Coffee and Cholesterol

Last week we talked about coffee and its effects on the cluster of symptoms that make up Metabolic Syndrome, which include poor cholesterol scores, including high triglycerides and low HDL (good cholesterol); a high level of fat around the internal organs; high blood pressure and blood sugars; and waist measurements over 35 inches for women and 40 inches for men. While that study did not see a link between coffee and blood pressure or cholesterol scores, that was what is known as a cross-sectional study, in which the researchers look at a snapshot in time.

Today's research is an interventional study: one in which the researchers compare the effects of some kind of change (the "intervention") with the effects of no change (the "control group"). In an effort to measure the effects of different roasts of coffee on cholesterol levels, researchers in Brazil recruited 20 healthy men and women, regular coffee drinkers between the ages of 37 and 61, to participate in a coffee-drinking study (Nutrition 2013;29(7-8):977-981).

After 1 week of abstaining from coffee (boy, these volunteers must have been dedicated!), half of the participants drank 4 cups of medium-light roast per day for four weeks while the other half of the participants drank 4 cups of medium roast coffee daily for four weeks. Then the two groups switched their type of coffee and continued the study for an additional four weeks. The coffee in all cases was prepared with standardized machines using paper filters (and coffee) the researchers provided.

At the start of the study and at the close of each 4-week period, the volunteers provided blood samples so that their cholesterol scores could be assessed along with other blood markers.

Here's the bad news: regardless of which roast of coffee the participants drank, their total cholesterol scores increased. So did their LDL cholesterol (the bad cholesterol) and biomarkers of inflammation, which is thought to be linked to heart disease and cancer.

What this means for you

Coffee is still the single largest source of antioxidants in the Western diet, but this study suggests that it might not be the holy grail of beverages (or even the holy coffee cup). I should caution you, however, not to panic and throw away all of your coffee. This is a small study and the researchers themselves note that further large-scale research is needed. If you have poor cholesterol scores that are not otherwise responding to treatment (including diet, exercise, and medication), print out this Health & Nutrition bite and take it in to your doctor for discussion. She will be best equipped to tell you if cutting out coffee will make a difference for you.

First posted: July 3, 2013