Soda, tea, coffee and several energy drinks share a key ingredient: caffeine. Caffeine is a plant product that has a stimulating effect on our central nervous system. It blocks adenosine (a molecule that makes us tired), and triggers the body to produce epinephrine- also known as adrenaline. Caffeine causes the heart to beat faster which leads to increased alertness and feeling less tired. Typically, the "energy" effect of caffeine peaks about 1 hour after consumption and lasts about 2-3 hours.
A safe, moderate dose of caffeine is considered up to 250 mg a day; the equivalent of two 6-oz cups of coffee, or four 12-oz sodas.
Common side effects of caffeine include:
- More rapid breathing
- Increased heart rate
- Irregular heart beat
- Increased body temperature
- Increased blood flow to the skin and extremities
- Increased blood pressure
- Increased blood sugar levels
- Increased stomach acid secretion, heartburn or reflux
- Increased production of urine (caffeine is a diuretic)
More detrimental side effects can result from consuming 1000 mg or more of caffeine per day; the equivalent of ten 6-oz cups of coffee.
Additional side effects from consuming larger amounts of caffeine include: dizziness, hypoglycemia, fruit-like breath odor, troubled breathing, muscle tremors, nausea, diarrhea, increased ketones in urine, drowsiness, thirst, anxiety, confusion, irritability, insomnia, changes in appetite, dry mouth, blurred vision, and cold sweats.
Consuming larger amounts of caffeine on a regular basis may be linked to conception problems, increased episodes of heartburn, and changes in bowel habits. Over time, it can also lead to sleep deprivation, emotional fatigue, mood depression and anxiety-related feelings like excessive nervousness, sweating and tremors.
The effect of caffeine varies from person to person. Some people can have large amounts of caffeine without any bad effects, while others aren't able to handle even small amounts of caffeine. Decaffeinated beverages are a great alternative for people who dislike the more annoying side effects of caffeinated beverages, like sleeplessness or "the jitters". Also, people who take medications for depression, anxiety or insomnia, high blood pressure or other heart problems, chronic stomach upset or kidney disease should avoid caffeine until discussing the matter with a clinician.