I grew up on milk tea. Strong, sweet, made just right. It was the kind of thing you didn’t think twice about because it was a part of your morning and evening rituals for as long as you could remember. Coffee was no different. My mother would force me to drink an entire glass of hot milk before I hopped on my school bus.
Then, somewhere in my late twenties, my body decided it had had enough.
It didn’t happen all at once. First, it was a heaviness after my usual cup, a dull ache I brushed off as ‘something I ate’. Then the ache turned into cramps. Then I doubled over, clutching my stomach, lying very still because moving made it worse. I remember staring at a half-finished cup of tea, waiting for the pain to pass, wondering what I had done to deserve this. Maybe the milk was stale? But I’d checked the expiry date.
It got to the point where even a splash of milk in my cup of chai or coffee would set my gut off. It wasn’t just the physical discomfort. It was the longing. I missed my coffee. I missed my tea. I tried oat and almond milk. I didn’t like either because they tasted like compromises, not comfort.
For a long time, I thought I was the only one dealing with this. Turns out, I am far from alone.
‘It was unfathomable that milk could be the problem’
Subhranil Sengupta, 31, an assistant account manager, remembers the exact moment his relationship with milk changed. It was the summer of 2014, after a football match, when his usual cold coffee left him with a severe stomach ache two hours later.
“I did not pay heed to it,” he recalls. But it kept happening—nausea, bloating, heartburn, every time he had anything made of milk.
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His doctor suggested a simple experiment: have black coffee after a match, then a chocolate shake with milk the next day. The black coffee was fine. The milkshake wasn’t. “So it was evident that it was the milk that was triggering the pain and discomfort,” he says.
It took him nearly two months to seek medical help because, as he puts it, the idea that milk, something he’d had since childhood, could suddenly be the culprit was “unfathomable”.
Shreya Das, 29, from Kolkata, traces her symptoms to a few months after the third wave of COVID-19. Milk tea and dairy began causing bloating, cramps, acidity and occasional diarrhoea. She switched to ginger-honey tea and oat milk and became, in her words, “more mindful while eating out”. She has since heard that many people developed new intolerances in the post-COVID period and believes it’s “an area worth paying attention to”.
For Aishwarya Ganesh, 30, from Chennai, the reaction was far more frightening. At a family dinner, prawn dumplings, a dish she had eaten all her life, made her throat tighten and her face swell. “There was no family history. I had no frame of reference,” she recalls.
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It took antihistamines and a pharmacy run to get through that night, and a second, worse reaction at a wedding requiring IV medication before she accepted that shellfish was now dangerous for her. “The doctors told me there’s no clear ‘why’ behind adult-onset allergies,” she says.
From gluten to walnuts
Others describe subtler but equally disruptive shifts. Vrushali Wani, 27, began waking up with rashes so painful they interrupted her sleep, eventually diagnosed via skin prick test as a gluten allergy alongside sensitivities to dozens of other foods. Immunotherapy over two years helped, but managing a gluten-heavy Indian diet, she says, “isn’t easy,” and gluten-free alternatives remain “significantly more expensive”.
Arshia Bhandari, 44, developed painful mouth ulcers every time she ate nuts, especially walnuts, and found relief only through homoeopathic treatment—though she admits she was never able to pin down the exact cause. Aflah ul Haque, 33, spent mornings with unexplained stomach aches before realising, through elimination, that milk was to blame. “Food intolerances are often dismissed,” he says. “People tend to assume you’re simply being picky.”
The common thread across all these stories isn’t just the food; it’s the disbelief. Nobody expected their own body to turn on something so familiar.
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The reasons allergies emerge later in life are varied (Source: AI Generated)
The medical reality: Why the body changes its mind
Doctors say this disbelief is understandable but increasingly outdated. “This I hear frequently from patients in the clinic,” says Dr Shivakumar Varakanahalli, Consultant-Medical Gastroenterology, at Aster Whitefield Hospital, Bengaluru. “’I have eaten this food all my life. What has made it problematic?’ Food sensitivities do not just affect children,” he says, noting a rise in adult diagnoses over the past decade, though he’s careful to distinguish allergy from intolerance. The latter, especially lactose intolerance, is far more common, driven by a natural decline in lactase production over time.
