Triglycerides are fats found in the blood and used by the body to store excess calories. High triglyceride levels are linked to a variety of significant health problems, including an increased risk of heart attack and stroke; issues of the thyroid, liver or kidneys and conditions such as diabetes and metabolic syndrome. Dietary factors, including coffee consumption, often play a key role in determining triglyceride levels.
What we eat and drink has a significant impact on our triglyceride levels, according to the Cleveland Clinic. For example, reducing calories from fat, sugar, refined grains and alcohol can often decrease triglycerides without the use of medication. The clinic also recommends eating smaller portions, avoiding late-night snacks and getting regular exercise. The Cleveland Clinic does not advise adults to reduce or eliminate coffee consumption as part of a low-triglyceride diet.
Black coffee is considered generally neutral in terms of its impact on blood cholesterol and triglycerides. The U.S. Department of Health and Human Services' HealthFinder website lists black coffee and water as the only two substances permissible to consume before a "fasting" lipoprotein test, which measures both blood cholesterol and triglyceride levels. In fact, a 2005 study published in the Annals of Pharmacotherapy found that consuming a 6-ounce cup of coffee an hour before the test produced no clinically significant changes in blood cholesterol or triglycerides.
Although black coffee has a minimal effect on triglycerides, ingredients commonly added to coffee can have a strong impact. For example, cream, whole milk and half-and-half are all high in fat, which can dramatically increase triglyceride levels. Table sugar and sweet or flavored syrups can also be problematic, and the Cleveland Clinic recommends switching to non-sugar sweeteners. Those who enjoy an occasional Irish coffee or touch of liqueur in their java should also refrain, as alcohol is a very potent effect on triglyceride levels.
Drip vs. Press
In a 2004 edition of his medical newsletter, Dr. John McDougall describes the relationship between coffee and triglycerides. He points out that two chemicals found in coffee, cafestol and kahweol, can significantly raise blood cholesterol and triglycerides. The impact of these chemical is largely nullified, however, by the use of a paper coffee filter. This means that standard drip coffee, as prepared in many homes, restaurants and coffee shops—and permitted by many cholesterol testing facilities—is generally safe. Unfiltered, boiled coffee, such as the coffee produced by a French press, contains the harmful chemicals.
Dr. McDougall advises against consuming even drip coffee in large amounts, because caffeine can contribute to other health issues, including heart disease risk factors such as high blood pressure. However, the Cleveland Clinic and the HealthFinder website do not list caffeine consumption as an important consideration for patients with concerns about cholesterol or triglycerides. While drip coffee consumed black or with sugar substitutes should be generally "safe," you should consult a trusted physician or dietitian for specific guidelines based on your individual health, lifestyle and goals.