Coffee: the unfiltered truth

For decades, we’ve read newspaper headlines about coffee increasing the risk of cardiovascular disease, high blood pressure and certain cancers. But times – and scientific opinions – change. In fact, they’ve done a 360 in the past few years.

It started in 2016 when the World Health Organisation removed coffee from its list of possible carcinogens, and designated the drink protective against cancer of the liver and uterus.

Then in 2019 a study part-funded by the British Heart Foundation (BHF) found coffee didn’t cause stiff arteries (which can lead to heart attacks and strokes), as previously thought. Further reviews suggested coffee may protect against Parkinson’s disease, diabetes, colorectal cancer and dementia.

The most convincing findings came earlier this year when a decade-long study by Queen Mary University London and Semmelweis University in Hungary cemented the drink’s health-giving properties.

Of the half a million people observed, those who drank up to three cups of coffee a day were 12 per cent less likely to die than non-drinkers, and around a fifth less likely to die of a stroke and heart disease.

So why the about-turn? “Coffee used to have a bad reputation for heart health, possibly because previous research was flawed,” says Victoria Taylor, senior dietitian at the BHF. “Older observational studies into large groups of people didn’t take out other lifestyle factors – for instance, coffee drinkers who also smoked.”

Then there’s the difference in how the hot drink was produced; in one of the original studies participants drank Swedish coffee, which is unfiltered and hence not heart-friendly because fats in the beans can raise cholesterol.

So what’s behind its superpowers? Before you put it all down to the caffeine it contains, consider this: many of the studies found that drinkers of decaffeinated experienced similar health benefits.

“There are hundreds of biologically active compounds in coffee, and we don’t know for sure which are behind the benefits,” says Dr Duane Mellor, at Aston Medical School.

“Small amounts of polyphenols [plant chemicals] from the coffee make it into your liver. They are powerful antioxidants and help your body deal with harmful free radicals by supporting the liver so it can better prevent disease. They’re also likely to improve your gut microbiome.”

Health credentials aside, this hot beverage isn’t for everyone. Caffeine is a central nervous system stimulant that can heighten feelings of anxiety and cause palpitations. Then there’s insomnia.

Dr Mellor advises, “The half-life of caffeine in the body is about five hours for a younger person, but older people should leave a longer gap between their last cup and bedtime because their body’s metabolism isn’t as efficient.”

Filter coffee made with paper filters, pods (eg Nespresso), and the frothy coffee-shop types made in professional espresso machines, and by stove-top Moka pots. Stick to two to three daily cups; research finds no extra benefits beyond three.

Lightly roasted (or blonde) beans have more nutritional value than dark roasted because roasting reduces the phenol (antioxidant) content. A study in the journal Antioxidants said that unroasted beans contain nearly double the antioxidants of roasted.

Robusta beans contain more antioxidants than Arabica beans when lightly roasted, but when dark roasted, the beans have the same antioxidant content.

“The best option is an Americano (filter coffee), black or with skimmed milk,” says Taylor. “If you have a latte, try oat milk. Oats help maintain normal cholesterol.”

This article first appeared in the June 2022 edition of Saga Magazine. Like what you’ve read? Subscribe to Saga Magazine today.