Certain Kinds of Coffee Could Be Sabotaging Your Cholesterol -

On-demand coffee machines are becoming more common in the workplace, but new research suggests that drinking coffee brewed this way could contribute to higher “bad” cholesterol levels.

The oil in coffee beans is rich in compounds called diterpenes. Decades ago, scientists found that these substances were high enough in unfiltered coffee to strongly raise “bad” LDL cholesterol and slightly reduce “good” HDL cholesterol in humans.

Later research showed that diterpenes were significantly higher in unfiltered boiled and French press coffee than in paper-filtered coffee.

“Coffee from workplace machines, however, had not been examined until now,” says study author David Iggman, PhD, a researcher at Uppsala University in Sweden. “We found the levels of these substances are much higher in coffee from these machines than from regular drip-filter coffee makers.”

Based on their results, Dr. Iggman and colleagues estimated that replacing three cups of brewing-machine coffee with paper-filtered coffee five days per week could lower LDL cholesterol by 13 percent over five years, or 36 percent over 40 years.

Paper Filters May Make a Difference

For the analysis, the study authors measured two kinds of diterpene — cafestol and kahweol — in coffees made in 14 different types of conventional self-serve coffee makers found in break rooms and different work spaces.

Coffee samples were taken from two types of office machines:

Machines that mixed hot water with the ground coffee and then passed the liquid through a metal filter
Machines that mix a liquid coffee concentrate with hot water

For comparison, the researchers also analyzed samples of coffee made with a paper filter, a percolator, and a French press, as well as by coffee made by boiling ground beans with water (a method popular in Sweden).

In addition, they examined four espresso samples made in three cafeterias and one laboratory workplace coffee machine.

They discovered that most coffees from workplace brewing machines contain higher diterpene concentrations than paper-filtered coffee.

Ranking Brew Styles From Best to Worst

The researchers measured diterpenes in terms of milligrams per liter (mg/L). For all workplace coffee machines, the median range of cafestol and kahweol was 174 and 135 mg/L, respectively, compared with 11.5 mg/L of cafestol and 8.2 mg/L for kahweol in paper-filter drip coffee.

Diterpene concentrations in French press (87 mg/L cafestol and 69 mg/L kahweol) and percolator coffee (91 mg/L cafestol and 69 mg/L kahweol) fell in the middle between coffee machine and paper filter levels.

Boiled coffee (939 mg/L cafestol and 678 mg/L kahweol) and espresso (1,059 mg/L cafestol and 621 mg/L kahweol) had the highest diterpene content. The study authors noted, however, that there was considerable and “unexplained” variation in espresso samples with cafestol levels ranging from 35.6 to 2,446.7 mg/L.

Because espresso is made by forcing hot water through very finely ground coffee under high pressure without a filter, it makes sense that this brew has the highest potential to raise cholesterol levels.

The findings here correspond with previous research showing a significant association between espresso consumption and higher measure of bad cholesterol in the blood.

“Keeping espresso to a minimum will lower risks,” says Melissa Prest, DCN, RDN, a spokesperson for the Academy of Nutrition and Dietetics, who was not involved in the study. She recommends limiting espresso to one or two shots per day at most.

Overall, coffee brew styles ranked as follows in order of best to worst for cholesterol are:

Paper filter
Filtered boiled
French press
Workplace coffee machine
Percolator
Boiled without filtering
Espresso

Study Does Not Address the Impact on Heart Disease Risk

For Gregory Katz, MD, a cardiologist at NYU Langone Heart in New York City, these study results are limited in that experiments were not conducted to see the actual impact on LDL levels or endothelial function (the functioning of cells that line the inside of blood vessels).

“They certainly didn’t test different brewing methods and then see how that impacted things like heart attack and stroke,” says Dr. Katz. “The study tells us zero information about how this impacts the risk of cardiovascular disease.”

Coffee Has Many Health Benefits

While cafestol and kahweol in excess may raise LDL cholesterol, research suggests that these compounds may also come with benefits. “The benefits of these two substances with regular consumption of coffee includes anti-inflammatory properties and its links to reducing the risk of type 2 diabetes,” says Julia Zumpano, RD, with the Cleveland Clinic Center for Human Nutrition, who was not involved in the new study.

She adds that the negative effects may be significantly lowered through filtering.

Coffee also offers the following health benefits:

Micronutrients like vitamin B2 and B3, potassium, and magnesium
Antioxidants, which protect cells from damage and may lower the risk of certain cancers
Phenols, which play key roles in immunity and protecting the body from inflammation
Caffeine, which may offer potential support for brain health, blood flow, and blood pressure.

Coffee Add-Ins May Pose a Higher Risk Than Coffee Itself

Maya Vadiveloo, PhD, RD, chair of the American Heart Association’s Lifestyle Nutrition Committee and an associate professor of nutrition and health sciences at the University of Rhode Island in Kingston, suggests that the ingredients we add to coffee may be more damaging than the coffee itself.

“Both excess added sugar and saturated fat found in high fat dairy products like cream adversely affect cardiovascular health,” says Dr. Vadiveloo, who was not involved in this study.

She advises consumers to drink coffee in moderate amounts, but filter it whenever possible to reduce the risk of elevated LDL cholesterol.

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