagnosis,” she says. 

Growing interest in the dairy industry has also played a part in the overdiagnosis of milk intolerance. “Whether it’s suspicion of milk and dairy allergies and intolerance, or people’s changing attitudes about the industry is difficult to say,” says Jackman. “People aren’t just removing dairy – a lot of people also remove gluten but we would only recommend that if they’re diagnosed with Coeliac disease and have confirmed it is triggering symptoms.”