By Bae Ji-sook
Staff Reporter

How much coffee, cola or tea do you drink a day? Do you enjoy a bite of a chocolate bar? If you do, then you should learn about caffeine.

According to encyclopedias, caffeine is a xanthine alkaloid compound that acts as a psychoactive stimulant in humans. It is found in beans, leaves, and the fruit of over 60 plants, where it acts as a natural pesticide that paralyzes and kills certain insects feeding on the plants.

It is most commonly consumed by humans in infusions extracted from the beans of the coffee plant and the leaves of the tea bush, as well as from various foods and drinks containing products derived from the kola nut or cacao.

Weekly Hankyoreh 21 said Koreans are one of the largest consumers of instant coffee mix. It assumed that a Korean adult has at least two bags of instant coffee, sugar and cream mixture at home or at work.

It's not only coffee. In 1999, Koreans drank sixty-two 237-milliliter cups of cola a year. Green tea, which is also one of the best selling beverages in the nation, contains a certain amount of caffeine.

Caffeine has an awakening effect on human bodies. It has the effect of warding off drowsiness and restoring alertness.

It also has diuretic effect as it stimulates digestion. Those who have a stomachache from eating too much or have gas, drinking beverages containing caffeine might remedy it. Moreover, some people say caffeine is effective for quiting drinking. Drinking a cup of coffee gets rid of urge to drink alcohol, they say.

However, caffeine has its side effects. Doctors advise pregnant women to not drink coffee or lessen its amount, because caffeine can get into cell tissue and affect the placenta or even fetus. One or two cups a day may be fine but more may be bad, they say.

Also, its awakening effect induces insomnia in some people. Some people are very sensitive to caffeine and drinking a cup of coffee may lead to a sleepless night. Some doctors advise their patients to refrain from drinking coffee in the evening or at night.

It is related to ulcers, too. Those who feel like vomiting or bilious should refrain from having it.

Caffeine is, most of all, said to be addictive. Those who are used to having a certain amount per day cannot get do without it, people say.

The Food and Drug Administration recently announced recommendations for caffeine intake. It said less than 400 milligrams and 300 milligrams per day is recommendable to adults and pregnant women, respectively. It also advised children to have less than 2.5 milligrams of caffeine per 1 kilogram of their weight.

According to the government, there are an average of 69 milligrams of caffeine in one 12-gram coffee mix bag, 23 milligrams for 250-milliliter cola, 16 milligrams per 30 grams of chocolate.

The recommendation means a six-year-old child weighing 23 kilograms should not drink more than a can of cola, a piece of chocolate and one coffee flavor ice cream. A high school student should not eat more than two cans of canned coffee.

``People are not very aware of food they eat and the caffeine in it,'' a food and drug administration spokesperson said, adding parents should watch their children's caffeine intake.

bjs@koreatimes.co.kr