I was a carnivore once. Not long ago I’d eat meat for lunch and dinner (and four eggs — often fried — for breakfast). Vegetables were incidental: maybe peppers with chorizo; carrots and celery in a casserole. A meal without meat was no meal at all.
I was in my early thirties and I didn’t consider myself unhealthy. I exercised almost daily. I was strong. I could run quickly and cycle for hours.
And yet I’d always been a bit of a phlegmy boy, afflicted by what I thought was a series of colds. Only when I was 15 and I smashed my tennis racket on the first morning of our summer holiday — angry about losing, blinded by sneezing — did I recognise this for what it was: simple, infuriating hay fever. It explained why, when the heavy days of spring and summer came down, I’d feel bothered in every pore, scrubbing my eyes and sneezing incessantly.
Government figures suggest that hay fever now affects 10 to 15 per cent of children and 26 per cent of adults in the UK; cases have trebled in the past 20 years as pollen counts have risen with temperatures. The charity Allergy UK goes further: it says that up to 49 per cent of the UK population suffers from symptoms.
Aged 15, two decades ago, I accepted my fate. There began my expensive relationship with antihistamines. Cetirizine. Loratadine. Pills, sprays, drops. Up the nose or in the eyes or down the throat. Every year in greater and greater volume. And did the sneezing stop? Did my swollen lids cease to itch? Sometimes, for a little while. But generally the trend was for more: more irritation, more drugs. It would start in March, when the trees began producing pollen, then intensify between May and July when my true nemesis, grass pollen, got in on the act and up my nose.
If I drank alcohol the deterioration was clear. But beyond that I saw no pattern and in winter I would largely forget, until spring broke again and my brother-in-law — a Highlander who seems largely unbothered even by insect bites — would start to mock my urban constitution.
Two years ago, I noticed a change. In January 2024, aged 32, I made substantial changes to my diet. Meat and alcohol were out, replaced by beans, Greek yoghurt, nuts and copious blueberries. My reasons were superficial and incoherent: I wanted to diversify my menu (I could cook, but only meat). When I ran I often felt the weight of all that meat in my stomach. I’d read Christopher McDougall’s inspiring but hyperbolic book Born to Run — about ultra-athletes and the distance runners of the Mexican Tarahumara tribe — and wanted to test his claims that your digestive tract can easily function on a plant-based diet. And, critically, I was dating a vegetarian, whom I wanted to impress.
She was not impressed. Still, by the end of that month I was feeling elastic and light, so I decided to stick with the new regimen. I ate meat sparingly; I devoured chickpeas by the cartonload; and fed up with the fog and anxiety that followed drinking, I ditched the booze.
In the sodden early weeks of spring 2024 I waited for the sneezing and the itching to start. Instead, I returned from long bike rides that would once have left me puffy and red-eyed, feeling composed and still not reaching for the pills. I assumed this was down to the changing climate: the season was out of tune — perhaps the pollen count was just low? But when the rain finally stopped, my good health endured. Last year my symptoms eased further still; they were more or less non-existent.
Ecstatic, baffled, I started to theorise. Was I… cured?
“Well, you probably didn’t cure your hay fever,” says Theresa MacPhail, a medical anthropologist and the author of Allergic. “But you’ve accidentally changed the make-up of your gut microbiome because you’ve been feeding it different bacteria.” For perhaps the first time in my life I’d been nourishing myself properly — and one of the rewards seemed to be the end of my hay fever.
The function of the body’s immune system, I discovered, is now thought to be largely linked to the gut.
“When our microbiome is diverse and balanced it helps our immune tolerance,” says Dr Sabine Donnai, a GP who founded the Viavi longevity clinic. “Antibiotics, low-fibre diets and even keeping our environment too sterile can disrupt the microbiome. Then it is more likely to overreact to simple, harmless triggers such as pollen.”
I was delighted to be joining the ranks of people who could describe pollen as “harmless”.
Professor Tim Spector, the epidemiologist and co-founder of the nutrition company Zoe, says there is “pretty solid” proof of a relationship between the gut microbiome and hay fever (and growing evidence of its influence on our airways in general).
A lack of microbial diversity is common in allergy sufferers, he says — which means fewer of the beneficial bacteria that digest fibre to produce the short-chain fatty acids (SCFAs) that play a big part in many aspects of our health.
The immune system is affected because it “trains” on the bacteria in the gut, MacPhail says. “It learns to recognise friend and foe.” SCFAs are critical to this schooling. They also contribute to the manufacture of T-cells, which dampen allergic responses and prevent the overproduction of cytokines, which can cause chronic inflammation, an issue linked to allergies, Alzheimer’s and cardiovascular disease.
Without this “training” the immune system can become hyperactive, needlessly responding to pollen by producing histamine. Hence all those antihistamines I’d been taking. “Histamine can cause swelling in the body because it alters the blood vessels and the blood flow,” MacPhail says. This is what causes itching and the build-up of mucus.
But — and here comes the caveat — MacPhail warns that changing your diet as I did, to include more fibre and a broader variety of plants, is not guaranteed to be universally effective for hay-fever sufferers. Each gut microbiome and immune system is unique and, MacPhail says, improving your diet “is not a smoking gun”.
Illustration by Emanuel Santos for The Sunday Times MagazineImmune systems also change with age, environment and geography. Our immune response softens as we age, so older people might suffer less from allergies (though more from infectious illness).
“Hormone changes can affect the immune cells,” MacPhail explains — pregnancy can induce allergies, for instance. “As can changes in diet or sleep.”
My decision to cut out alcohol also played a part. Besides diminishing gut microbiome diversity, booze also aggravates allergies by ramping up the release of histamine and suppressing the production of diamine oxidase, the enzyme that breaks it down. “You don’t need to have been a heavy drinker to see the positive effect of stopping,” Spector says.
So my love for the warmth of spring and summer is no longer compromised. I’ve improved my health generally and gained valuable knowledge (for instance, I learnt that running soon after a bowlful of beans is not without danger).
But I can’t totally relax. Pollution, stress and urban life all aggravate hay fever; living in London I have little prospect of escaping those any time soon. My intrinsic susceptibility to hay fever won’t have vanished, MacPhail says. “Probably some cells are still firing in you.” So I may yet get my comeuppance for feeling smug. But we’ll see — spring is upon us. Will I make it through sneeze-free?
