Myth or fact

Is coffee bad for you?

Short answerNo

By GyroscopeUpdated November 15, 20268 sources

No. When researchers pulled together 201 meta-analyses on coffee in 2017, it went with benefit far more often than harm, with the biggest drop in risk at three to four cups a day. The harms that held up were in pregnancy and, for women, a higher risk of fractures. The rest of the risk is in what you add to coffee and when you drink it.

The belief has deep roots. Your parents may have told you coffee would stunt your growth, your doctor may have told you to cut back for your heart, and in 1991 the World Health Organization’s cancer agency called it “possibly carcinogenic”. It also feels like a drug, because it is one. Skip a day and you get a headache.

Where the bad name came from

Old studies made coffee look deadly, and the reason turned out to be cigarettes. In the NIH-AARP study of 402,260 Americans aged 50 to 71, coffee drinkers looked more likely to die until the researchers accounted for the fact that they also smoked more. After that the result reversed. Men drinking 4 to 5 cups a day had a 12% lower risk of dying over 13 years, and women 16% lower. It held in people who had never smoked.

The cancer label went the same way. In 2016 the cancer agency had 23 scientists review more than 1,000 studies, and they took coffee out of the “possibly carcinogenic” group. They found no conclusive evidence that coffee causes cancer, no effect on pancreas, breast or prostate cancer, and lower risks of liver cancer and cancer of the lining of the womb. What they did flag was very hot drinks of any kind, above 65°C (149°F).

What the evidence shows now

Blaming coffee for the things that come with it is like blaming the bread for the bacon in a sandwich. Black coffee, or coffee with very little sugar and cream, went with a 14% lower risk of dying in a 2025 study of 46,000 Americans, and heavily sweetened coffee didn’t. Decaf drinkers in the UK Biobank had lower death rates too, which suggests much of the good comes from parts of coffee other than caffeine.

The heart. In the UK Biobank, each extra daily cup went with a 3% lower risk of heart rhythm problems in 386,258 people. In a 2023 trial at UC San Francisco, 100 adults were told at random each day to drink coffee or skip caffeine. Coffee days didn’t bring more of the extra beats from the top of the heart the researchers were watching for. They did bring more steps, more extra beats from the lower chambers, and 36 minutes less sleep.

Dehydration. In 50 men who drank coffee every day, four cups a day kept them as hydrated as the same amount of water. Does coffee dehydrate you? has the study.

Where coffee can hurt

Coffee still has costs, in a few places.

• Pregnancy, where high intake went with lower birth weight and pregnancy loss. Keep it under 200 mg a day.
• Fractures in women, where the 2017 review found a link that wasn’t there in men.
• Unfiltered coffee, like French press or boiled coffee, which raises LDL cholesterol. A paper filter fixes it.
• Sugar and cream, which seem to cancel out the benefit when there’s a lot of them.
• The late cup, since half of it is still in you 5 hours later, and deep sleep pays for it.

Where the real risks are goes through each, and is coffee healthy? has the studies and their limits. The cutoff clock handles the late cup.

What we’d tell a friend

If you like coffee, drink it. Keep it close to black, use a paper filter if you have a lot, have the big cups in the morning, and stay under about 400 mg a day. These are studies that watch people, so they can’t prove coffee is the reason its drinkers do well. But the biggest of them keep finding coffee drinkers doing as well as everyone else, or better.