Why Is Everyone I Know Lactose Intolerant All Of A Sudden?

‘It must be something they’re putting in milk,’ I joked, as yet another relative told me they were lactose intolerant.

I didn’t really believe this theory, but it did surprise me just how many people I knew seemed to be struggling with milk digestion, seemingly out of the blue.

In my early twenties, I knew of perhaps one or two people who were lactose intolerant – where the body can’t digest lactose, a type of sugar found in milk and dairy products.

Fast-forward to my mid-thirties and it’s impacting most people I know (myself included). People who could previously glug a glass of milk or eat ice cream and yoghurt with no issues are now facing (often bowel-centred) repercussions.

If you have also noticed more people around you seem to be struggling to digest milk, there’s a fairly simple explanation behind it: ageing.

Dr Andrew Moore, a gastroenterologist at Endeavor Health, tells me: “Lactose intolerance is a very common condition and becomes more prevalent as people age, with nearly 70% of the world’s population being affected by some estimates.”

As we get older, the body starts making less and less lactase, the enzyme needed to break down lactose, which is typically found in animal-based milk, yoghurt, cheese, butter, ice cream and cream

“When there is an excess amount of lactose that cannot be broken down, that’s when you start to experience symptoms,” Dr Moore continued.

Race and ethnicity can also heavily impact the likelihood of you struggling. Dr Moore notes lactose intolerance can impact 90% or more of East Asians, while for people of European descent it’s thought to impact between 15-25% of people. (This is because a large number of Caucasians have a gene that enables them to produce lactase into adulthood.)

Symptoms of lactose intolerance, per the NHS, can include stomach discomfort (pain or cramping), bloating, gas, a rumbling or gurgling stomach, diarrhoea or constipation, and nausea or being sick.

These symptoms can occur within minutes to several hours after eating something containing lactose, and the severity can depend on how much lactose has been consumed and your tolerance.

Dr Safa Al-Musawi, an NHS doctor, radiology registrar at Imperial College Healthcare NHS Trust and co-founder at MediWord, said the symptoms can be quite subtle at first, “which is one reason people may not immediately associate their symptoms with dairy”.

“Someone might experience occasional bloating or stomach discomfort and attribute it to stress, IBS [irritable bowel syndrome], their menstrual cycle or simply having eaten too much before eventually noticing a consistent pattern after consuming dairy,” she said.

Ageing is clearly a major factor in why I’m hearing from so many more people impacted by it, but Dr Moore notes he’s also seeing more people being diagnosed as lactose intolerant.

“This is not necessarily because the number of people with lactose intolerance is increasing,” he said, “it’s more to do with public awareness and patients being more likely to seek help for GI [gastrointestinal] symptoms.

“Additionally, there is a large variety of lactose-free products available now, which has also likely helped with public awareness.”

Dr Al-Musawi agrees that increased awareness is likely behind the rise.

“More people are now recognising digestive symptoms and seeking medical advice rather than simply assuming they have a sensitive stomach or cutting dairy out themselves,” she said. “This can make lactose intolerance appear more prevalent, even though the underlying biological process is not new.”

She added that there is also an issue called secondary lactose intolerance, which occurs when the lining of the small intestine is damaged or inflamed.

“Gastrointestinal infections and conditions such as coeliac disease or inflammatory bowel disease can temporarily reduce lactase production. In these cases, lactose tolerance can sometimes improve once the underlying condition has been treated,” she added.

Keep a food diary and note which foods you consume and the symptoms you experience afterwards. It’s also important to book an appointment to speak to your GP, “as there are numerous other conditions that can cause these symptoms,” said Dr Moore.

Irritable bowel syndrome (IBS), coeliac disease and several other gastrointestinal conditions can cause similar symptoms, so symptoms shouldn’t be self-diagnosed.

Usually, to confirm the diagnosis, you’ll need to avoid lactose-containing products and see if symptoms improve.

A GP might also suggest blood tests or a hydrogen breath test to measure how well you digest lactose. If your symptoms don’t improve, you might need to have a gastroscopy to take, and test, cells from the small intestine.

“If symptoms are severe, persistent or accompanied by unexplained weight loss, blood in the stool or significant changes in bowel habits, medical advice is particularly important rather than simply experimenting with dietary restrictions,” added Dr Al-Musawi.

“Reassuringly, being lactose intolerant doesn’t mean having to give up dairy altogether, as there are numerous lactose-free dairy options available now,” said Dr Moore.

“You will need to research which dairy products contain lactose and which products do not.”

Milk and foods such as cream, ice cream and some soft cheeses (like ricotta or mozzarella) tend to contain more lactose, notes Dr Al-Musawi.

In contrast, hard, aged cheeses (like cheddar, parmesan, or Swiss) generally contain much less lactose and are often “better tolerated”.

“Some yoghurts can also be easier to digest because of the cultures involved in their production,” she added.

“The important thing is that lactose intolerance isn’t necessarily an all-or-nothing condition. Many people can tolerate a certain amount of lactose, so identifying an individual’s threshold can be much more useful than simply deciding that all dairy products are off limits.”

Some people might also find over-the-counter lactase enzyme tablets useful when they want to eat a meal containing dairy. This helps break down lactose for you.

Dr Al-Musawi ended: “If someone significantly reduces or removes dairy from their diet, they should also think about calcium, vitamin D and other nutrients that dairy products can provide. Fortified plant-based milks and other calcium-rich foods can help fill that gap, and a dietitian can provide personalised advice where needed.

“Ultimately, lactose intolerance is usually very manageable. The goal isn’t necessarily to avoid dairy forever but to understand your own tolerance, identify the foods that trigger symptoms and make sensible adjustments without unnecessarily restricting your diet.”