Heart disease is the No. 1 cause of death for Americans, with stroke trailing cancer as the third leading cause, according to the Centers for Disease Control. Your doctor uses your lipid profile to help predict your risk of developing these diseases, although it is not the only predictor. Coffee consumption has been a hot topic in research, both in terms of its acute effect on a fasting lipid profile, as well as its overall potential to modify cardiac disease risk. Studies show that drinking black coffee in the morning before you have a fasting lipid profile may affect your results slightly, but not enough to matter to your doctor. The test will still accurately measure the type and amount of lipids, or fats, in your blood. Even though it won't be apparent from your lipid profile, drinking a moderate amount of coffee on a daily basis may have a positive effect on your cardiovascular health.
Your Lipid Profile
Your lipid profile includes several numbers: total cholesterol, LDL, HDL and triglycerides. Before it travels into your bloodstream, your liver packages much of the fats and oils from your diet with cholesterol into droplets called lipoproteins. After most of the fat from the lipoprotein molecule gets dropped off to the various cells of your body to be used for energy and stored, most of what is left is cholesterol and is called a low-density lipoprotein, or LDL. LDL cholesterol is harmful because it can develop into a hard plaque inside the arteries that makes it more difficult for your blood to reach your heart, brain and other organs. When you eat a diet high in unhealthy saturated and trans fats, more LDL cholesterol builds up in the blood. The higher your LDL number, the higher your heart attack and stroke risk.
High-density lipoprotein, or HDL, acts like a sponge, cleaning out cholesterol from the arteries. Various factors influence how much HDL you have, most of them non-dietary. To remember which type of lipoprotein is which, think of the L in LDL as the “loser” and the H in HDL as the “hero.”
Triglycerides are the storage form of fat in the body and should ideally be less than 150 mg/dL. Total cholesterol should be less than 200.
Coffee and Lipids
Boiled, unfiltered coffee, such as the type prepared in Scandinavian cultures, contains fat-based compounds known as diterpenes -- or cafestol and kahweol -- which have been shown in research to increase total cholesterol, LDL and triglyceride concentrations. Arabica beans have more diterpenes than Robusta, and finely ground coffee contains more than coarser grinds. The coffee commonly consumed in the United States and most of western Europe is usually filtered, a process that removes the majority of these compounds, and therefore appears to have little influence on blood lipids. Decaffination and roasting time also don’t seem to affect the level of diterpenes in coffee.
When she measured the lipid profiles of 40 adults who had been fasting 30 to 60 minutes after drinking 6 ounces of either filtered black coffee or filtered coffee with nondairy creamer and sugar, Rebecca Cheung and her colleagues at the University of the Pacific in California found that the participants' LDL levels were not significantly different. Results were published in the July-August 2005 issue of "The Annals of Pharmacotherapy." Researchers in Italy found a similar outcome, as reported in the September 2007 issue of the “American Journal of Clinical Nutrition.” Cheung also found that total cholesterol and HDL did increase by a few points in the subjects who had consumed the black coffee, but it was not enough to be considered clinically significant. Triglycerides were not affected in the black coffee drinkers, but were noted to fall slightly in the flavored coffee group.
Potential Benefits
Filtered black coffee doesn’t seem to immediately affect lipid levels, but it may help to decrease overall cardiovascular disease risk. Phenolic compounds in coffee have been found to have antioxidant properties. As it turns out, it’s not the LDL alone that damages arteries, but the oxidation process that happens when certain types of white blood cells try to clean the LDL out of the blood. In an article published in the "American Journal of Clinical Nutrition" in 2007, Fausta Natella and colleagues showed that subjects who drank 200 milliliters of filtered coffee had resistance of their LDL to oxidation. Phenolic compounds are at least partially lost in the filtering process, but based on the results of this study, some benefit is still preserved. Natella points out that previous studies that have looked at the affect of drinking coffee on a consistent basis over a longer period of time have shown a similar benefit.
Recommendations
What it all boils down to is that if you are told not to eat before having bloodwork to test your lipids, you can drink up to 6 ounces of black coffee about an hour beforehand, and it won't significantly affect the outcome. However, if you are trying to improve your cholesterol numbers, it makes sense to be consistent each time you are tested. For example, don't drink coffee before one test but not before the next because your numbers may be slightly off. In addition, moderate consumption -- a few cups -- of filtered black coffee consumed daily won’t impair your lipid levels or cardiac risk, and it may actually help, due to coffee's antioxidant qualities. Keep in mind, though, once you start adding large amounts of calories in the form of sugar and saturated and trans fat from dairy and nondairy creamers, you will likely cancel out any potential benefit you may receive from your daily brew.
References
- “Journal of Nutrition”; Cholesterol-Raising Diterpenes in Types of Coffee Commonly Consumed in Singapore, Indonesia, and India and Associations With Blood Lipids: A Survey and Cross Sectional Study; May 2011
- "The Annals of Pharmacotherapy"; Acute Coffee Ingestion Does Not Affect LDL Cholesterol Level; Cheung RJ, et al; July-August 2005
- “American Journal of Clinical Nutrition”; Coffee Drinking Induces Incorporation of Phenolic Compounds Into LDL and Increases the Resistance of LDL to Ex Vivo Oxidation in Humans; Natella F, et al.; September 2007
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