The Levels Consumed by Most People Generally have Positive Effects

Depending on the amount of caffeine consumed, it can have a mild central nervous stimulating activity. However, caffeine does not accumulate in the body and is metabolized and excreted within a few hours of consumption. Mean caffeine intake, in adults, in the U.S., is about 4 mg/kg. This is about 200-300 mg per person or about 2-3 cups of coffee a day. In the U.S. the caffeine intake for adults over 25 is mostly from coffee. The amount of caffeine in various beverages may be found at the web site www.ameribev.org. An 8 oz cup of coffee typically contains 104-192 mg of caffeine, 8 oz of tea 20-90 mg, and an 8 oz soft drink 20-40 mg. By FDA regulation, soft drinks do not contain more than 6 mg/ounce of caffeine.

A recent review on the effects of caffeine on human health (Food Additives and Contaminants v.20, 1-30, 2003) reported that for the healthy adult population, moderate daily caffeine consumption at levels up to 400-450 mg per day was not associated with adverse effects including cardiovascular effects, behavioral changes, increased incidence of cancer, effects on bone status, effects on male fertility or general toxicity. The report also recommended women contemplating pregnancy to consume a maximum amount of 300 mg/day and children 4-6 years of age to 45 mg/day.

It has been reported that doses of caffeine similar to those consumed by the majority of the population increases alertness and the ability to sustain attention. Caffeine consumption also reduces fatigue and this may be especially important in low arousal situations. In contrast to the effects of caffeine consumption, withdrawal of caffeine has few effects on performance. Scientific studies confirm that although many people enjoy caffeinated products, those who choose to stop consuming or reduce caffeine in their diets can do with without difficulty. The side effects that some people experience, such as headaches, tend to be mild and pass within a few days.

Thus the safety of moderate consumption of caffeine has been affirmed by hundreds of peer reviewed scientific studies, regulatory agencies and scientific organizations and human consumption for hundreds of years.