Moderate coffee intake (up to 400 mg) linked to lower cardiovascular and diabetes risk

The American Heart Association (AHA) has reassessed existing evidence and concludes that moderate coffee consumption—up to 400 milligrams of caffeine per day—is safe for most healthy adults and is associated with a lower risk of cardiovascular disease and type 2 diabetes.

According to the AHA's calculations, 400 mg roughly corresponds to three to five cups of black filter coffee of about 240 ml each, although cup counts are only an approximation. The European Food Safety Authority (EFSA) estimates that 200 ml of filter coffee contain about 90 mg of caffeine, while a 60 ml espresso contains roughly 80 mg.

Pregnant women are advised to limit caffeine to a lower threshold: EFSA recommends a maximum of 200 mg per day in pregnancy. People with existing medical conditions, those taking medications, or individuals who are particularly sensitive to caffeine should consult a physician for personalised advice. Short-term effects of caffeine can include higher heart rate and blood pressure and, in sensitive people, palpitations or restlessness.

"Coffee is a pleasure, not a medicine," said Omar Hahad of the Cardiology Centre at University Medicine Mainz, reflecting the view that the beverage should not be treated as a therapeutic intervention.

What the studies show

Much of the long-term evidence comes from observational studies, which can detect associations but cannot prove cause and effect. Gregory Marcus, lead author of the AHA report, warned that "The way people metabolise coffee varies substantially from person to person. Therefore you should listen to your own body. If you tolerate one cup well, you do not need to force yourself to drink three."

Research linking coffee to a lower risk of type 2 diabetes has been consistent. Matthias Schulze of the German Institute of Human Nutrition in Potsdam-Rehbruecke noted that reductions in diabetes risk have been observed even for decaffeinated coffee; in some analyses, people who drank six cups a day had about a 33 percent lower risk of developing type 2 diabetes compared with non-coffee drinkers. This points to non-caffeine components—such as chlorogenic acids and other plant compounds—as possible contributing factors.

Concerns have also been raised about pesticide residues in coffee beans. Jens Schubert of the German Federal Institute for Risk Assessment (BfR) emphasised that "The mere detection of pesticide residues does not automatically mean the product is dangerous for consumers. Risk assessment analyses the potential hazard in relation to the amount a consumer may ingest." Current data do not indicate a consumer health risk, although roughly two to three percent of tested raw coffee samples have exceeded regulatory limits and are typically removed from the market.

In summary, for most healthy adults moderate coffee intake up to 400 mg of caffeine daily appears safe and is associated with some health benefits. However, the AHA stresses that this should not be interpreted as a recommendation to start drinking coffee for preventive health. As Hahad put it, "For most people coffee is primarily an enjoyment, not a medicine or a dietary supplement." Adequate sleep, a balanced diet and regular physical activity remain the proven foundations of health.

Photo: press material from the event