In the past, it was thought that any effect of coffee on the cardiovascular system was likely to be due to caffeine. Many studies therefore only tested for the effect of caffeine. However, consideration should be given to other factors, such as polyphenols, as well as the potential effect on circulating cholesterol levels.
Coffee and cholesterol
The diterpenes cafestol and, to a lesser extent, kahweol, both naturally present in coffee oil, can raise the serum levels of both total and LDL-cholesterol6. Whether these diterpenes permeate into brewed coffee, and to what extent, depends on the brewing method. For Scandinavian boiled coffee, cafètiere (plunger pot), Greek and Turkish coffee, these components can pass into the brew, whereas they are largely retained in the paper filter in filtered coffee. Soluble coffee contains hardly any of these diterpenes. Espresso coffee contains approximately half the amount of diterpenes of unfiltered coffee, although precise amounts do depend on portion size. The effects on cholesterol levels are transient6.
A 2022 study suggested that espresso coffee consumption was associated with increased serum total cholesterol (S-TC), with a significantly stronger association for men compared with women. Boiled/plunger coffee was associated with increased S-TC in both sexes and with similar magnitude as shown in previous research. Filtered coffee was associated with a small increase in S-TC in women but not men8.
The antioxidant potential of different foods and beverages also provide further insight into potential mechanisms. Research published in 2016 concluded that coffee consumption increases the antioxidant capacity of plasma, therefore the overall effect of this on the body could be interesting30.
A 2017 review concluded that many of the protective effects of coffee have been associated with chlorogenic acids, however there are very few intervention studies on pure chlorogenic acids in humans. One of the difficulties in making conclusions on the polyphenol component of coffee is separating out the effects of caffeine, which itself has notable biological activity31.