The World of Caffeine (67 page)

87
. Barry Steven Cohen, “Does Caffeine Have An Ergogenic Benefit On Low Intensity Exercise Performance in a Warm Environment?”
unpublished manuscript, p. 56, note 110.

88
.
Ibid.,
p. 58.

1
. H.O.G.Holck, “Effect of Caffeine on Chess Problem Solving,”
Journal of Comparative Psychology
(1933): 301–11.

2
. J.E.Barmack, “The Time of Administration and Some Effects of 2 grams of Alkaloid Caffeine,”
Joumal of Experimental Psychology
27 (1940): 690–98.

3
. Garattini,
Caffeine, Coffee, and Health,
p. 296.

4
. The information-processing approach consists of studying the flow of information through the system, monitoring the sequence of processing and transformations between input and output. In its various forms, the information-processing metaphor has guided research on quite complex behavior and has allowed the generation of extensive theories concerning the nature of such phenomena as perception, memory, attention, problem solving, language, and decision making. Garattini,
Caffeine, Coffee, and Health,
p. 301.

5
. A.F.Sanders, “Towards a Model of Stress and Human Performance,”
Act Psychology
1, no. 53 (1983): 61–97.

6
. In a visual-search task, caffeine hurt performance when the target was six letters but helped when it was only two. In a recent study, the ability to solve a maze was unaffected by caffeine, while caffeine promoted the regularity and fluency of letter cancellation task performance.

7
. A.C.Bittner et al., “Performance Evaluation Tests for Environmental Research (PETER): Evaluation of 114 measures,”
Precept. Mot.
Skills
63 (1986): 683–708.

8
. This analysis is apparently is in accord with the Yerkes-Dodson principle. See Jack James,
Caffeine and Health,
p. 250.

9
. M.S.Humphreys and W.Revelle, “Personality, Motivation, and Performance: A Theory of the Relationship between Individual Differences and Information Processing,”
Psychological Review
91 (1984): 153–84.

10
. V.E.Mitchell et al., “Drugs and Placebos: Effects of Caffeine on Cognitive Performance,”
Psychological Reports,
35 (1974): 875–83.

11
. Segal’s findings were presented in a proceeding of the National Academy of Sciences, October 1999.

12
. “In the context of learning and memory, it is interesting to note that xanthines, such as theophylline, enhanced long-term potentiation, an elector-physiological model of memory” in guinea pigs. Y.Tank et al., “Effect of Xanthine Derivatives on Hippocampal Long-term Potentiation,”
Brain Research
522 (1990): 63–68.

13
. Jack James,
Caffeine and Health
, p. 305.

14
.
Ibid.,
p. 248.

15
. J.D.Roache and R.R.Griffiths, “Interactions of Diazepam and Caffeine: Behavioral and Subjective Dose Effects in Humans,”
Pharmacology, Biochemistry and Behavior
26 (1987): 801–12.

16
. B.H.Jacobson and B.M.Edgley, “Effects of Caffeine on Simple Reaction Time and Movement Time,”
Aviation, Space, and
Environmental Medicine
58 (1987): 1153–56.

17
. W.J.Baker and G.C.Theologus, “Effects of Caffeine on Visual Monitoring,”
Journal of Applied Psychology
56 (1972): 422–27.
E.G.Regina et al., “Effects of Caffeine on Alertness in Simulated Automobile Driving”
Journal of Applied Psychology
59 (1974):
483–89.
A 1993 study of ten coffee drinkers at Wake Forest University, Winston-Salem, North Carolina, found that caffeine does improve certain reflex brain functions. Subjects drank one or two cups of coffee twenty minutes before beginning “eyeblink startle reflex” tests, consisting of short bursts of “white noise” images. Schiacato, lead researcher, said that the blink reflexes, the sort of involuntary responses that occur too fast for voluntary control, of the coffee drinkers sustained a performance better than the non-drinkers. When exposed to redundant or repeated stimuli, involuntary responses taper off as a result of fatigue. In effect, the brain learns to ignore the stimulus. If caffeine can slow this “ignoring” response, as these experiments suggest, it may increase performance of repetitive tasks, such as driving late at night and seeing the same highway lights, white lines, and road surface, over and over. (“Cup Of Coffee Really Does Perk Up Brain,”
USA Today
)

18
. Michael H.Bonnet et al., “The Use of Caffeine Versus Prophylactic Naps in Sustained Performance,”
Sleep
18 (2): 97–104. (The American Sleep Disorders Association and Sleep Research Society)

19
. Jack James, “Does Caffeine Enhance or Merely Restore Degraded Psychomotor Performance?”
Neuropsychobiology
30 (1994): 124– 25.

20
. James,
Caffeine and Health,
p. 290.

21
. W.H.Loke et al., “Caffeine and Diazepam: Separate and Combined Effects on Mood, Memory, and Psychomotor Performance,”
Psychopharmacology
87 (1985): 344–50. See also Loke, “Effects of Caffeine on Mood and Memory,”
Physiology and Behavior
44 (1988): 367–72.

22
. James,
Caffeine and Health,
p. 294.

23
. M.A.Lee, “Anxiety and Caffeine Consumption in People with Anxiety Disorders,”
Psychiatry Research
15 (1985): 211–17.

24
. J.F.Neil, “Caffeinism Complicating Hypersomnic Depressive Syndromes,”
Comprehensive Psychiatry
19 (1978): 377–85.

