Aug 16 - 22, 20

Caffeine is a psychoactive stimulant drug found naturally in coffee beans, tea leaves, cocoa beans (chocolate) and kola nuts (cola) and added to soft drinks, foods, and medicines like pain relievers and other over-the-counter medications.

Caffeine is defined as a drug because it stimulates the central nervous system, causing increased alertness. Caffeine gives most people a temporary energy boost and elevates mood.

The word "caffeine" came from the German Kaffee and the French cafe meaning, of course, coffee. In its natural form, caffeine tastes very bitter. But most caffeinated drinks have gone through enough processing to camouflage the bitter taste.

Caffeine is an alkaloid. This is metabolised in the liver and the breakdown products of caffeine are excreted through the kidney.

- A cup of coffee has 100-250 milligrams of caffeine.

- Black tea brewed for four minutes has 40-100 milligrams.

- Green tea has one-third as much caffeine as black tea.

In doses of 100-200 mg caffeine can increase alertness, relieve drowsiness, and improve thinking. At doses of 250-700 mg/day, caffeine can cause anxiety, insomnia, nervousness, hypertension, and insomnia. Caffeine is a diuretic and increases urination. It can curiously enough make it more difficult to lose weight because it stimulates insulin secretion, which reduces serum glucose, which increases hunger.

Caffeine is not stored in the body, but you may feel its effects for up to six hours. In pregnancy, it is 18 hours. In women on oral contraceptives, the rate at which they clear caffeine from the body is considerably slower.

Caffeine can help relieve some headaches, so a number of over-the-counter and prescription pain relievers include it as an ingredient, usually with aspirin or another analgesic.

In humans, caffeine is a central nervous system (CNS) stimulant, having the effect of temporarily warding off drowsiness and restoring alertness. Beverages containing caffeine such as coffee, tea, soft drinks, and energy drinks enjoy great popularity.


Common sources of caffeine are coffee, tea, and to a lesser extent chocolate derived from cocoa beans. Less commonly used sources of caffeine include the yerba mat and guarana plants, which are sometimes used in the preparation of teas and energy drinks. Two of caffeine's alternative names, mateine and guaranine are derived from the names of these plants.

One of the world's primary sources of caffeine is the "coffee bean" (which is the seed of the coffee plant), from which coffee is brewed. Caffeine content in coffee varies widely depending on the type of coffee bean and the method of preparation used. In general, one serving of coffee ranges from 40 milligrams, for a single shot (30 milliliters) of arabica-variety espresso, to about 100 milligrams for a cup (120 milliliters) of drip coffee. In general, dark-roast coffee has less caffeine than lighter roasts because the roasting process reduces the bean's caffeine content. Arabica coffee normally contains less caffeine than the robusta variety. Coffee also contains trace amounts of theophylline, but no theobromine.

Tea is another common source of caffeine. Although tea contains more caffeine than coffee (by dry weight), a typical serving contains much less, as tea is normally brewed much weaker. Besides strength of the brew, growing conditions, processing techniques- and other variables also affect caffeine content. Certain types of tea may contain somewhat more caffeine than other teas. Black tea brewed for four minutes has 40-100 milligrams. Green tea has one-third as much caffeine as black tea. Teas like the pale Japanese green tea gyokuro contain far more caffeine than much darker teas like lapsang souchong, which has very little.

Caffeine is also a common ingredient of soft drinks such as cola, originally prepared from kola nuts. Soft drinks typically contain about 10 to 50 milligrams of caffeine per serving. By contrast, energy drinks such as Red Bull can start at 80 milligrams of caffeine per serving. The caffeine in these drinks either originates from the ingredients used or is an additive derived from the product of decaffeination or from chemical synthesis. Guarana, a prime ingredient of energy drinks, contains large amounts of caffeine.

Chocolate derived from cocoa beans contains a small amount of caffeine. The weak stimulant effect of chocolate may be due to a combination of theobromine and theophylline as well as caffeine. A typical 28-gram serving of a milk chocolate bar has about as much caffeine as a cup of decaffeinated coffee, although some dark chocolate currently in production contains as much as 160 mg per 100g.

