The short answer: current evidence does not show that coffee causes cancer

In 2016, the International Agency for Research on Cancer (IARC) removed coffee from its list of possible carcinogens. The agency had classified it as "possibly carcinogenic" in 1991, but decades of new research changed that conclusion. Today, major health organizations—including the American Cancer Society and the National Cancer Institute—do not identify coffee as a cancer risk factor.

What shifted was the evidence itself. Earlier studies suggested a link between coffee and certain cancers, but those studies had methodological problems: they did not account for smoking, alcohol use, or other factors that actually do increase cancer risk. When researchers controlled for these confounders, the apparent coffee-cancer connection disappeared.

Key Takeaways

  • Coffee was reclassified as safe by IARC in 2016 after review of over 1,000 studies found no causal link to cancer.
  • Early studies suggesting a coffee-cancer link failed to account for smoking and heavy alcohol use, which are actual cancer risk factors.
  • Some research suggests coffee may actually lower the risk of certain cancers, including liver and endometrial cancer.
  • Very hot beverages (above 65°C or 149°F) are classified as possibly carcinogenic, but this refers to temperature, not coffee itself.

Why the old studies seemed to show a link

In the 1980s and 1990s, several case-control studies reported associations between coffee consumption and cancers of the pancreas, bladder, and breast. These findings alarmed the public and led to the 1991 IARC classification. But the studies had a critical flaw: people who drank a lot of coffee were also more likely to smoke cigarettes and drink alcohol—both established carcinogens.

When researchers later conducted larger, better-designed studies that separated coffee use from smoking and alcohol use, the associations vanished. A person who drank five cups of coffee a day but did not smoke had no higher cancer risk than someone who drank no coffee. The earlier apparent link was confounding, not causation.

What the current research shows

Since the 2016 IARC reclassification, the body of evidence has only strengthened. Large prospective cohort studies—which follow people over time and are more reliable than case-control studies—have found no increased cancer risk from coffee consumption at any level.

Some research has even suggested protective effects. Studies have found associations between coffee consumption and lower risk of liver cancer, endometrial cancer, and melanoma. These associations are not yet proven causal, but they suggest coffee is not a risk factor and may offer some benefit. The mechanism is unclear; coffee contains hundreds of compounds, and several have antioxidant or anti-inflammatory properties that could theoretically reduce cancer risk.

The confusion about hot beverages

In 2016, the same year IARC cleared coffee, the agency classified "drinking very hot tea" as possibly carcinogenic. This created confusion because people thought coffee was being singled out. In fact, IARC was classifying the temperature of the beverage, not the beverage itself.

The concern is that liquids above 65°C (149°F) may cause repeated thermal injury to the esophagus, and chronic injury can increase cancer risk. This applies to any very hot drink—coffee, tea, or soup. It does not apply to coffee at normal drinking temperature. If you drink your coffee hot but not scalding, this classification does not affect you.

How much coffee is safe to drink

Health organizations do not set an upper limit on coffee consumption based on cancer risk, because no safe threshold exists—there is no level above which risk increases. The FDA suggests that healthy adults can consume up to 400 milligrams of caffeine per day, which is roughly four or five cups of brewed coffee, without adverse effects. This is a guideline about caffeine's effects on sleep and anxiety, not cancer.

Individual tolerance varies. Some people experience jitteriness, sleep disruption, or acid reflux at lower amounts. If coffee causes you physical discomfort, reducing your intake makes sense for your overall health—but not because of cancer risk.

Who should be cautious about coffee

Certain groups may want to limit coffee for reasons unrelated to cancer. Pregnant people are often advised to keep caffeine intake below 200 milligrams per day because high caffeine use has been associated with miscarriage in some studies. People with uncontrolled high blood pressure, certain heart arrhythmias, or anxiety disorders may find that caffeine worsens their condition. Those taking certain medications should check with their doctor, as coffee can interact with some drugs.

None of these cautions are about cancer risk. They reflect other health considerations that may apply to your situation.

What actually increases cancer risk

If you are concerned about cancer prevention, the evidence points to factors with much stronger associations: smoking, heavy alcohol use, obesity, physical inactivity, and certain infections. Reducing these risks will have far more impact on your cancer risk than your coffee consumption. The American Cancer Society recommends not smoking, limiting alcohol, maintaining a healthy weight, exercising regularly, and eating a diet rich in vegetables and whole grains.

Coffee can be part of a healthy diet. Some research suggests it may even contribute to overall health through its antioxidant content, though the evidence is still developing.

Frequently Asked Questions

Does decaffeinated coffee have different cancer risk than regular coffee?

No. The decaffeination process does not change the cancer risk profile. Both regular and decaffeinated coffee show no association with increased cancer risk in current research.

What about coffee with added ingredients like cream or sugar?

The additives themselves do not change coffee's cancer risk. However, very high sugar intake is associated with obesity, which is a cancer risk factor. If you add large amounts of sugar to coffee, the concern is the sugar itself, not the coffee.

If coffee might lower cancer risk, should I start drinking it?

The evidence that coffee lowers cancer risk is suggestive but not conclusive. If you do not drink coffee and do not want to, there is no reason to start based on cancer prevention. If you already drink coffee, you can continue without concern.

Is instant coffee or cold brew safer than hot brewed coffee?

All forms of coffee have the same cancer risk profile. The only temperature-related concern is drinking beverages that are scalding hot (above 65°C). Cold brew and room-temperature coffee carry no thermal injury risk.