Health Encyclopedia

Caffeine in the diet

Definition

Caffeine is a substance that exists naturally in certain plants. It can also be produced synthetically and used as an additive in food products. It is a central nervous system stimulant and a diuretic.

Alternative Names

Diet - caffeine

Function

Caffeine is absorbed and distributed very quickly. After absorption, it passes into the brain.

Caffeine does not accumulate in the bloodstream nor is it stored in the body. It is excreted in the urine many hours after it has been consumed.

Caffeine will not reduce the effects of alcohol, although many people still believe a cup of coffee will "sober-up" an intoxicated person.

Caffeine may be used as a treatment for migraine headaches and in relieving, for a short time, fatigue or drowsiness.

Food Sources

Caffeine is widely consumed. It is found naturally in the leaves, seeds, and fruits of more than 60 plants, including tea leaves, kola nuts, coffee, and cocoa beans. It is in coffee, tea, chocolate, cocoa and some colas.

Caffeine is frequently added to over-the-counter medications such as pain relievers, appetite suppressants, and cold medicines. Caffeine has no flavor and can be removed from a food by a chemical process called decaffeination.

Side Effects

Excessive caffeine intake can lead to a fast heart rate, excessive urination, nausea, vomiting, restlessness, anxiety, depression, tremors, and difficulty sleeping.

The effect of caffeine on health has been widely studied. In particular, the effects of caffeine on fibrocystic breast disease, heart and blood vessel disease, birth defects, reproductive function, and behavior in children has been closely examined. However, 1984 statement from the American Medical Association Council on Scientific Affairs stated, "Moderate tea or coffee drinkers probably have no concern for their health relative to their caffeine consumption provided other lifestyle habits (diet, alcohol consumption) are moderate as well." This statement emphasizes moderate caffeine use.

Abrupt withdrawal of caffeine may cause headaches, drowsiness, irritability, nausea, vomiting, and other symptoms. Reduce caffeine intake gradually to prevent any symptoms of withdrawal.

Recommendations

There is no human requirement for caffeine in the diet. Moderate caffeine intake, however, is not associated with any health risk. Three 8 oz. cups of coffee (about 250 milligrams of caffeine) per day is considered an average or moderate amount of caffeine. Ten 8 oz. cups of coffee per day is considered excessive intake of caffeine.

A child's caffeine consumption should be closely monitored. Although caffeine is safe to consume in moderation, it may negatively affect a child's nutrition. Caffeinated beverages may be replacing nutrient-dense foods such as milk. A child may also eat less because caffeine acts as an appetite suppressant. Caffeine can be completely restricted in a child's diet since there is no nutritional requirement for it. This may be necessary for a hyperactive child as caffeine is a stimulant.

Pregnant women, and people with coronary heart disease or peptic ulcers may be advised by their health care provider to restrict or avoid using caffeine.

Many drugs will interact with caffeine. Consult with your health care provider or pharmacist about potential interactions with caffeine whenever you take medications.

Review Date:8/6/2007
Reviewed By:Cynthia Dennison Haines, MD, family physician specializing in nutrition, fitness, and preventive health, St. John's Mercy Medical Center, St. Louis, MO, and Assistant Clinical Professor, St. Louis University's School of Medicine, Department of Community and Family Medicine.

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