Caffeine

Caffeine is one of the most comprehensively studied ingredients in the food supply. We know a lot about caffeine and it has been consumed safely for centuries. Caffeine exists in our diet from a variety of sources primarily coffee, tea, chocolate, cola drinks, and both prescription and nonprescription drugs. While much is known about caffeine, many questions and misperceptions still exist; these facts and resources can help to set the story straight.

What are the effects of caffeine?

Caffeine is a mild stimulant to the central nervous system, so it can temporarily increase your alertness when ingested in moderate amounts. However, some people are more sensitive to caffeine’s effects due to genetics, age, or body size. For example, a child or a smaller person may feel caffeine’s effects more strongly than an adult or a heavier person. When a person regularly ingests caffeine, abruptly stopping caffeine intake may cause headaches, fatigue or drowsiness. A cup of strongly brewed coffee or tea has more caffeine than a weakly brewed cup.

How much caffeine is "safe?"

Moderation is the key. Most experts agree that 300 mg of caffeine (about the amount contained in 3 cups of coffee) is a moderate intake. People who have certain health problems need to check with their doctor as they consider their caffeine intake. At this time, there is no conclusive evidence that caffeine intake is associated with heart disease, hypertension, osteoporosis or high cholesterol. Because research is ongoing, ask your doctor for guidance about your consumption. Some people are more sensitive to caffeine's effects than others and may feel effects at smaller doses. Pregnancy and aging may affect one's sensitivity to caffeine. There is no conclusive evidence that caffeine in beverage form is dehydrating. Its diuretic effects are usually compensated for by the beverage's fluid content. If you ingest caffeine from sports supplements, prescription drugs, or over-the-counter sources, be sure to drink adequate fluid to re-hydrate yourself from caffeine's mild diuretic action.

Will caffeine help me study?

Caffeine may help you stay awake and be alert to study, but it will not improve your performance on an exam the next day if you have not gotten enough rest or are exhausted from an all-nighter.

How can I energize?

Instead of reaching for another soda or coffee, try these non-caffeinated strategies to maintain good energy levels:

Can I safely have caffeine if I am pregnant or if I am considering pregnancy?

At this time, moderate caffeine intake is not believed to affect either fertility or the health of a mother or fetus. Until more is understood about the link between caffeine and pregnancy outcomes, try to avoid high caffeine consumption. Try to limit coffee to three cups per day or less. Caffeine is passed into breast milk and little data exists about the effects on infants. Therefore, try to avoid caffeine while breastfeeding.

I get my caffeine from coffee and/or herbal supplements – and I would like to lose weight. Is it safe to take an herbal supplement to help me lose weight or to stay awake?

Currently, there is mixed evidence for caffeine’s role in weight loss. However, caffeine is often included in herbal supplements for weight loss, especially in high doses. These supplements often contain other nervous system stimulants such as guarana or ephedra (ma huang). Weight loss supplements containing ephedra have been associated with illness and death. For additional information, visit the U.S. Food and Drug Administration website (http://www.fda.gov/) and search for "dietary supplements."

Taking diet supplements containing these ingredients and maintaining your usual caffeine intake can push you past the recommended moderate level of caffeine intake. Remember the "moderate" caffeine limit is 300 mg/day - and realize that herbal stimulants may be dangerous, as they are not regulated by the FDA. They may contain much more or much less than what it says on the package.

How can I quit or reduce my caffeine consumption?

The amount of caffeine in some common foods and beverages is as follows:

Some common brands of medication that contain caffeine are:

Resources:

References:

"Wake Up!" A Dietitian's View: Nutrition and Fitness Information for the Misinformed (Blog posting 11 Feb 2005) http://www.roadtonutrition.com/archives/000122.html
Johns Hopkins University School of Medicine, Bayview Campus, Behavioral Biology Research Center. "Information about Caffeine Dependence." [Adapted from Griffiths, R.R., Juliano, L.M., & Chausmer, A.L. (2003). Caffeine pharmacology and clinical effects. In: Graham A.W., Schultz T.K., Mayo-Smith M.F., Ries R.K. & Wilford, B.B. (eds.) Principles of Addiction Medicine, Third Edition (pp. 193-224). Chevy Chase, MD: American Society of Addiction] 9 July 2003. http://www.caffeinedependence.org/caffeine_dependence.html 12 May 2010.