Does Coffee Raise Cholesterol? It Depends on the Filter

Unfiltered coffee raises LDL cholesterol. Paper-filtered coffee barely does. The difference comes down to one compound, cafestol, which a paper filter holds back and a metal mesh lets through — so if your cholesterol is a concern, the fix is not giving up coffee but changing how you brew it.

This is one of the few areas of coffee and health where the cause is well understood, the trials are clear, and the advice is simple.

The culprit: cafestol

Coffee beans contain oily compounds called diterpenes. The two that matter here are cafestol and, to a lesser extent, kahweol. In a 1997 review in the Annual Review of Nutrition, the Dutch researchers Rob Urgert and Martijn Katan set out what decades of research had established about them:

• They make up about 1% of the weight of coffee beans.
• Hot water extracts them into the brew.
• Paper filters retain them.

That last point explains everything that follows. A paper filter traps the fine oily droplets that carry cafestol. A metal mesh, a cloth or no filter at all lets them through into the cup.

Cafestol appears to act on the liver, altering how it regulates cholesterol and bile acids. The effect is strong for the amounts involved: intakes measured in milligrams a day show up in blood tests within weeks.

What the trials show

The firmest evidence comes from randomised trials, where people are assigned to drink particular coffees and their cholesterol is measured.

In 2001, Sun Ha Jee and colleagues pooled 14 randomised controlled trials in a meta-analysis in the American Journal of Epidemiology. They found:

• A dose-response relationship: the more coffee, the larger the rise in total and LDL cholesterol.
• Larger increases in trials of boiled coffee, and in people who already had high cholesterol.
• Very little increase in trials of filtered coffee.

Their conclusion was unambiguous: consumption of unfiltered, but not filtered, coffee increases serum total and LDL cholesterol.

How much cafestol is in your cup

In 1995 Urgert and colleagues measured the diterpenes in a range of coffee brews, in the Journal of Agricultural and Food Chemistry. The pattern they found is the one that matters for choosing a method:

Espresso's position is partly about volume. Espresso is brewed through a metal basket and carries plenty of coffee oil — the crema is full of it — but a single shot is small, so the amount per cup stays modest.

Brewing methods, sorted

Let cafestol through — unfiltered or metal-filtered:

• Boiled coffee (Scandinavian kokekaffe, cowboy coffee)
• Turkish coffee and other unfiltered pot methods
• Moka pot, which brews through a metal filter plate
• French press and other metal-mesh brewers
• Metal-filtered pour-over cones and reusable metal filters
• Espresso, to a moderate degree

Hold most of it back — paper-filtered:

• Pour-over with paper: V60, Chemex, Kalita
• Drip coffee machines with paper filters
• AeroPress with its paper filter
• Instant coffee

Cold brew depends entirely on how you filter it. Strained through cloth or a mesh alone, it keeps its oils; finished through paper, it does not.

Does it matter for health?

Cholesterol is a risk marker rather than an outcome, so the natural question is whether brewing method shows up in harder endpoints.

The largest study on that question is Norwegian. Aage Tverdal and colleagues followed 508,747 adults for around 20 years and published the results in the European Journal of Preventive Cardiology in 2020. Unfiltered coffee was associated with higher mortality than filtered coffee — and filtered coffee was associated with lower mortality than drinking no coffee at all.

That is an observational study, so it shows association rather than proof. But it lines up with the trial evidence and the known mechanism, which is about as much agreement as nutrition research gets.

What to do

• If your cholesterol is normal, and you enjoy French press or espresso, there is no need to give them up. Consider making paper-filtered coffee your everyday default and the others your occasional pleasure.
• If your LDL is high, or you have familial hypercholesterolaemia, switch your daily coffee to a paper-filtered method. It is one of the easiest dietary changes available, and it does not require drinking less coffee.
• If you love the French press, pour the finished brew through a paper filter. You lose some body; you keep most of the flavour and remove most of the cafestol.
• Do not worry about instant or filter coffee on cholesterol grounds; their cafestol content is negligible.

For the broader picture on coffee and health — including why most of the evidence is reassuring for moderate drinkers — the coffee and health guide covers the major reviews.