Caffeine is a commonly consumed drug. It is found in various beverages such as tea, coffee, cola-flavored carbonated beverages, and in some chocolate products. Caffeine is also added to a variety of other carbonated beverages and is an ingredient in a number of non-prescription drugs such as headache, cold, allergy, pain relief, and stay-awake pills. About 80% of the adult population in the U.S consume caffeine, and about 20% consume over 350 mg daily --- a level sufficient to cause physical dependency.
The amount of caffeine in a cup of tea or coffee is affected by the method of preparation. An average cup of instant coffee contains about 65 mg ,while brewed coffee contains about 110 mg/cup. Tea and most caffeinated soft drinks contain 20-65 mg/serving. Hot chocolate beverages contain about 5 mg/cup, while chocolate candy may contain between 10-40 mg per 2 oz. bar.
Is caffeine harmful?
Physiological effects of caffeine can be seen in adults at doses of only 100-200 mg. This is readily achieved with 1-3 cups of coffee. On a body weight basis, children ages 1-5 years, are the heaviest consumers of caffeine. A child consuming one can of caffeinated soda receives a caffeine equivalent of 4 cups of coffee for an adult.
Caffeine is readily absorbed by the body, with blood levels peaking about 30 minutes after ingestion. The clearance rate from the blood varies from several hours in an adult to several days in a newborn. The clearance rate is decreased by pregnancy and use of oral contraceptives. Smoking, on the other hand, appears to increase the rate at which caffeine is cleared from the body. Hence, caffeine intake should be greatly reduced or eliminated by persons trying to quit smoking, so as to prevent increased caffeine levels in the blood and the possible increased craving for nicotine.
Methylxanthines, such as caffeine may cause physical as well as physiological damage. The reason for this is the chemical nature of this chemical. Methylxanthines have the ability to alter the very protoplasm of cells, and to attack or concentrate in cells for an unknown period of time.
Caffeine can produce many effects including:
Elevated blood sugar (giving a feeling of an energy surge)
Elevated blood fats
Increased blood pressure
Stimulate central nervous system
Irregular heart
Increased urinary calcium and magnesium losses
Increased stomach acid secretion
Tremors, irritability and nervousness
Insomnia and disruption of sleep patterns
Anxiety and depression
Heightened symptoms of premenstrual syndrome (PMS)
Imperfect balance
Apparently all the Methylxanthines step up cell growth in certain glandular tissues. Since they pose an interference in the normal activity of certain enzymes, they act as poisons. True to their chemical classification as cellular toxins, Methylxanthines shut off enzyme signals, in this instance the signal to stop growing. As a result, certain glandular tissues under the influence of caffeine may begin developing cysts and fibrous tumors especially in the breast, the so-called fibrocystic disease. It seems wise to advise women everywhere to cut out the use of methylxanthines as a breast cancer control measure.
