Such adverse’ reactions are rare among healthy adults when coffee or tea is drunk moderately, that is, in quantities of about 200 to 250 milligrams daily (about two. cups of brewed coffee). The effects of caffeine tend to be more severe among people who don’t ingest it regularly; regular consumers seem, to take caffeine’s effects in stride. Children run a risk of their own version of coffee nerves, since one cola for a small child may have the same effect as four cups of coffee for an adult. The authors of one ” study found behavioral changes in children who drank the equivalent of six cans of cola, not an unusual amount on a warm day, which adds up to more than 270 milligrams of caffeine. But the same researchers later found that children who regularly consume caffeine are less affected than children who do not. They conclude that

Hyperactive children might selectively ingest caffeine”; it remains to be proven that caffeine causes hyperactivity.

Many, perhaps all, such discrepancies in studies of the effects of differing amounts of caffeine can be explained, according to Dr. David Robertson of Vanderbilt University Medical Center in Nashville, by the fact that researchers have not consistently distinguished between habitual coffee consumers and the occasional laboratory volunteer who ingests large doses of caffeine over the course of ‘an experiment. A dose of 250 milligrams given to a regular coffee drinker has no significant effect on blood pressure, heart rate, respiration, metabolic rate, blood glucose concentration, or cholesterol level. But caffeine administered to subjects who haven’t been consuming caffeine for a week or two can raise all these rates and levels.

Article extracted from this publication >> July 22, 1988