There are several forms of caffeine and it can come from coffee, tea, cola, chocolate, energy drinks etc. Caffeine is a central nervous system stimulant, having the effect of warding off drowsiness and restoring alertness. Beverages containing caffeine enjoy popularity great enough to make caffeine the world's most popular psychoactive drug. Coffee comes in at 54% of total caffeine consumed and tea at 43% with the remainder coming mostly from chocolate products.
Different sources of caffeine
Caffeine is an alkaloid found in numerous plant varieties. The most commonly used are coffee and tea.
Coffee bean
Everyone probably knows that the world's primary source of caffeine is the coffee bean, from which coffee is brewed. Although it depends on the variety of coffee bean and the method of preparation used, in general one serving of coffee ranges from about 40 mg for a single shot of Arabica variety espresso to about 100 mg for strong drip coffee. Coffee also contains trace amounts of Theophylline, but no Theobromine.
Tea leaves
Tea leaves is also another common source of caffeine in many cultures. Tea generally contains somewhat less caffeine per serving than coffee, depending on the strength of the brew. Tea contains small amounts of Theobromine and slightly higher levels of Theophylline than coffee.
Kola nuts
Caffeine is also a common ingredient of soft drinks such as cola. Soft drinks typically contain about 10 mg to 50 mg of caffeine per serving. The caffeine in high energy drinks either originates from the ingredients used or is an additive derived from the product of decaffeination or from chemical synthesis.
Cocoa
Chocolate derived from cocoa also contains some amounts of caffeine but it is a weak stimulant, mostly due to its content of Theobromine and Theophylline.
However, chocolate contains too little of these compounds in a reasonable serving to create effects in humans that are on par with coffee.
Common caffeine effects
Caffeine can boost energy temporarily, and makes a person feel more awake and ready for the day.
Caffeine:
- is a central nervous system stimulant
- is metabolic stimulant
- can reduce physical fatigue
- restores mental alertness when unusual weakness or drowsiness occurs
- increases alertness and wakefulness
- causes faster and clearer flow of thought
- increases focus
- can boost general body coordination
- causes restlessness,
- causes a loss of fine motor control
It is important to remember that consumption of caffeine does not eliminate a need for sleep.
Caffeine as a medication
Caffeine is sometimes used in combination with medicines to increase their effectiveness. Some of those medications are ergotamine in the treatment of migraine and cluster headaches, or with certain pain relievers such as Aspirin or acetaminophen.
Not only that, but for several years now it has also been used to overcome the drowsiness caused by antihistamines. Breathing problems in premature infants are sometimes treated with caffeine, which is available only by prescription in many countries.
Caffeine and addiction
Coffee has been heavily criticized for the fact that its caffeine content is addictive and unhealthy. However, most experts now believe that if you drink coffee with moderation, it can actually be beneficial. Coffee drinkers do not require increasing amounts of caffeine over prolonged periods of time (characteristics of addictive substances) and they can moderate or change their consumption with no difficulty. The caffeine contained in coffee will give you a significant boost of energy, provide you with an increase in performance for more tasks and also help you stay awake during drawn out tasks such as long distance driving. Other group of experts are saying that caffeine is definitely addictive because there are some serious withdrawal symptoms.
Possible side effects of caffeine
Lethal dose
The minimum lethal dose of caffeine ever reported is 3,200 mg, administered intravenously. Although achieving lethal dose with coffee would be exceptionally difficult, there have been many reported deaths from intentional overdosing on caffeine pills.
Physical and mental disorders
There are 4 caffeine-induced psychiatric disorders and they include:
- caffeine intoxication
- caffeine-induced anxiety disorder
- caffeine-induced sleep disorder
- caffeine-related disorder not otherwise specified
Symptoms of caffeine intoxication include:
- restlessness
- nervousness
- excitement
- insomnia
- flushed face
- diuresis
- muscle twitching
- rambling flow of thought and speech
- paranoia
- cardiac arrhythmia or tachycardia
- psychomotor agitation
- gastrointestinal complaints
- increased blood pressure
- rapid pulse
- vasoconstriction
- increased amounts of fatty acids in the blood
- increased production of gastric acid
In extreme cases:
- mania
- depression
- lapses in judgment
- disorientation
- loss of social inhibition
- delusions
- hallucinations
- psychosis
Because caffeine increases the production of stomach acid, high usage over time can lead to peptic ulcers, erosive esophagitis, and gastro-esophageal reflux disease.
Caffeine withdrawal symptoms
The most important proof that caffeine is addictive is presence of caffeine withdrawal symptoms. It is proven that regular caffeine consumption reduces sensitivity to caffeine. When caffeine intake is reduced, the body becomes oversensitive to adenosine which leads to sensitiveness, blood pressure drop, excess of blood in the head and headache.
This headache, well known among coffee drinkers, usually lasts from one to five days, and can be alleviated with analgesics such as Aspirin.
Often, people who are reducing caffeine intake report:
- being irritable
- unable to work
- nervous
- restless
- feeling sleepy
- having a headache
- nausea and vomiting in extreme cases
- drowsiness
- feeling hot and cold
- apathy
- inability to concentrate
- constipation
- runny nose
Caffeine and pregnancy
Several researches tried to prove that caffeine is causing some mal-formations in fetus, and that it may reduce fertility rates. It is known that caffeine does causes malformations in rats, when ingested at rates comparable to 70 cups a day for humans. Many other species respond equally to such large amounts of caffeine. It is also important to know that one recent study found a weak link between Sudden-Infant-Death-Syndrome (SIDS) and caffeine consumption by the mother, which reinforces the recommendation for moderation or even abstinence.
Avoiding the jitters
Almost everyone has experienced jitters - the nasty side effects from drinking caffeine which would really interfere with some normal everyday activities. The way to avoid the jitters and severe withdrawal symptoms is to keep caffeine intake fairly steady. If you are looking to lower your caffeine intake from coffee, do it gradually over a course of a week or two.
Most experts suggest that, if you haven't started drinking coffee yet, you should try it once in a while when you start feeling tired and enjoy its great taste. If the taste is what keeps you away from the hot drink, try one of those cool mocha lattes.
Heart health, cancer and caffeine
Several studies done earlier have came to the possible link between caffeine consumption and heart disease as well as certain cancers, especially breast cancer. However some recent studies have shown no support for these links what so ever. While it is proven that high consumption of coffee may cause a slight increase in blood cholesterol, there is no indication of direct harm.
Weight loss and caffeine
It seems that caffeine increases the caloric burning rate. This caloric burn rate is even greater with exercise. The caffeine seems to make body fat more readily available as fuel to exercising muscles.
Item
Serving
Caffeine
Size (oz)
Content (mg)
Brewed Coffee
8
60-90
Instant Coffee
8
75-125
Drip Coffee
8
95-150
Espresso
Single
100
Cappuccino
Single
100
Decaf
8
8
Strong tea
8
60-75
Weak tea
8
40-50
Cola
12
30-56
Diet Cola
12
38-65
Sprite/7Up
12
0
Chocolate
2
10-50
Cocoa
5
4
Diet Pills
1
100-200
No-Doz
1
100
Vivarin
1
200
Pain Relievers
1
30+
- en.wikipedia.org/wiki/Caffeine
- www.myfit.ca
- www.askmen.com
- image: www.headache-adviser.com
- Photo courtesy of Zhao ! by Flickr : www.flickr.com/photos/kodomut/4608651380/