As many as 80 percent of Americans consume some form of caffeine every day, whether in the form of coffee, soft drinks, tea, chocolate or medications with added caffeine, according to the U.S. Food and Drug Administration. The average amount ingested each day is around 200 mg --- about two 5-oz. cups of coffee or four sodas. But what's average may not be good for you, especially if you have a heart condition or other health problems, such as panic attacks or anxiety.
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Caffeine acts as a central nervous system stimulant, which causes increased alertness and ability to concentrate at low levels. The stimulant may also help reduce migraines and potentiates the actions of pain relievers, which is why it's often paired with acetaminophen or aspirin in pain relievers. Caffeine is also used as a stimulant for premature babies who sometimes "forget" to breathe. By contrast, it can also increase urination, leading to diuresis, or excess fluid excretion through the kidneys. Caffeine can also raise your blood pressure, speed up your metabolism and relax smooth muscle.
Recommendations
According to MayoClinic.com, doses of 200 to 300 mg per day of caffeine aren't harmful for most people. If you consume 500 to 600 mg per day, you may have an increase in side effects, and the FDA warns that 600 mg per day is too much. People who don't normally drink caffeine might have side effects on even 200 mg per day. Men tend to be more sensitive to side effects of caffeine than women. Pregnant women should limit their caffeine intake to 300 mg per day, according to Drugs.com; higher doses may increase the risk of miscarriage, interfere with fetal growth or cause fetal heart problems.
Side Effects
The side effects of too much caffeine are well documented and include nervousness, jitteriness, shakiness, inability to sleep, anxiety, irritability, fast or pounding heartbeat, headaches, diarrhea, stuffy nose, muscle tension, dizziness and stomach upset.
Risks
In very high doses, caffeine can be deadly, but levels likely to cause severe side effects are hard to consume just by drinking soft drinks of coffee. Taking pills containing caffeine can cause dangerously high levels of the stimulant; a single caffeine tablet contains as much caffeine as one to three 5-oz. cups of coffee, the FDA reports. People with liver disease should limit their caffeine intake because the liver may not excrete it well, increasing the risk of side effects.
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