How much is too much caffeine?

A recent study by the Swiss National Science Foundation reported caffeine consumption can slow brain development in teenagers.

During the study, researchers at the University Children’s Hospital in Zurich found caffeine equaling three to four cups of coffee per day for humans reduced deep sleep and delayed the maturation of the brains in prepubescent mice. Researchers are finding parallels between what happened in the mice and what could happen in teenagers.

Mike Elliott, secondary director of the Washington County Career Center, said he and Superintendent Dennis Blatt monitor the students as they come into the building each morning.

“Less than 5 percent of our students drink coffee,” Elliott said. “I don’t see a lot of coffee drinks or energy drinks. Far and away, soda and tea are most prevalent.”

According to the Food and Drug Administration, most adults can drink about 400 milligrams of caffeine per day, equivalent to four to five cups of coffee. However, no safe level of caffeine consumption has been developed.

The Canadian government, however, has some guidelines, said Dr. Nicole Caldwell, assistant professor of pediatrics Nationwide Children’s Hospital in Columbus. For children aged 4 to 6 years, the maximum recommended intake is 45 milligrams a day – about as much caffeine as found in a 12-ounce Diet Coke.

“Caffeine affects the central nervous system as a stimulant,” Caldwell said. “The brains of a child tend to be a little bit more sensitive to caffeine’s effects than the brains of adults. Caffeine can cause them to be hyperactive, which is obvious. But it also can make them nervous, anxious, worsen stomach problems and create sleep problems.”

Cody Shankland, 17, of Marietta, and a senior at the career center and Marietta High School, said he typically drinks up to eight cans of soda per day, either Mountain Dew or Coke, although he knows it’s not a good practice.

“It’s pretty unhealthy and causes a lot of damage,” Shankland said. “People should drink more water. It’s kind of addicting because there’s a stronger kick to it and just more of a flavor (than water).”

Shankland said his mother says he drinks too many of the soft drinks.

Caffeine increases heart rate and blood pressure. Not only could it have an effect on a child’s neurological development, as suggested by the Swiss study, but it also could affect the cardiovascular system, according to the American Academy of Pediatrics.

By the same token, tea can be highly caffeinated. The Mayo Clinic in Rochester, Minn., reported a Lipton Brisk lemon iced tea contains 5 to 7 milligrams of caffeine. A generic unsweetened tea can contain 26 mg in 8 ounces. The highest caffeine content is black tea which contains from 14 to 61 mg in 8 ounces.

Dakota Tidd, 18, a senior at the career center and Fort Frye High School, drinks at least three large McDonald’s sweet teas per day.

“Caffeine has its effects on people in different ways,” Tidd said. “Some people, it has to do with your weight. Some people, it has to do with your brain. I don’t notice it. I just drink it.”

Tidd, like Shankland, has family members trying to get him to drink less sweet tea.

“My grandmother actually talks about that I should drink more water,” Tidd said. ” I agree with her.”