Caffeine is a drug and food additive that is either naturally produced in certain plants or synthetically made by man. Caffeine is able to temporarily improve alertness, provide an energy boost and elevate mood, according to TeensHealth.org. Found in some pain relievers, tea, coffee, chocolate and certain soft drinks, caffeine is a common ingredient in an American diet.
Caffeine and Adenosine
Caffeine is most often used to combat drowsiness and increase alertness. Typically, drowsiness is caused by a buildup of adenosine in the brain. Caffeine prevents adenosine from binding in the brain and thus reduces drowsiness. The reduced amount of adenosine leads to increased brain activity, which in turn, causes the release of adrenaline, a hormone responsible for your body's flight-or-fight response.
Caffeine and Dopamine
Dopamine is a transmitter in the brain that performs a variety of functions, including activation of the brain's pleasure center. Caffeine increases dopamine levels and, thus, causes excess stimulation of your pleasure center. This increase in pleasurable sensation often makes you more alert. However, activation of your brain's pleasure center can cause you to crave caffeine and lead to a physical dependency on the drug.
Caffeine and the Cardiovascular System
A combination of hormones and nervous system control regulates your cardiovascular system. Caffeine activates the sympathetic nervous system, which, in turn, stimulates your cardiovascular system. This stimulation leads to an increase in heart rate and blood pressure. This sudden elevation in your cardiovascular levels also makes your more alert.
Dosage and Side Effects
In moderate amounts, caffeine is considered safe. KidsHealth.org notes that moderate use for adults is about 200 to 300 mg per day. However, teenagers and younger children should ingest only 100 mg of caffeine each day. More than 100 mg of caffeine per day often leads to a physical dependency on the drug. Physical dependency exposes you to withdrawal symptoms when you stop taking caffeine. Side effects of caffeine include anxiety, depression, insomnia, restlessness and tremors, according to MedlinePlus, a service of the National Institutes of Health. Caffeine often causes gastrointestinal side effects such as nausea and vomiting. Caffeine may interfere with you body's ability to absorb calcium, which in the long term can lead to decreased bone density and osteoporosis.
Member Comments