What is caffeine?
Caffeine is a natural stimulant found in various plants, including coffee beans, tea leaves, and cocoa beans. It belongs to the methylxanthine class of compounds and acts on the central nervous system, primarily as an adenosine receptor antagonist. This means that it blocks the action of adenosine, a neurotransmitter that promotes relaxation and drowsiness in the brain, leading to increased alertness and wakefulness.
What effects does caffeine have on the body?
After ingestion, caffeine is quickly absorbed from the gastrointestinal tract into the bloodstream. Once it’s in the bloodstream, caffeine promptly gets absorbed into body tissues and crosses over multiple barriers in the body, including the blood-brain barrier (a roadblock between your bloodstream and your brain which is there to protect your brain from toxins), the blood-placenta barrier for pregnant ladies, and the blood-testis barrier for men. Caffeine peaks in the blood anywhere from 15 minutes to 2 hours.
Caffeine is considered a drug because of its stimulant effects on the nervous system. It has been found to positively influence mental performance, increase energy, and improve mood.
Other benefits of caffeine consumption include improved mental alertness, speed reasoning, and memory, weight loss, improved physical performance during endurance exercise, and protection against certain skin cancers.
Negative side effects associated with caffeine include nervousness, anxiety, sleeplessness, irritability, dehydration, stomach upset, diarrhea, and nausea, increased heart rate, and both psychological and physical dependence.
What are the tolerable limits?
In adult men and non-pregnant women, the U.S. Food and Drug Administration considers 400 milligrams (about 4 cups of brewed coffee) a safe amount of caffeine for healthy adults to consume daily.
Pregnant women should limit their caffeine intake to 200 mg a day (about 2 cups of brewed coffee), according to the American College of Obstetricians and Gynecologists.
For comparison:
8 oz of coffee contains 100 mg of caffeine
8 oz of green tea contains 35 mg of caffeine
a can of soda contains anywhere from 40-72 mg of caffeine
Energy drinks can range from 20-400mg+ of caffeine (yes, per drink!)
and caffeine content of drugs varies from 16 mg to 200 mg per tablet
How to decide how much caffeine is right for you
People have different tolerances and responses to caffeine, partly due to genetic differences.
Take inventory of how you feel when you drink something caffeinated, and decide for yourself what makes sense.
If you feel jittery, anxious, or addicted to the rush, then perhaps you should pull back on the caffeine and opt for a chemical-free decaf coffee or naturally uncaffeinated herbal tea. If you’re ultimately feeling better with less, then follow your body’s cues.
Keep in mind that not all caffeinated products are created equal! Opting for organic, whole-food sources of caffeine, like coffee, tea, or cacao is going to provide other additional nutrients that will benefit your body.
In general, it’s smart to avoid sodas, energy drinks, and other highly processed items with artificial sources of caffeine— as they are unnatural and can cause inflammation and other negative side effects.