In recent years, various manufacturers have begun putting caffeine into shower products such as shampoo and soap. Studies show that caffeine in shampoo applied for two minutes is absorbed through the skin, mostly through hair follicles, and reaches the blood stream.

Caffeine is also used pharmacologically to treat apnea in premature newborns and as such is one of the 10 drugs most commonly given in neonatal intensive care. Various manufacturers market caffeine tablets claiming that using caffeine of pharmaceutical quality improves mental alertness. These effects have been borne out by research that shows that caffeine use (whether in tablet form or not) results in decreased fatigue and increased attentiveness.

After all, one cannot have too much caffeine without feeling its side effects at least two hours after the intake. It is common knowledge that drinking too much coffee can lead to experiencing the jitters, as well as insomnia. But these two are not the only side effects that you can encounter when having too much caffeine in your system.


Caffeine is good because it gives you a popping burst of energy and can keep you on your toes - at least for a couple of hours. That is because caffeine blocks adenosine, which is a chemical in the body that tells it to shut down when tired.

Some of the negative side effects that caffeine has, which you may not be aware of, are:

1. Panic attacks. Caffeine keeps us up because it triggers the fight-or-flight mechanism in our bodies. But after heavy doses of caffeine and after many hours of it being in our system, the fight-or-flight instinct gets reduced to panic attacks. Your hands become shaky, your skin sweaty, and you always expect bad things to happen to you.

2. Addiction. Caffeine is addictive. Once we get into the habit of getting our caffeine fix, our body begins to crave the boost that we get from it. If we fail to get the dose of caffeine that our body has adapted to, we become irritable, tired, and even depressed.

3. Dehydration. One would think that since coffee is liquid, it can hydrate you. Actually, the caffeine in coffee and any other foodstuffs that has it is linked with dehydration. That is mainly because of caffeine's diuretic properties.

4. PMS. Women who drink a lot of coffee and eat a lot of chocolates tend to experience pre-menstrual syndrome more acutely than women who do not. The headaches, the bloated feeling and the belly cramps become keener with the added consumption of caffeine.

5. Emotional fatigue. Caffeine wakes up the body, but what it fails to do is to tell the body when to stop moving and simply rest. The body needs rest and when the body does not get it, it can lead not just to physical tiredness but also emotional fatigue.


So far we have talked about the bad side effects that you can get from caffeine. But caffeine is not that bad at all. We can also gain some good side effects from caffeine, too.

1. Alertness. Caffeine keeps our minds alert, even for just an hour or two. Regular consumption of caffeine can keep our minds more active and increase our brain power.

2. Parkinson's disease. Studies have shown that it is highly possible for caffeine to prevent the occurrence of Parkinson's disease. The purported reason is that caffeine keeps the dopamine in the system active. Dopamine is the chemical that activates the pleasure centers in the brain.

3. Heart disease. Caffeine is said to prevent heart disease - as long as you do not already have it in the first place. That is because caffeine is an antioxidant, and antioxidants prevent heart ailments and some forms of cancer.

4. Diabetes. Caffeine triggers the production of adrenaline and cortisol - two substances associated with the body's fight-or-flight response. When these chemicals are released into the system, they cause the liver to burn up more sugar. However, this works only with the caffeinated foodstuffs that are not sweetened.

5. Stamina. Again, this has something to do with the fight-or-flight response. Consuming caffeine before workout or doing any athletic activity slows down the adenosine that causes muscle fatigue. This makes you move faster and endure more.

Caffeine is good for the body, but it is also bad if the intake is too much. Too much is defined as more than 300mg of caffeine every day. In order to measure and monitor the amount of caffeine you are taking in daily and to reduce the negative side effects of caffeine, do some caffeine testing with your food.


The precise amount of caffeine necessary to produce effects varies from person to person depending on body size and degree of tolerance to caffeine. It takes less than an hour for caffeine to begin affecting the body and a mild dose wears off in three to four hours. Consumption of caffeine does not eliminate the need for sleep. It only temporarily reduces the sensation of being tired throughout the day. In general, 25 to 50 milligrams of caffeine is sufficient for most people to report increased alertness and arousal as well as subjectively lower levels of fatigue.

