Coffee culture carries caffeine risk

Koreans are definitely caffeinated: They love coffee, cola and chocolate as well as foods that contain a large amount of the stimulant.

Though it has been less than two decades since global coffee shop franchises were introduced to the country, industry insiders said about 37 million cups of coffee are sold every day, which means that 24 million economically active people drink more than one cup of coffee a day.

"I love coffee. I started with easy 'coffee mix,' powdered coffee extract with powdered cream and sugar. But now I am addicted to brewed coffee, which smells and tastes better. I drink about 4-5 cups a day," said Kim Seo-yeon, a 32-year-old office worker. "Right after I wake up in the morning, after I have my lunch, during an afternoon break and while I watch TV at night, I always sip coffee."

In addition to the frequent consumption of cola and chocolate, caffeinated energy drinks are gaining popularity among teenagers, who struggle to stay up at night to study.

However, experts warn that excessive caffeine intake could be harmful, especially since they are disguised with flavors, making easy to consume too much.

Caffeine is known for its short-term relief of fatigue or drowsiness since it stimulates the brain and nervous system. It is also known to speed up the dissolution of fat, which may lead to weight loss.

Usually, caffeine leaves the body through the urine system hours after it has been consumed, so there is not much to worry about in regards to intake. But if excessively consumed, it could lead to a fast heart rate, anxiety, depression, difficulty in sleeping, nausea, restlessness, tremors, frequent urinating or vomiting. It even has some reported withdrawal symptoms of drowsiness, headaches, irritability, nausea and vomiting.

"About 400 milligrams of caffeine is tolerable for adults, 300mg for pregnant women, or 2.5 milligrams per kilogram of weight," said Dr. Seo Jeong-wan of Ewha Womans University Medical Center. "It is equivalent to three-four cups of brewed coffee. But it could easily be filled by drinking 250 milliliters of cola, one canned coffee and 1 gram of chocolate, too. Therefore, people should watch what they are eating."

Seo said teenagers should be extra alert about caffeine intake since they are in a critical stage of bone formation.

"If you drink caffeinated drinks instead of dairy, the facilitation of urination will take away the essential calcium and curb the growth of bone. If you are an adult, osteoporosis could be forecasted, too," he added.

He advised teenagers to not rely on caffeine to overcome drowsiness.

"It could lead to insomnia if you take it for too long. Open the window, do stretching and eat food that are abundant in vitamin C such as citrons and other fresh fruits," he said.