Caffeine
(Ch. 13)
  1. THE HISTORY OF COFFEE IS LONG; COFFEE DRINKING HAS GONE THROUGH PERIODS OF BEING CONSIDERED BOTH GOOD AND BAD
  1. On a daily basis, more people use caffeine than any other psychoactive drug
  2. Caffeine belongs to the Xanthines class of chemicals. The Xanthines include; caffeine, theophylline and theobromine. They are methylated xanthines - very similar in structure and closely related to alkaloids.
  3. Legend has it that Arabian goatherd Kaldi is the figure who first discovered caffeine
  4. An Arabian medical book in 900 AD listed its beneficial uses
  5. Coffeehouses appeared by mid-17th century (1650) and were places to gather to talk
  6. Americans were tea drinkers until they boycotted tea because of the British Tax Act in 1765. Coffee became the new country's national drink
  7. The Middle East discovered that roasting green coffee beans improved the flavor, aroma and color
  8. Commercial roasting started in 1790 in NYC and the process gradually spread through the country
  9. In 1946 the annual per capita coffee consumption reached an all-time high of 20 pounds. The overall trend has been basically downhill since then, in spite of all the interest in expresso and specialty coffees.
  10. In the early 1950s, about 94% of American coffee came from Latin America - since then there has been a steady decline. Today less than half of the is grown in this hemisphere. Brazil is the principle exporter to the US, with Columbia second.
  11. Both countries grow arabica, which has a caffeine content of about 1%; and robusta, with a caffeine content of about 2%, is the variety grown in Africa and is usually of a lower grade and price
  12. The economics of coffee (its number two in international trade, behind oil) have as much to do with coffee consumption as does our changing lifestyle. Two things happen when prices go up: the quality of coffee decreases and people drink less coffee.
  13. In the 1980s, Americans began to drink more decaffeinated coffee and less regular coffee - to remove caffeine, unroasted beans are soaked in an organic solvent (usually methlene chloride), then roasted. The FDA placed limits on its residue (not to exceed ten parts per million)
  1. TEA IN THE UNITED STATES
  1. Tea comes from the tree, Camellia sinensis
  2. The first report of the use of tea is 360 A.D.Medically, there were claims tea cured many ills, but claims were also made that it caused harm
  3. In 1600 the English East India Company was formed, and Queen Elizabeth gave the company a monopoly on everything from the east coast of Africa across the Pacific to the west coast of South America. Through the Stamp Act of 1766, enacted by Parliament, a tax was placed on tea. This made the colonists unhappy and they boycotted consumption of English tea. By now, the East India Company was in serere financial trouble and to aid the company, Parliament gave the company the right to sell tea in the American colonies without paying the tea tax and to sell the tea through its own agents, eliminating profits to the merchants in the colonies. These activities resulted in the Boston Tea Party of December 16, 1773 and the Revolutionary War.
  4. Today, most of the tea (~70%) that comes to America comes from the mountains of Sri Lanka, India or Indonesia. Pluckers select only the bud-leaf and the first two leaves at each new growth. The bud-leaf is called the flowering orange pekoe (refering to the size and quality of the tea leaf), and the second leaf is larger and called orange pekoe an the third and largest leaf is called pekoe.
  5. Leaves are dried, rolled to crush the cells in the leaf and placed in a cool damp place for oxidation to occur - this turns the green leaves to a bright copper color (and now referred to as black tea - 98% of the tea that Americans consume). Nonoxidized leaves are packaged and sold as green tea
  6. In 1902 iced tea was sold for the very first time at the Louisiana Purchase Exposition in St. Louis and tea was placed in bags for brewing.
  7. The largest seller of tea in America is the Lipton Tea Company
  8. Tea also contains theophylline which is very effective at relaxing the bronchial passages
  1. CAFFEINE IS INCLUDED IN MANY FORMS OF FOOD OR DRINK
  1. Chocolate is made from the Theobroma cacao bush. It contains caffeine, but its active ingredient is theobromine - a xanthine that has physiological actions that closely parallel those of caffeine but are less potent in its effects on the CNS. The average cup of cocoa contains about 200 mg of theobrimine but only 4 mg of caffeine
  2. In 1847 the first chocolate bars appeared; and in 1876 milk chocolate was invented and sold by the Nestle company. By FDA standards, milk chocolate must contain at least 12% milk solids
  3. Many soft drinks contain large amounts of caffeine. Today soft drinks cannot contain more than 0.02% of caffeine (~0.2 mg/ml; or 6 mg/oz.). Soft drinks with high caffeine content are very popular among  children and teenagers causing concern about the potential for behavioral disturbance and for dependency.
  4. Caffeine is common in several over-the-counter drugs
  1. CAFFEINE CAUSES SEVERAL PHYSIOLOGICAL AND BEHAVIORAL EFFECTS
  1. The three xanthines have similar effects on the body, but caffeine has the graetest effect. Theobromine has almost no stimulant effect on the CNS and skeletal muscle. Theophylline is the most potent, and caffeine the least potent agent on the cardiovascular system. Caffeine has been the most extensively studied.
  2. It causes dependence and tolerance, although tolerance is generally low grade. The reinforcing effect of caffeine contributes to the psychological dependence. There is also physical dependence as well.
  3. caffeine and the other xanthines block the brain's receptors for adenosine, a neurotransmitter. Adenosine normally acts in several areas of the brain to produce behavioral sedation by inhibiting the release of other neurotransmitters. Caffeine's stimulant action results from blocking the receptors for this inhibitory effect.
  4. Physiological effects include CNS and respiratory stimulation as well as dilation of the bronchial tubes. There is a strong relationship between the mood-elevating effect of caffeine and the extent to which it will keep an individual awake. Higher dose levels (500 mg) are needed to affect the autonomic centers of the brain, and heart rate and respiration can increase at this dose.
  5. Caffeine acts directly on the vascular muscles to cause dilation, wheras stimulation of the autonomic centers results in constriction of blood vessels.
  6. Behavioral effects are somewhat inconclusive at this time although caffeine does seem to produce an anxiety-like reaction
  1. THE USE OF CAFFEINE HAS LED TO SOME COCERN IN THE MEDICAL PROFESSION
  1. It is important to point out that there is not yet clear evidence that moderate caffeine consumption is dangerous, the scientific literature has investigated the possible effects of caffeine in cancer, benign breast disease, reproduction and heart disease. The problem in knowing for certain about some of these things is that epidemiological research on caffeine consumption is difficult to do well. Coffee drinkers tend to do "other" things - smoke, work at jobs that require long hours without sleep, etc. - is it the activity that produces the effect, or is it caffeine?
  2. Although suspected, no link has been found between coffee consumption and pancreatic cancer or fibrocystic breast disease
  3. Caffeine may be linked to difficulty in becoming pregnant, to miscarriages, and to slowed fetal development
  4. Drinking 5 or more cups of coffee daily can increase the risk of heart disease - based upon increase heart rate, increased blood pressure and the increase in blood cholesterol levels.