No single “immune-boosting” food can protect you from Covid-19 – but diet can help

 

Eating lots of diverse plants is one way to support the immune system, but there is no magic bullet to protect us against infection. 

 

Sign Up

Get the New Statesman's Morning Call email.

In a year that has already offered a lot to be angry about, the endless emails popping into my inbox touting “immune-boosting” foods to help beat coronavirus have nevertheless proved a reliable way to raise my blood pressure. Pizza toppings “packed with vitamin C and lycopene”, sugary “immune-support” cereal bars, turmeric “lattes” and even the “natural immunity”-activating powers of chocolate have all been touted as magic bullets to protect us against infection. It’s almost enough to drive me to gin, one of the few things that I haven’t seen advertised as a handy virus repellent.

When I met Tim Spector, professor of epidemiology at King’s College London, nominally it was to talk about his new book, Spoon Fed: Why Almost Everything We’ve Been Told About Food is Wrong. Inevitably, we talked far more about coronavirus, given he has since developed the Covid-19 Symptom Study app – and I asked him if my scepticism was warranted. He confirmed that the only way to protect yourself against the virus is to avoid coming into contact with it; no one food is going to stop you getting it, or cure you if you do. (Indeed, the study website explains that boosting one’s immune system is not straightforward; an overactive immune response can be as dangerous as an underactive one, leading to inflammation and autoimmune conditions. In serious cases, it can kill you.)

Spector is also sceptical about vitamin and mineral supplements, which he believes data will soon show to have had no benefit in this case. “The sad thing is people can officially make claims on any foods,” he says. “Sprinkle a bit of zinc on it and you can call it an immune-boosting food.”

He hopes the symptom tracking app, which is used by more than four million people, will show a link between “good food, good gut health and good immunity” – thinking about combinations of foods rather than individual ones. Eating “lots of diverse plants” is probably a good way to support the immune system, Spector reckons, plus fermented foods such as live yoghurt, traditional cheeses, kombucha and kimchi, all of which will help increase the variety of your gut microbiome by delivering a fresh dose of live microbes straight to the source. (Though the relationship between the gut and the immune system is still not fully understood, it seems to play a key role in the body’s response to infection.)

The other, potentially less pleasurable, way we can help ourselves is to keep an eye on our waistlines: people who are “very overweight tend to suffer the worst effects of coronavirus”; those with a BMI over 30 are at least 20 per cent more likely to be hospitalised. The study found almost a third of participants put on weight in lockdown, and Spector says he was “very excited” when Boris Johnson announced an obesity strategy, but the measures themselves (restrictions on the promotion of foods high in fat, sugar and salt, and calorie counts on restaurant menus) proved a disappointment: “A Band-Aid over a severed head.”

And though it has little time for calorie counting, or one-size-fits-all diets, Spector’s book does caution against the modern world’s obsession with grazing, the habit that has probably piled the pounds on to many of us, unused to spending our days in such proximity to the fridge. We should “fight the need to snack and hydrate constantly”, he concludes. Even on those special immune-activating chocolate bars. 

Felicity Cloake is the New Statesman’s food columnist. Her latest book is The A-Z of Eating: a Flavour Map for Adventurous Cooks.

This article appears in the 02 October 2020 issue of the New Statesman, Twilight of the Union

Free trial CSS