In developed countries where many people have an abundance of food and the luxury of choice, there also tends to be some level of anxiety about eating ‘correctly’, with people being bombarded with conflicting advice about what is good and what is bad for you. For those who do like to be better informed about this, this article explores some of the myths and summarizes the research on various foods that have been either praised or demonized: coffee, alternative milks, red wine, red meat, and carbohydrates. The article goes into some detail on the research on each but I will excerpt just some of the stuff on coffee, one of the demonized items.
“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.
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.”
Especially as one gets older, statistical analyses about marginal effects on longevity tend to be less salient since one’s life expectancy is not that great. I myself tend to not worry about what I eat as long as I practice moderation and follow food writer Michael Pollan’s general advice to “Eat food. Not too much. Mostly plants.” Within that general framework, I eat food that I enjoy eating and not worry about the health effects.