Caffeine citrate has proven to be of short- and long-term benefit in treating the breathing disorders of apnea of pre-maturity and bronchopulmonary dysplasia in premature infants. The only short-term risk associated with caffeine citrate treatment is a temporary reduction in weight gain during the therapy, and longer term studies (18 to 21 months) have shown lasting benefits of treatment of premature infants with caffeine. Caffeine relaxes the internal anal sphincter muscles and thus should be avoided by those with fecal incontinence.

Caffeine also increases the effectiveness of some drugs. Caffeine makes pain relievers 40 per cent more effective in relieving headaches and helps the body absorb headache medications more quickly, bringing faster relief. For this reason, many over-the-counter headache drugs include caffeine in their formula. It is also used with ergotamine in the treatment of migraine and cluster headaches as well as to overcome the drowsiness caused by antihistamines.


Two infrequently diagnosed caffeine-induced disorders that are recognised by the American Psychological Association (APA) are caffeine-induced sleep disorder and caffeine-induced anxiety disorder, which can result from long-term excessive caffeine intake.

In the case of caffeine-induced sleep disorder, an individual regularly ingests high doses of caffeine sufficient to induce a significant disturbance in his or her sleep, sufficiently severe to warrant clinical attention.

In some individuals, large amounts of caffeine can induce anxiety severe enough to necessitate clinical attention. This caffeine-induced anxiety disorder can take many forms, from generalised anxiety to panic attacks, obsessive-compulsive symptoms, or even phobic symptoms.


An array of studies found that caffeine could bring certain changes in memory and learning. Researchers have found that long-term consumption of low dose caffeine slowed hippocampus-dependent learning and impaired long-term memory in mice. In another study, caffeine was added to rat neurons in vitro. The dendritic spines (a part of the brain cell used in forming connections between neurons) taken from the hippocampus (a part of the brain associated with memory) grew by 33 percent and new spines formed. After an hour or two, however, these cells returned to their original shape.

Another study showed that human subjects - after receiving 100 milligrams of caffeine - had increased activity in brain regions located in the frontal lobe, where a part of the working memory network is located, and the anterior cingulate cortex, a part of the brain that controls attention. The caffeinated subjects also perform better on the memory tasks. In essence, caffeine consumption increases mental performance related to focused thought while it may decrease broad-range thinking abilities.


According to one study, caffeine in the form of coffee significantly reduces the risk of heart disease in epidemiological studies. However, the protective effect was found only in participants who were not severely hypertensive (i.e., patients that are not suffering from a very high blood pressure). Furthermore, no significant protective effect was found in participants aged less than 65 years or in cerebrovascular disease mortality for those aged equal or more than 65 years. Research suggests that drinking caffeinated coffee can cause a temporary increase in the stiffening of arterial walls. Caffeine binds to receptors on the surface of heart muscle cells, which increases the amount of ATP available for muscle contraction and relaxation.


It is a common myth that excessive intake of caffeine results in stunted growth within children, particularly younger children and teenagers...recently, scientific studies have disproved the notion. Children are found to experience the same effects from caffeine as adults.

However, subsidiary beverages that contain caffeine such as energy drinks, most of which contain high amounts of caffeine, have been banned in many schools throughout the world due to other adverse effects having been observed. In one study, caffeinated cola has been linked to hyperactivity in children.

Caffeine Intake During Pregnancy (Some Conceptions and Misconceptions):

A 2008 study suggested that pregnant women who consume 200 milligrams or more of caffeine per day have about twice the miscarriage risk as women who consume none. However, another 2008 study found no correlation between miscarriage and caffeine consumption. The UK Food Standards Agency has recommended that pregnant women should limit their caffeine intake to less than 200 mg of caffeine a day...the equivalent of two cups of instant coffee or a half to two cups of fresh coffee. Dr De-Kun Li of Kaiser Permanente Division of Research, writing in the American Journal of Obstetrics and Gynecology, concluded that an intake of 200 milligrams or more per day, representing two or more cups, "significantly increases the risk of miscarriage". However, Dr. David A. Savitz, a professor in community and preventive medicine at New York's Mount Sinai School of Medicine and lead author of the other new study on the subject published in the January issue of Epidemiology, found no link between miscarriage and caffeine consumption.