Caffeine is produced by plants as an insecticide. Over 60 plants produce it to fight off insects. For human consumption, we concentrate the caffeine, either through extraction (coffee brewing) or add it directly (sodas and other foods). When taken in these unnaturally high amounts, caffeine has the typical effects of any drug, both beneficial and harmful.
Beneficial effects
Caffeine increases the absorption and distribution of some analgesics in the brain. This makes it a useful additive for some headache medications. It also has vasoconstrictive properties which can help reduce some forms of headache directly.
Caffeine increases alertness and fights off fatigue. This is the most popular use. With continued use, this goes away along with any benefit.
Caffeine can help alleviate symptoms of asthma, although many other drugs work much better.
While there is evidence that coffee can help with some medical conditions (reducing the incidence of diabetes and some cancers) this is probably not due to caffeine but other ingredients. One exception seems to be a reduction in Parkinson’s disease in men. According to Harvard Medical1, the sex difference may be related to how men and women metabolize caffeine differently.
Harmful effects
Although caffeine is used in weight loss because it has a diuretic property, any weight loss is temporary and using caffeine in this manner can lead to dehydration. In fact, caffeinated beverages usually lead to more water loss than the amount in the beverage. The result is that a caffeinated cola may temporarily quench thirst, but then lead to more thirst (from water loss) later on.
Caffeine crash - This is the inevitable downside of using caffeine to stay away or alert longer than normal. The body’s reserves are depleted and a sudden, overwhelming fatigue can hit. For those using caffeine to stay awake while driving, the “crash” can be a fatal side effect.
Increased heart rate and blood pressure - For those who are at risk for stroke or cardiac problems, coffee and caffeine may be life threatening. Most doctors will recommend a reduction or elimination of caffeine in these patients.
Insomnia and tremor are dose dependent, but they may appear in susceptible people even at ‘normal’ intake levels.
Caffeine is a psychoactive compound. It can trigger anxiety attacks in those who are at risk.
Although coffee as a remedy for drunkenness is a myth, caffeine can keep someone drinking longer before they succumb to alcohol. This combination can lead to alcohol poisoning as more alcohol is consumed beyond the point where someone would normally pass out.
References
- Harvard Medical: Coffee Health Benefits
