Cholesterol is a waxy substance produced by the liver. It is found in all cells of the body, and is needed to make hormones, vitamin D, and substances that help digest foods. Cholesterol travels through the blood stream in small packages called lipoproteins. These packages are made of lipid (fat) on the inside, and proteins on the outside. There are two kinds of lipoproteins that carry cholesterol; low-density lipoproteins (LDL) and high-density lipoproteins (HDL). Having healthy levels of both is important, but LDL cholesterol is sometimes called bad cholesterol, as too high a level of LDL leads to a build up of cholesterol in the arteries which can cause medical issues such as cardiovascular disease. HDL cholesterol is sometimes called good cholesterol, as it carries cholesterol from other parts of the body back to the liver, where it is removed from the body.1
Impact of coffee and caffeine on cholesterol levels
Over the past 10 years, multiple studies have found a link between coffee and elevated blood cholesterol levels. One of the studies claims this is due to the coffee oils (diterpenes), such as cafestol and kahweol, that are found in both caffeinated and decaffeinated coffee. Cafestol has been indicated to affect the body’s ability to metabolize and regulate cholesterol. According to meta-analysis of controlled studies, coffee oils may also decrease bile acids and neutral sterols, which would potentially lead to an increased blood cholesterol level. Researchers of one study even concluded that cafestol could be, “the most potent cholesterol-elevating compound identified in the human diet”.
It was also found that the method of brewing has an impact on the potency of coffee oils. They are most potent when the coffee has been in contact with the water during brewing; a French press brewing method (water is passed continually through the coffee) has far higher concentrations of cafestol than brewing coffee in an American-style coffee pot with a filter, as the water is only passed through the coffee once. Most of the cafestol is therefore left behind in the filter. Another study found that coffee simmered in the Turkish style, or boiled in the Scandinavian style had the highest amount and concentrations of coffee oils, whereas the amount in drip-brewed and instant coffee had “negligible” amounts. Espresso was found to have medium amounts.4
Research has shown that drinking 5 cups of coffee daily from a French press brewing method can increase blood cholesterol levels by 6-8% by cafestol effectively hijacking a receptor in the intestinal pathway critical to regulating blood cholesterol levels.5