August 11, 2026, 4 min read

Science may finally have made up its mind about coffee’s health benefits

Doctors used to warn coffee drinkers. Now research reassures them

By Mary Randolph edited by Sarah Lewin Frasier & Allison Parshall

When Farin Kamangar was training as a physician in the 1980s, he asked patients about three lifestyle factors that could affect their health: alcohol, smoking and coffee. Though coffee didn’t have the same associations as smoking or drinking, Kamangar says, “the connotation was that this is not a good thing.”

Recently, though, coffee drinkers keep getting good news.

In 2026 alone, studies across disciplines have found that coffee could reduce dementia risk, protect your liver and improve your gut microbiome. Last year the U.S. Food and Drug Administration labeled black coffee as “healthy.” Kamangar, now an epidemiologist at Morgan State University, co-authored a 2025 literature review that drew on more than 100 studies and concluded “that moderate coffee intake is more beneficial than harmful across a wide range of health outcomes.”

Just a few weeks ago the American Heart Association (AHA) confirmed the beverage’s lack of harm—and its potential benefit—to heart health. Drinking up to five cups of caffeinated coffee a day, its authors wrote, has been linked to a lower risk of heart attack, diabetes, stroke and irregular heartbeat.

Gregory Marcus, a cardiologist at University of California, San Francisco, and lead author of the AHA statement, says his team has been “shocked” by the number of apparently positive effects of caffeinated coffee that scientists have found over the years.

“It’s remarkable how protective it is,” he says.

Coffee is the most consumed beverage in the U.S., with about two thirds of adults drinking it daily. People have been drinking coffee for centuries, and scientists have been studying its health effects for nearly as long. (Persian physicians were discussing coffee’s medicinal properties in the 900s C.E.!) Systematic studies of the relationship started back in the late 1940s. So, why does the research keep changing?

According to geneticist Marilyn Cornelis, scientists are simply conducting research better. Cornelis, who studies the genetics of how we metabolize caffeine at Northwestern University, first became interested in the subject two decades ago because of how many “inconsistencies” the research had. In the 1970s and 1980s, several studies found negative relationships between coffee and health, including a popular 1981 paper that found an association between coffee drinking and pancreatic cancer. The study interviewed around 1,000 patients at a hospital and found that those with pancreatic cancer drank more coffee—but many members of the control group had other medical issues that prevented them from drinking coffee at all. Subsequent studies, including one by the same research team, failed to replicate the results.

Read more: Has science finally made up its mind about coffee’s health benefits? – Scientific American

Continue/Read Original Article: Has science finally made up its mind about coffee’s health benefits? | Scientific American