Coffee: benefits, limits and who should cut back

Updated November 14, 2026 Six Habits Editorial Team

A woman drinking her morning coffee by the window, a coffee pot on the table

The short answerAn umbrella review of more than 200 meta-analyses found that moderate coffee drinking, about 3 to 4 cups a day, is more often linked to benefit than harm, including lower mortality. The exceptions are pregnancy and women at higher risk of fractures. The FDA considers up to 400 mg of caffeine a day generally safe for healthy adults.

Key points

3 to 4 cups of coffee a day are linked to lower all-cause mortality.
Coffee is more often linked to benefit than harm.
During pregnancy, limit caffeine to 200 mg a day.
Avoid coffee late in the day: it disrupts sleep.

What the research shows

Umbrella review. An analysis of 201 meta-analyses of observational studies and 17 of clinical trials found that coffee was more often linked to benefit than harm. The largest reduction in relative risk of death from any cause was seen at 3 to 4 cups a day, and coffee was also linked to lower risk of cardiovascular disease, several cancers and liver disease (Poole et al., 2017).

Safety. A systematic review of caffeine safety concluded that up to 400 mg a day is not linked to adverse effects in healthy adults, and up to 300 mg a day in healthy pregnant women (Wikoff et al., 2017). U.S. obstetricians (ACOG) advise staying under 200 mg a day during pregnancy.

Sleep. A meta-analysis found that caffeine shortened total sleep by about 45 minutes and lowered sleep efficiency. To avoid that effect, it recommended a cutoff about 8.8 hours before bedtime for a standard cup of coffee (Gardiner et al., 2023).

Who should cut back

pregnant women;
people with anxiety, insomnia or palpitations;
women at higher risk of fractures;
people with uncontrolled high blood pressure.

In practice

Count all sources: coffee, tea, soda, energy drinks, pre-workout supplements.
Have your last cup by early afternoon.
Skip the syrups and whipped cream: a sweetened coffee drink can contain as much sugar as a can of soda.

Frequently asked questions

How much caffeine is in a cup of coffee?

An 8-ounce cup of brewed coffee has about 80 to 100 mg. Large coffee-shop drinks can contain 300 mg or more.

Does decaf have the same benefits?

Many studies found similar associations for decaf, suggesting that compounds other than caffeine play a role.

Sources

Poole et al. (2017). Coffee consumption and health: umbrella review of meta-analyses of multiple health outcomes. BMJ :j5024. doi:10.1136/bmj.j5024
Wikoff et al. (2017). Systematic review of the potential adverse effects of caffeine consumption in healthy adults, pregnant women, adolescents, and children. Food and Chemical Toxicology 109:585-648. doi:10.1016/j.fct.2017.04.002
Gardiner et al. (2023). The effect of caffeine on subsequent sleep: A systematic review and meta-analysis. Sleep Medicine Reviews 69:101764. doi:10.1016/j.smrv.2023.101764

Prepared according to our evidence methodology and the principles of lifestyle medicine. For education only; it does not replace advice from your doctor.

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Coffee: benefits, limits and who should cut back

Key points

What the research shows

Who should cut back

In practice

Frequently asked questions

Sources

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