Dr. Rhonda Patrick

First, diterpenes, specifically caftol and kiwiol.

These are fat-soluble molecules that naturally are found in coffee beans.

The problem with these diterpenes is that they significantly raise LDL cholesterol.

In fact, studies have found that people who regularly drink unfiltered coffee, like from French press, espresso, or boiled coffee, it can raise their LDL levels by roughly 10 to 30 milligrams per deciliter within just a few weeks.

And that does increase cardiovascular disease risk.

There's also links between higher diterpene exposure from unfiltered coffee with slightly elevated risk of certain cancers.

Second and more beneficially, coffee beans are rich in polyphenols, primarily the chlorogenic acids.

Polyphenols are powerful antioxidants that reduce inflammation, oxidative stress, protect us from chronic diseases.

Unlike diterpenes, polyphenols are water-soluble, so they dissolve in water and easily pass through paper filters.

Here's why this chemical difference matters.

Brewing methods dictate how much these compounds end up in our coffee.

Unfiltered methods like espresso, French press, boiled coffee, or stovetop percolators retain the oily diterpenes.

For perspective, espresso contains around 1,100 milligrams of kafstal per liter.

Turkish boiled coffee contains around 900 milligrams per liter, while French press and mocha pots contain 70 to 90 milligrams per liter.

Practically, that means one espresso shot has about 30 milligrams of cafestol and a typical cup of coffee from other unfiltered methods have between 10 and 200 milligrams.

In contrast, filtered coffees like traditional paper drip, instant cold brew, trap these diterpenes in the filter, essentially eliminating their negative effects while still preserving beneficial polyphenols.

Recent studies have shown that even workplace coffee machines, which usually lack proper filtration, deliver significantly higher diterpene concentrations, between 140 to 170 milligrams per liter, compared to filtered coffee prepared at home, which often shows undetectable levels.

As a side note, I do want to mention that many traditional paper drip coffee machines do run hot water through plastic.

So if you are going to do a filtered coffee, pour over is probably your best bet, doing something into a glass container and not having the hot water touch plastic.

Just something to keep in mind.