Safe Daily Caffeine Intake for Adults
For healthy adults, a safe daily caffeine intake is ≤400 mg per day, which is not associated with adverse cardiovascular effects, behavioral effects, reproductive/developmental effects, or bone status issues. 1
Population-Specific Safe Caffeine Limits
- Healthy adults should limit caffeine intake to ≤400 mg daily (equivalent to 3-5 cups of coffee), as recommended by the FDA and European Food Safety Authority 1
- Pregnant women should limit caffeine intake to ≤200-300 mg/day due to slower caffeine metabolism during pregnancy and the fact that caffeine freely crosses the placenta 1, 2
- Children and adolescents should limit caffeine to <2.5 mg per kg of body weight daily, which is approximately equivalent to 1-2 cups of tea or 1 small cup of coffee daily 3, 1
- Elderly individuals with hypertension or cardiovascular concerns should limit caffeine intake to <300 mg/day and avoid it completely if they have uncontrolled hypertension 1
Caffeine Content in Common Sources
- Coffee contains 50-300 mg per 8 oz (237 mL) serving, depending on bean type, roasting method, and brewing technique 1
- Tea contains 15-50 mg per 8 oz (237 mL) serving 1
- Decaffeinated coffee/tea contains approximately 10 mg or less per 8 oz (237 mL) 1
- Carbonated soft drinks have variable caffeine content and contribute about 17% of total caffeine intake in the general population 1
Potential Risks of Excessive Caffeine Consumption
- Exceeding the recommended 400 mg daily limit may lead to adverse effects such as agitation, anxiety, or sleep disturbance 1
- Caffeine withdrawal symptoms can occur when regular consumption is stopped, including headache, fatigue/drowsiness, irritability, difficulty concentrating, and nausea 4
- Lethality may occur after acute consumption of 10 g caffeine, an amount well above what is attainable in coffee and tea beverages 3, 1
Special Considerations
- Individuals with pre-existing conditions should exercise caution with caffeine consumption above 400 mg/day 1
- Current average caffeine intake in European countries ranges from 280-490 mg daily, with the highest consumption in Scandinavian countries 5
- Tea consumption in the UK (2-3 servings daily) fits well within safe limits, and consumption could rise to 8 servings daily and still be within safe guidelines 6
- For moderate coffee consumers (3-4 cups/day providing 300-400 mg/day of caffeine), there is little evidence of health risks and some evidence of health benefits 7
Important Caveats
- Individual responses to caffeine can vary based on metabolism, which depends on many endogenic and environmental factors 5
- Smokers tend to consume more caffeine than non-smokers, as do persons with certain mental illnesses 5
- Caffeine content in coffee and tea beverages varies greatly depending on the brewing method, and content in energy drinks can also vary significantly 5
- While mean caffeine intakes are generally within recommended safe levels, heavy consumers in certain subpopulations might benefit from dietary advice 8