Fitness Facts: Caffeine
By Connie Colbert
Director, Canyon Health and Wellness Clinic
What is caffeine and how does it affect the body?
According to the U.S. National Library of Medicine, caffeine is a bitter substance that occurs naturally in more than 60 plants, including:
- Coffee beans
- Tea leaves
- Kola nuts, which are used to flavor soft drink colas
- Cacao pods, which are used to make chocolate products
There is also synthetic (man-made) caffeine, which is added to some medicines, foods and drinks. For example, some pain relievers, cold medicines and over-the-counter medicines for alertness contain synthetic caffeine. So do energy drinks and “energy-boosting” gums and snacks.
Unlike many other psychoactive substances, it is legal and unregulated in nearly all parts of the world.
The amount of caffeine varies in drinks, but as a rule:
- An 8-ounce cup of coffee: 95-200 mg
- A 12-ounce can of cola: 35-45 mg
- An 8-ounce energy drink: 70-100 mg
- An 8-ounce cup of tea: 14-60 mg
Reading labels is the best way to track your caffeine intake.
How does it affect the body?
Caffeine acts as a stimulant by exerting an effect on the central nervous system. The effects of caffeine on the body may begin as early as 15 minutes after ingesting and last up to six hours.
Caffeine is recognized as an addictive substance by the World Health Organization (WHO).
When consumed in moderate doses (no more than 200 mg, or about 1-2 6-ounce cups of coffee), caffeine can help people feel more alert and less sleepy. Most individuals consuming moderate amounts will experience few, if any, negative side effects.
Caffeine may increase heart rate, body temperature, blood flow to the skin and extremities, blood pressure, blood sugar levels, stomach acid secretion and production of urine (diuretic). People may experience dizziness, low blood sugar, trouble breathing, muscle tremors, nausea, diarrhea, increased urine, ketones in urine, drowsiness, thirst, anxiety, confusion, irritability, insomnia, changes in appetite, dry mouth, blurred vision and cold sweats.
It may also:
- Increase the release of acid in your stomach, sometimes leading to an upset stomach or heartburn.
- Interfere with the absorption of calcium in the body.
- Increase your blood pressure.
- Create dependency, so you need to take more of it to get the same result.
Contrary to popular belief, drinking coffee will not help someone who is intoxicated become sober.
Sometimes people mix their energy drinks with alcohol. It is dangerous to combine alcohol and caffeine. Caffeine can interfere with your ability to recognize how drunk you are, which can lead you to drink more. This also makes you more likely to make bad decisions.
While consuming moderate amounts of caffeine does not seem to have long-term detrimental effects, consuming larger amounts of caffeine (1,000 mg, or about 10 6-oz cups of coffee a day) on a regular basis may be linked to conception problems, increased episodes of heartburn and changes in bowel habits.
Too much caffeine may lead to sleep deprivation and a tendency to disregard the normal warning signals that the body is tired and needs rest. Caffeine does not replenish energy or prevent emotional fatigue; food and sleep are the only remedies for these. When normal sleeping patterns are continually disrupted, mood depression may occur. Too much caffeine may also lead to anxiety-related feelings such as excessive nervousness, sweating and tremors.
People who take medications for depression, anxiety or insomnia, high blood pressure, other heart problems, chronic stomach upset or kidney disease should limit caffeine until discussing the matter with a clinician.
If you want to avoid some of the annoying side effects of caffeinated beverages (e.g., jitters or sleeplessness), switching to decaffeinated drinks may help.
If you do decide to quit caffeine cold turkey, you may notice some side effects (especially if you are used to consuming large amounts of caffeine)
Some symptoms of caffeine withdrawal include headaches, irritability, nervousness, nausea, constipation and muscular tension. These symptoms usually appear about 12-24 hours after someone has stopped consuming caffeine and usually last about one week. It is recommended that you gradually decrease your caffeine intake to avoid withdrawal symptoms.
If you consume large amounts of caffeine and/or experience some of the symptoms mentioned in this article, it might be time to see if caffeine is affecting your wellbeing and overall health.