Most of us like caffeine. This popular drug is a stimulant to the nervous system and can change your mood from one of drowsiness to being alert. It's a good thing we can use caffeine in drinks like coffee, tea and soda; it tastes quite bitter in its natural state.
Caffeine content varies by drink. Coffee tends to have the highest amount of caffeine per serving. Brewed generic coffee, for example, ranges from 102 to 200 milligrams per eight-ounce cup. Instant coffee comes in at around 90 milligrams.
Many sodas contain caffeine in the 20 to 50 milligram range. There are some that are higher, with Red BullR, JoltR and Mountain DewR having the highest amounts.
Tea tends to be at the lower end of the spectrum. Black tea, for example, contains between 14 and 61 milligrams of caffeine. Green tea is a little lower, at 24 to 40 milligrams. Instant tea comes in at 26 milligrams.
Some people are more sensitive to caffeine than others. If you're susceptible to the effects of caffeine, just small amounts-even one cup of coffee or tea-may prompt unwanted effects, such as restlessness and sleep problems.
How you react to caffeine may be determined in part by how much caffeine you're used to drinking. People who don't regularly drink caffeine tend to be more sensitive to its negative effects. Other factors may include body mass, age, medication use and health conditions such as anxiety disorders. Research also suggests that men are more susceptible to the effects of caffeine than women.
It's difficult to say just how much caffeine is too much. Each of us has a unique physiological makeup. If you drink more than 500 milligrams a day, it might be a good idea to cut back. Symptoms of overuse include jitteriness, anxiety, irritability, an upset stomach and muscle tremors.
Evidence of the long-term harm in using caffeine has not been established. Coffee, for example, has a mild diuretic effect. However, if you drink it moderately, you don't need to worry about increasing other fluids.
Two groups who should avoid caffeine are pregnant women and individuals with high blood pressure. Caffeine also interferes with some antibiotics as well as some asthma medications.
If you're experiencing low energy during the day, it's possible it may be because you're using too much caffeine. Another possible sign is if you're experiencing insomnia, though people who use a lot of caffeine often experience less trouble sleeping than those who don't use it very much.
If you want to cut back on your caffeine intake, it's best to do it slowly. If you cut back to zero, you're likely to experience strong withdrawal symptoms such as a bad headache, fatigue and irritability.
Tea may be a healthy way to cut back on caffeine without cutting it out completely. Black and green teas contain flavonoids. These ingredients are antioxidants found in high doses in these teas. Some studies have said that green and black teas have as many antioxidants as fruit and vegetables.
Tea also contains minerals that are good for your body, such as zinc, potassium and manganese. Scientists are conducting studies to see if they reduce the risk of coronary heart disease.