If you have high cholesterol, could your morning cup of Joe be at least partly to blame? Maybe, depending on how your coffee is brewed and how much you drink.

Most research has found that coffee drinking in general does not increase blood cholesterol or cardiovascular risk. But since the mid-1980s, studies have consistently linked unfiltered coffee to increases in cholesterol. Much of the evidence comes from Scandinavia, where coffee typically is made by boiling the grounds in hot water and is not filtered.

What’s in your cup of coffee?

Diterpene compounds in coffee beans—notably cafestol—are responsible for the cholesterol-raising effect. The longer the coffee grounds come in contact with the brewing water, and the hotter the water, the greater the amount of diterpenes released. Scandinavian-style boiled coffee has the most diterpenes, studies have shown—followed by Turkish/Greek coffee, French-press (cafetière or plunger-pot) coffee and then espresso. American-style “drip” coffee has virtually none because the paper filters trap the compounds. Percolated and instant coffees also have negligible amounts. Decaffeinating coffee does not reduce diterpenes.

Still, it takes a fair amount of unfiltered coffee to have a significant effect on cholesterol. Daily consumption of 10 milligrams of cafestol—the amount in about four 5-ounce cups of French-press coffee—has been shown to raise cholesterol by 8 to 10 percent in four weeks, mostly due to increased LDL (“bad”) cholesterol. Some people are affected more than others, and the effects may be greater in those who have higher cholesterol to begin with.

The sunny side of coffee

All coffee, no matter how it’s brewed, contains a complex mix of phytochemicals, many of which are potentially beneficial. In fact, coffee is the No. 1 source of antioxidants in the U.S. diet, because we drink so much of it. Coffee has been shown to guard against oxidation of LDL cholesterol, which makes LDL less harmful. And it’s been linked to reduced risk of diabetes, Parkinson’s disease and some other disorders. Cafestol may even have anti-cancer properties, at least in lab studies.

Bottoms up

An occasional cup of unfiltered coffee won’t raise your cholesterol significantly, if at all. But you may be consuming more unfiltered coffee than you realize because many coffee drinks—cappuccinos or lattes, for instance—are made with espresso, sometimes more than one shot. If your cholesterol is high, you might want to limit espresso to one or two a day and not go overboard with French-press coffee.