Your Daily Coffee and Your Health

For many people, the day starts with coffee. It is one of the most studied drinks in the world, and the news about it has gotten better over time. Here is a look at what large reviews say about a daily cup, and where the caveats lie. This is general education, not medical advice.

A review of reviews

In 2017, Poole and colleagues published an “umbrella review” in the BMJ, which gathers the findings of many meta-analyses. They pooled 201 meta-analyses of observational studies, covering 67 health outcomes, plus 17 meta-analyses of trials, covering nine outcomes. Across these, coffee was more often linked to benefit than harm.

• Largest benefit at moderate amounts. The biggest reductions in risk showed up around three to four cups a day compared with none, not at the highest intakes.
• Lower risk of death. For three to four cups a day versus none, the summary estimate for death from any cause was a relative risk of 0.83, about 17 percent lower, with a 95 percent interval of roughly 0.79 to 0.88.
• Heart health. Cardiovascular disease had a relative risk of about 0.85 and cardiovascular death about 0.81 at the same intake.

The fine print

• Association, not proof. Most of the evidence is observational. People who drink coffee may differ in other ways, so the authors could not show that coffee caused the benefit. They also did not recommend drinking coffee to prevent disease.
• It depends on the person. Caffeine can cause jitters, a faster heartbeat, trouble sleeping or stomach upset in some people. Caffeine advice during pregnancy is different, so ask your clinician if that applies to you.
• What goes in the cup counts. Studies of coffee are about coffee, not sweetened drinks with syrup, cream and whipped topping, which can add a lot of calories and sugar.

How much caffeine is a lot?

The U.S. Food and Drug Administration says that up to about 400 milligrams of caffeine a day, roughly four or five cups of brewed coffee, is generally not associated with dangerous effects for healthy adults. Sensitivity varies, and caffeine also comes from tea, soda, energy drinks and some medications.

Coffee and weight

Coffee has few calories on its own, and a morning cup can be part of a routine that you enjoy. It does not replace sleep or activity. If caffeine late in the day keeps you awake, it can work against you, because short nights affect appetite, as we describe in our sleep and weight guide. Our look at apple cider vinegar and zero-calorie sweeteners covers other things people add to their routines.

Ways to enjoy it

• Time it. Many people stop caffeine six or so hours before bed.
• Watch the extras. Check the numbers on sweetened drinks using the tips in our nutrition label guide.
• Listen to your body. If coffee causes palpitations or anxiety, cutting back is reasonable.

Sources

• Poole R, Kennedy OJ, Roderick P, Fallowfield JA, Hayes PC, Parkes J. Coffee consumption and health: umbrella review of meta-analyses of multiple health outcomes. BMJ, 2017;359:j5024 (figures from the abstract; check the paper for exact intervals).
• U.S. Food and Drug Administration. Consumer guidance on caffeine intake for healthy adults.