What’s the first thing you do when you arrive at work? Unpack your bag, set up your desk – and then make a beeline for the coffee machine? You’re not alone.
According to the National Coffee Association, the average American drinks just over three cups of coffee a day. In moderation, coffee is often seen as part of a healthy lifestyle, and for good reason – it’s been linked to a reduced risk of conditions like diabetes and even certain types of cancer.
But your morning brew might have a less wholesome side, too. Coffee contains natural compounds that can raise cholesterol – and depending on how it’s prepared, your daily pick-me-up could be giving you more of them than is ideal.
Now, a team of researchers in Sweden has taken a closer look at workplace coffee machines – and found that many produce coffee with relatively high levels of these cholesterol-elevating substances.
“We’ve known for decades that certain types of coffee can increase cholesterol levels,” Dr David Iggman, co-author of the new study published in the journal Nutrition, Metabolism and Cardiovascular Diseases, told BBC Science Focus.
In particular, unfiltered or boiled coffee is known to contain two cholesterol-raising compounds – cafestol and kahweol – which belong to a group of naturally occurring fats called diterpenes.
These have been associated with higher levels of LDL (or “bad”) cholesterol and an increased risk of cardiovascular disease. They’ve also been shown to slightly reduce HDL (“good”) cholesterol.
Filtered coffee, by contrast, tends to contain far lower levels of these substances and is considered a safer choice in this respect.
“But at work, we get a lot of coffee from machines,” Iggman said. “And no one has really tested these before. Are they like filtered coffee or unfiltered – or somewhere in between? We wanted to find out, because people drink a lot of this stuff, and they may not realise it could be an unrecognised part of their diet that affects cholesterol.”
To investigate, the team tested 14 coffee machines across a range of workplaces. For each, they took samples brewed on different days and measured the levels of cafestol and kahweol in the final cup.
For comparison, they also analysed other common types of coffee, including Scandinavian-style drip coffee, percolator, French press, espresso and boiled coffee.
The results? There was a wide variation between machines – partly due to the small sample size, Iggman said – but a pattern did emerge.
“From our data, we can say that liquid-model machines are definitely the better option,” he said. “Most of these produced coffee with very low levels of diterpenes – similar to what you’d get with paper-filtered coffee.”
Liquid-model machines don’t brew coffee in the traditional sense. Instead, they combine a liquid coffee concentrate with hot water to create your cup.
In contrast, brewing machines use ground or whole beans and typically pass hot water through a metal filter – resulting in higher levels of cholesterol-raising compounds.
So, what’s the bottom line?
“You shouldn’t be worried about drinking coffee,” Iggman explained. “Overall, it’s been linked to a range of health benefits.”
That said, if you’re drinking multiple cups of machine-made coffee every day at work – and especially if you’re already monitoring your cholesterol – it might be worth paying attention to how it’s brewed.
“We still don’t know exactly how much these machines affect blood lipids,” he adds. “It probably depends on how much coffee you’re drinking. But if you want to be on the safe side, coffee passed through a paper filter or instant coffee are the best options – both are neutral when it comes to your cholesterol.”
About our expert
David Iggman is an associated researcher at the Center for Clinical Research Dalarna, Uppsala University, Sweden. His research has been published in prestigious journals such as The American Journal of Clinical Nutrition, Diabetes and the Journal of Internal Medicine, among others.
Read more: