The Darker the Coffee Roast, the Fewer the Health Benefits


Drinking coffee can give you a healthy dose of antioxidants, but you may want to select your roast carefully as not all java delivers the same benefits.

The longer coffee beans are roasted, the fewer beneficial health properties remain, according to a new study from researchers in South Korea. That means that dark-roast coffee, which is commonly found in cafes such as Starbucks and Peets, may confer fewer health benefits due to lost disease-fighting prowess, shows the study.

Credit: Frank Fox/Flickr, CC BY-SA 2.0

Assessing four levels of roasts — light, medium, city and French roast — the researchers discovered that the duration of roasting was tied to potential anti-inflammatory effects of the coffee beans.

“During roasting, major changes occur in the composition and physiological effects of coffee beans,” note the researchers in the Journal of Medicinal Food.

While the researchers don’t dispute the potential health benefits of a daily coffee, they found that “as the degree of roasting increases, the antioxidant property of coffee extract decreases.”

The new findings may leave you considering a lighter, softer brew if you’re seeking to maximize the plentiful health benefits that come alongside your daily caffeine infusion.

Related: Coffee’s Health Benefits Are Something to Buzz About

“When people think of coffee, they often associate the beverage with caffeine. However, coffee beans have many other chemicals that could help fight chronic inflammatory diseases,” says Dr. Sampath Parthasarathy, Editor in Chief of the Journal of Medicinal Food and Florida Hospital Chair in Cardiovascular Sciences and Interim Associate Dean, College of Medicine, University of Central Florida.

“Coffee drinkers are passionate about different roasts – light, medium and dark. This study suggests that some of the potentially beneficial compounds could be affected by the roasting process,” added Parthasarathy. “This article would certainly change my coffee roast preference!”

Coffee Up Close

Credit: Nick Webb/Flickr, CC BY 2.0

More than half of Americans drink coffee on a daily basis, with a yearly tab that exceeds $40 billion annually, according to data from Harvard Public Health. That could be good news for the health of millions, note the researchers.

“Coffee is a rich source of antioxidants that may contribute to prevention of oxidative stress-related diseases,” report the study authors, adding that “previous studies have shown that coffee has protective effects against oxidation and DNA damage in human cell models.”

Yet data on the effects of roasting has been lacking. Until now, that is. When the researchers assessed the health benefits of different roasts, they zeroed in on a compound known as chlorogenic acid, as well as other chemical properties tied to health benefits.

Related: Why You May Want to Drink Water Before Coffee in the Morning

“Chlorogenic acid is another well-known efficient antioxidant in coffee extract; it was highest in light roast coffee extract and highest with low roasting temperature and lowest in dark roasted extract. Carbohydrates, protein, and chlorogenic acid are all decreased in coffee during the roasting process,” write the researchers.

The decrease in these substances as coffee roasts occurs on a molecular level.

“The antioxidant capacity of coffee is attributed to the presence of polyphenolic compounds, and it is well understood that roasting affects the antioxidant properties of coffee. It is well known that roasting greatly affects the chemical composition of coffee extract due to the high temperature during roasting process,” report the study authors.

Ultimately, the study concludes that “the antioxidant property of coffee extracts is related to the amount of roasting, with a negative effect noted as the level of roasting increases.”