Caffeinated Concerns Neil H. Mermelstein | May 2015, Volume 69, No.5


Coffee and teaCaffeine (1,3,7-trimethylxanthine) has been consumed in coffee, tea, and chocolate for hundreds of years and in soft drinks for more than 120 years. It is also consumed as an additive in energy drinks and dietary supplements. It occurs naturally in more than 60 plants, including coffee beans, tea leaves, kola nuts, and cocoa pods; it is also synthetically manufactured. The caffeine content of foods and beverages varies with the type of product and the method in which it is prepared. The major food sources of caffeine are coffee, soft drinks, and tea. An eight ounce serving of regular brewed coffee contains 75.2 mg –164.8 mg of caffeine, regular brewed tea contains 15.2 mg – 47.2 mg, cola soft drinks have 24.0 mg – 46.4 mg, other carbonated soft drinks have 17.2 mg– 55.2 mg, and energy drinks contain 27.2–164.0 mg. Caffeine is rapidly absorbed from the gastrointestinal tract and metabolized in the liver. Among its beneficial effects are enhancement of mental alertness, concentration, and physical endurance and reduction of fatigue. It has also been linked to weight loss. Studies have shown that moderate consumption of naturally occurring caffeine, such as in coffee and tea, by healthy adults is not associated with adverse health effects, but concerns have been raised about the effects on other populations such as children and people with health problems. As a result, the safety of caffeine and caffeine-containing foods and beverages has been the subject of numerous reviews, conferences, publications, and regulatory actions over the years.

U.S. Food and Drug Administration
The U.S. Food and Drug Administration (FDA) cites the view of HealthCanada that daily consumption of 400 mg of caffeine—about four or five cups of coffee—is safe for healthy adults. The FDA has not defined moderate and excessive intake levels for children and adolescents. The use of caffeine in cola-type beverages at up to 200 parts per million is generally recognized as safe (GRAS), but there have been concerns about the effect of caffeine consumption at higher levels, caffeine consumption by children and pregnant women, and possible over-consumption because of a wide variety of products containing added caffeine. Attention has also been focused on energy drinks and beverages that contain caffeine and other stimulants that are usually marketed to improve energy, stamina, athletic performance, or concentration. The FDA has warned or taken action against several types of products containing added caffeine, including the following.

Caffeinated alcoholic beverages. The FDA and its sister agency, the Centers for Disease Control and Prevention, have warned about the dangers of mixing alcohol and energy drinks, saying that the high amounts of caffeine in energy drinks can mask the intoxicating effects of alcohol while having no effect on the metabolism of alcohol by the liver, thus increasing the risk of alcohol-related harm and injury. On November 12, 2009, the FDA notified nearly 30 manufacturers of certain alcoholic beverages containing added caffeine that it intended to look into the safety and legality of their products and asked them to provide their rationale and data for concluding that its use of caffeine in an alcoholic beverage is GRAS or prior sanctioned. On November 17, 2010, the FDA told the manufacturers of premixed alcoholic beverages containing caffeine as an ingredient that the addition of caffeine to alcoholic beverages was not GRAS and that it had not approved the use of caffeine in alcoholic beverages at any level. The companies subsequently stopped manufacturing and marketing those products.

Caffeinated gum. On May 8, 2013, William Wrigley Jr. Co., Chicago, Ill (, announced that it was suspending the production and marketing of Alert Energy Caffeine Gum after discussions with the FDA regarding the agency’s concern about the proliferation of caffeine in the food supply.

Powdered caffeine. On July 18, 2014, the FDA warned about the marketing of powdered pure caffeine directly to consumers, particularly in bulk bags via the Internet, after two deaths occurred from the consumption of powdered caffeine. A single teaspoon of pure caffeine is approximately equal to the amount in 25 cups of coffee.