Coffee bad, red wine good? Top food myths busted. Illustration: Lalalimola/The Guardian/Getty Images
We’re being bombarded with conflicting advice on what we should and shouldn’t put into our bodies. Finally, here are the definitive answers, according to the experts
Modern nutritional science is only a hundred years old, so it’s no surprise that we’re constantly bamboozled by new and competing information about what to put into our bodies – or that we sometimes cling to reassuringly straightforward food myths which may no longer be true. In a world where official dietary advice seems to change all the time, and online opinions are loud and often baseless, we ask eight food and drink experts to cut through the noise and tell it like it is.
What’s the truth about coffee?
“I’m surprised that people still think coffee is bad for them,” says Dr Astrid Nehlig, research director of the French medical research institute, Inserm, and one of the world’s leading researchers into coffee, health and brain function. When she first started researching coffee 30 years ago, she often encountered producers who were nervous that their products might be found to be harmful. “But a lot of progress has been made in the last 10-15 years.”
So what do we know, now? “Coffee contains more than 1,000 compounds, so what we are looking at is not just about caffeine,” says Nehlig. “It increases alertness but at the same time relaxes us. It focuses and increases attention, but prevents sleep, especially if you drink too much, or too late.” We are not all equal on this front: caffeine targets our brain’s adenosine receptors but half of us are immune to this effect – which explains all those people who drink espresso after dinner and conk out at 11pm. “It’s also about the accumulation of caffeine during the day, which is related to how we metabolise caffeine – in one group of the population, caffeine builds up in the body, but the other group eliminates it very quickly.”
Nehlig adds: “Coffee has often been accused of being bad for heart health. But we now have global research showing that coffeeit is protective against cardiovascular disease, stroke and coronary heart disease, and decreases mortality linked to cardiovascular issues.” Nehlig says there is also clear evidence that coffee protects against type 2 diabetes, regardless of body fat; it’s definitely protective against Parkinson’s disease and almost certainly against cognitive decline in general. Coffee does not increase our risk of cancer. “It’s neutral, or even protective in some cancers, like the liver, colon, endometrium and some non-hormonally dependent breast cancers.” Quite why this is, isn’t yet known; Nehlig’s hunch is that it’s to do with coffee’s range of antioxidants.
This isn’t a licence to knock back as many flat whitesas possible, though. “Research shows adults shouldn’t go over 400mg a day, which is 4-5 small cups, and no more than 200mg in one sitting.” (Coffees from high-street chains can contain as much as 300mg in a large serving.)
“For some people caffeine will either trigger anxiety or worsen symptoms of anxiety,” says Murray Carpenter, author of Caffeinated: How Our Daily Habit Hooks, Helps and Hurts Us. “Some who really suffer from anxiety have never experimented with eliminating or minimising caffeine.” (My own anxiety got so bad that I had to give up caffeine during the worst of the pandemic in 2020. I still miss it.) Caffeine also worsens insomnia. “In both scenarios, I think it’s important that people experiment with changing their caffeine habits and see what improves,” says Carpenter. It won’t be a silver bullet for everyone. “But if you don’t experiment, you won’t know.” The Grauniad.
