Caffeine is the world’s most widely consumed psychoactive substance, with coffee serving as its primary source for centuries. Despite its long-standing popularity, opinions about its impact on health have been mixed for decades.
“Historically, coffee has had a bad reputation,” explains Marc Gunter, professor of cancer epidemiology and former head of nutrition and metabolism at the International Agency for Research on Cancer (IARC). “Research from the 1980s and 1990s suggested that coffee drinkers faced a higher risk of cardiovascular disease, but that perspective has shifted over time.”
With a growing body of large-scale studies conducted over the past decade, researchers now have access to data from hundreds of thousands of coffee drinkers. So, what does this data really reveal? Does coffee offer health benefits or pose risks?
Coffee has been linked to an increased cancer risk due to acrylamide, a potentially carcinogenic compound found in foods like toast, cakes, and chips. However, the IARC concluded in 2016 that coffee itself is not carcinogenic unless consumed at very high temperatures (over 65°C or 149°F). A 2023 review reinforced this conclusion, noting that while coffee is a primary source of acrylamide, there isn’t enough conclusive evidence to connect it to cancer risk. In fact, newer research suggests coffee might even offer protective benefits. Some studies have shown a lower risk of certain cancers in coffee drinkers.
Another concern revolves around caffeine and its potential link to miscarriage, particularly in the first trimester of pregnancy. However, experts caution that there is limited randomized data on this issue, and conclusions drawn from observational data may be unreliable.
“Women who drink coffee during pregnancy are typically older and more likely to smoke—both factors known to contribute to a higher risk of miscarriage,” says one researcher. “Additionally, women who experience nausea early in pregnancy are less likely to miscarry, and they tend to avoid coffee, which can exacerbate nausea. As a result, it’s possible that the women who aren’t drinking coffee are less likely to miscarry, skewing the data.”
As for the claim that coffee boosts productivity, Peter Rogers, a researcher on caffeine’s effects, argues that any benefits of coffee consumption on work efficiency are short-lived, as the body builds a tolerance to caffeine over time.
