The pros and cons of caffeine
For most of us, caffeine is part of our daily lives, whether it’s a cup of java to get us going in the morning or a diet soda on our afternoon break. It can be a great pick-me-up, as 200 mg of caffeine has been shown to improve alertness and has comparable effects to taking a 20-30 minute nap.
However, as with all potentially good food and drinks, there’s such a thing as too much caffeine. There are no official guidelines, but the American Medical Association Council on Scientific Affairs defines “moderate” caffeine intake to be about 250 milligrams per day. For reference, here’s how some of your favorite caffeinated beverages measure up:
- Coffee and tea: One cup of brewed coffee has about 60-120 milligrams of caffeine, and one cup of white, green, or black tea has about 20 to 80 milligrams of caffeine.
- Soft drinks: The caffeine limit for a 12-ounce soft drink is 71 milligrams per 12 ounces.
- Energy drinks: The caffeine in energy drinks can exceed 200 milligrams per serving. It is easy to be misled by the heavy caffeine content in small drinks — or the number of servings in a container — and inadvertently consume too much.
Side effects of too much caffeine
While a cup of coffee or two per day can keep you refreshed, consuming more than 300 milligrams of caffeine in a day can increase your risk of nausea, anxiety, sleeplessness, restlessness and other side effects. The milder adverse effects of caffeine include palpitations, tremor, agitation, heartburn, headaches, and diarrhea, and the following severe effects have been reported with doses of caffeine exceeding 480 milligrams a day:
- Arrhythmias (heart rhythm disturbances)
- Rapid heart rate
- Cardiac ischemia (reduced blood flow and oxygen to the heart)
- Seizures
- Hallucinations
- Muscle breakdown (rhabdomyolisis)
- Death
It’s important to be aware that if you drink three or four cups of coffee within a short period of time, you could potentially put yourself at risk, so drink up, but in moderation.