Students Consume More Caffeine Than Researchers Had Thought

Because they get nearly half of their daily caffeine intake from soft drinks, college students may be at greater risk of heart disease than previous studies have indicated, according to the results of a recent study at the State University of New York (SUNY) at Stony Brook.

Caffeine consumption is typically measured only by the amount of tea or coffee consumed. Therefore, the amount of caffeine ingested by college-aged adults may have been underestimated in previous studies, the study said.

Because previous studies have linked large caffeine intakes with heart disease, the risk of heart disease may also have been underestimated among people of this age group.

The risk of heart disease to older adults, who have been found to consume most of their caffeine in coffee or tea, has likely been measured more accurately. Older adults get only 6 percent fo their caffeine from soft drinks, according to Drs. Gerdi Weidner and Joseph Istvan, who reported their findings in the November 28 New England Journal of Medicine.

"Students should become a lot more aware of the caffeine [in soft drinks], and should request that the amount of caffeine be printed on the cans," said Weidner.

Brewed coffee contains almost twice as much caffeine--approximately 120 mg per six-ounce cup--as does instant coffee, which has only 66 mg.

Of the soft drinks, which unlike tea and coffee are caffeinated artificially, Mountain Dew contains the most, with 55 mg per 12-ounce can. Both Coke and Diet Coke contain approximately 46 mg of caffeine, while Pepsi has about 38 mg, Weidner said.

By comparison, the over-the-counter stimulant No-Doz lists its caffeine content as 100 mg per pill.

Even many pain relievers contain caffeine. Anacin, for example, has 32 mg of caffeine in each tablet to counterbalance the drowsiness effect of pure aspirin, Weidner said.

Both Weidner and University Health Services Director Dr. Warren E. C. Wacker said that the amount of caffeine consumed in two to three cups of coffee a day was relatively safe. However Weidner cautioned that anything above that "would be harmful," and that smokers, who are already at risk of heart disease, should be "especially careful."

Caffeine requires about 30-40 minutes to work, the stimulatory effect lasting one to two hours, depending on the person, Weidner said.

The long-term effects of caffeine are unclear, she said, but added that in addition to heart disease, large doses of caffeine have been associated with cancer and pregnancy difficulties.