The reasons allergies emerge later in life, he explains, are varied: “Shifting things in the immune system, changes in the makeup of the gut microbiota, past infections, certain medications, and also broader environmental influences.” Since the gut steers immune regulation, disrupting that balance can cause the body to start reacting to once-harmless foods.
Dr Varakanahalli is also wary of the current cultural moment around food sensitivity. “What worries me the most is the sheer number of folks who decide they have something based on social media posts, or on those commercial ‘food sensitivity’ tests that have very little solid science behind them,” he says. By the time patients reach him, they’ve often already eliminated dairy, wheat and more—without knowing if any of it was ever the actual cause.
Dr Shilpa Singi, Lead Consultant in Internal Medicine at Aster Whitefield Hospital, Bengaluru, frames it as a question with no single answer. “Our immune system is a living organism that constantly changes throughout our lifetime, along with our reactions to food,” she says. Gut infections, chronic inflammation, microbiome shifts, certain viruses, acid-suppressing medications, hormonal changes during pregnancy or menopause, and simple ageing can all tip the balance. “We still have some questions,” she says, “but we do know that there are medical causes of adult-onset food allergy, and you should not dismiss the idea out of hand.”
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Dr Rakesh Aga, Director of Gastroenterology at PB Health, adds important nuance in terminology—a distinction almost every person interviewed for this piece stumbled through before getting a diagnosis.
A food allergy is immune-mediated, often IgE-driven, and can escalate to anaphylaxis within minutes. A food intolerance, by contrast, is a digestive issue with no immune involvement—uncomfortable, but not life-threatening. And “food sensitivity” has no fixed medical definition at all, which is precisely why commercial IgG-based sensitivity tests are, in his words, “not scientifically validated” and not endorsed by major allergy bodies.
Among adults, shellfish allergy stands out as one of the most common new-onset allergies, while lactose intolerance remains the most common intolerance worldwide, generally worsening with age. Wheat-related complaints deserve particular caution, Dr Aga notes, since coeliac disease, wheat allergy, and non-coeliac gluten sensitivity are three entirely different conditions requiring different tests and treatments—and coeliac testing must be done while still eating gluten, or results can be falsely reassuring.
What doctors want you to do
Every doctor converged on the same warning: don’t self-diagnose, and don’t eliminate multiple foods at once based on the internet.
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“The first thing I would advise patients to do is not to panic and not to eliminate several foodstuffs at one go,” says Dr Varakanahalli. Instead, track the pattern of which food causes problems, how quickly symptoms appear, and whether they’re purely digestive or involve skin, swelling, or breathing difficulty. That distinction alone often separates an intolerance from an allergy.
Dr Singi echoes the same caution against eliminating foods without proper testing, calling it a common error alongside the opposite mistake, continuing to eat a trigger food repeatedly, hoping symptoms will fade. “Instead, get yourself tested by a specialist,” she advises.
As for prevention, the doctors are honest about its limits. Lactose intolerance, driven by declining enzyme levels, is largely genetic and unavoidable. Food allergies have no proven prevention strategy either. What helps, they agree, is simply maintaining overall gut and immune health—a balanced, fibre-rich diet, avoiding unnecessary antibiotics, managing chronic conditions, and getting proper rest.
But can adult-onset food intolerances be avoided? Dr Singi says that whether prevention is possible “depends on whether you are referring to food intolerance or allergy since these conditions are entirely different”. Lactose intolerance, she explains, is “mainly genetic and something that one cannot evade” as it develops naturally as lactase production declines with age. There’s also no proven benefit to pre-emptively avoiding common foods, she adds; doing so unnecessarily “may cause nutritional deficiencies”.
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Her advice is to focus on a balanced diet, avoid unnecessary antibiotics, keep chronic conditions in check, and get enough rest and exercise to keep the immune system functioning well.
Dr Aga offers more actionable steps. “Not all food intolerances can be prevented because many are related to genetics, ageing or underlying medical conditions,” he says. That said, he points to steps that may help prevent secondary intolerances: maintaining good gastrointestinal health, promptly treating conditions like coeliac disease or inflammatory bowel disease, managing gastrointestinal infections early, and avoiding medications that unnecessarily disrupt the gut microbiome.
For people with Irritable Bowel Syndrome in particular, he recommends identifying personal dietary triggers with a gastroenterologist or registered dietitian with a targeted approach that, he notes, improves symptoms “without unnecessarily restricting the diet”.