Unfiltered coffee contains a substance called cafestol that increases LDL.
Coffee is one of the most widely consumed beverages in the world. While it may seem like science is constantly changing its position on whether coffee is good or bad for you, most research shows that, in moderation, coffee is perfectly safe -- and it may even be beneficial. Low-density lipoprotein, or LDL, is a type of cholesterol that can increase your risk for atherosclerosis and heart disease. Coffee does contain a substance that can sharply raise LDL levels. However, if you use a paper filter when brewing coffee, the effect of this substance can be minimized.
Coffee and Health
Dr. Rob van Dam writes on the Harvard School of Public Health website that drinking up to six cups of coffee per day is not associated with an increased risk for any disease, including cancer or cardiovascular disease. Dr. van Dam does notes, however, that most of the data on the safety of coffee is based on black coffee without cream or sugar. Coffee may help protect against certain diseases, including Parkinson's disease, diabetes, liver cancer and cirrhosis of the liver, but more research is needed in this area.
Cafestol and LDL
A substance in coffee called cafestol can significantly increase LDL cholesterol levels. In an article published in "Molecular Endocrinology" in 2007, researchers called cafestol "the most potent cholesterol-elevating compound known in the human diet." Luckily, most of the cafestol can easily be removed by filtering your coffee, as most people do. Certain unfiltered brews, which are much higher in cafestol, include Scandinavian boiled coffee, Turkish coffee and French-press coffee. Espresso contains less cafestol than French press, but more than filtered coffee.
Research Linking Coffee and LDL
Some research points to a link between increased LDL cholesterol and coffee consumption, with unfiltered coffee as the main culprit. A meta-analysis of 12 studies published in 2012 in the "European Journal of Clinical Nutrition" concluded that coffee, especially unfiltered coffee, can raise blood lipid levels. The meta-analysis showed that, on average, coffee consumption for a 45-day period correlated with increases in LDL cholesterol, total cholesterol and triglycerides.
Research Favoring Coffee
A study published in 2005 in "The Annals of Pharmacotherapy" tested the cholesterol levels of 40 participants one hour after consuming a single cup of coffee. The study revealed no clinically significant differences in total cholesterol, HDL or triglycerides, although there were statistically significant differences that weren't due to chance. However, these differences were not necessarily large enough to be of importance. But the differences for LDL were neither statistically nor clinically significant, suggesting that coffee does not increase LDL.