25
. D.R.Cherek, “Effects of Caffeine on Human Aggressive Behavior,”
Psychiatry Research,
8 (1983): 137–45, and “Regular or Decaffeinated Coffee and Subsequent Human Aggressive Behavior”
Psychiatry Research
11 (1984): 251–58.

26
. Roache and Griffiths (see note 15).

27
. Sleep and wakefulness occur as phases of a cycle called the “circadian rhythm,” with a natural length of about twenty-five hours, a peak in the late afternoon, and a trough between three and four in the morning. Though the pattern of the circadian rhythm is determined primarily from within, external factors, such as the alternation of light and dark and habits of work and leisure, conjoin to “squash” it into twenty-four hours.

28
. These characteristic regular patterns in the sleep state, as measured by the EEG, are termed the “sleep structure” and are taken to represent the quality and depth of sleep.

29
. Edwards,
America’s Favorite Drug,
p. 71.

30
. As Jan Snel suggests in his paper “Coffee and Caffeine: Sleep and Wakefulness,” the “effects of caffeine on the sleep-wake cycle depend both on the level of arousal, determined by more or less constant ‘trait’ factors, such as age and personality, and by short-term ‘state’ factors, such as time of day, fatigue, or nutritional items” (Garattini,
Caffeine, Coffee, and Health,
p. 256).

31
. Edwards,
America‘s Favorite Drug,
p. 71.

32
. Quentin R. Regestein, “Pathologic Sleepiness Induced by Caffeine,”
American Journal of Medicine
87 (1989): 587–88.

33
. A. Goldstein, “Wakefulness Caused by Caffeine,”
Archiv fur Experimentelle Pathologie und Pharmakologie
248 (1964): 269–78.

34
. A recent fad in the United States, using the hormone melatonin to sleep better, as well as to stay young and cure most of humanity’s ills, is interesting for our subject, because caffeine may be a potent suppressor of it. Melatonin is thought to be the natural hormone that some say regulates our internal time clock and sleep patterns. Twenty-five subjects who were given 200 mg of caffeine tablets experienced a significant reduction in melatonin levels in their blood that persisted for eight hours. The peak serum levels of melatonin averaged 25 mg/ml without caffeine but only 14 mg/ml when caffeine had been ingested. According to Jo Robinson, the co-author of a recent authoritative book on melatonin, “If you drink coffee and are under bright lights, you will get an even greater reduction in melatonin levels. Taking supplemental melatonin will offset this effect.” V.K.P.Wright, “Effects of Caffeine, Bright Lights, and Their Combination on Nighttime Melatonin,”
Sleep Research
24 (1995): 458.

1
. N.Bridge, “Coffee-drinking as a Frequent Cause of Disease,”
Trans Assoc Am Physicians
8 (1893): 281–88.

2
. R.R.Griffiths et al., “Human Coffee Drinking: Manipulation of Concentration and Caffeine Dose”
Journal of the Experimental
Analysis of Behavior
45 (1986): 133–48.

3
. K.Silverman et al., “Withdrawal Syndrome after the Double-Blind Cessation of Caffeine Consumption,”
NEJM
327 (1992): 1109–14.

4
. See Spiller,
Methylxanthine Beverages,
and Jack James,
Caffeine and Health,
p. 33.

5
. R.Reeves et al., “Quantitative Changes During Caffeine Withdrawal,” presented at the annual meeting of the College of Problems on Drug Dependence, Palm Beach, Florida, June 1994.

6
. Conversation with an anonymous registered nurse. She suggested that clinics performing ambulatory or outpatient surgeries and the American Society of Post Anesthesia Nurses might be able to provide more information about this effect.

7
. J.D.McGowan et al., “Neonatal Withdrawal Symptoms after Chronic Ingestion of Caffeine,”
Soutbern Medical Journal
81 (1988):
1092–94.

8
. Eric Strain et al., “Caffeine Dependence Syndrome: Evidence from Case Histories and Experimental Evaluations,” JAMA 272 (1994): 1043–48.

9
. For an expansion of this viewpoint, see Griffiths et al., “Caffeine Dependence,”
JAMA,
October 1994.

10
. Garattini,
Caffeine, Coffee, and Health,
p. 213.

11
. R.R.Griffiths et al., “Relative Abuse Liability of Triazolam: Experimental Assessment in Animals and Humans,”
Neuroscience and
Biobehavioral Reviews
9 (1985): 133–51.

12
. R.R.Griffiths and P.P.Woodson, “Reinforcing Properties of Caffeine: Studies in Humans and Laboratory Animals,”
Pharmacology,
Biochemistry, and Behavior
29 (1988): 419–27.

13
. J.R.Hughes et al., “Indications of Caffeine Dependence in a Population-Based Sample.” In
Problems of Drug Dependence,
ed.
L.S.Harris. Washington, D.C.: U.S. Government Printing Office, NIDA Research Monograph #132 (NIH Publication No. 93–3505), pp. 19–28, 1993.

14
. Stephen J.Heishman et al., “Stimulus Functions of Caffeine in Humans: Relation to Dependence Potential,”
Neuroscience and
Biobehavioral Reviews
16 (1992): 281.

15
. Spiller,
Methylxanthine Beverages,
p. 287.

16
. R.R.Griffiths et al., “Human Coffee Drinking: Reinforcing and Physical Dependence Producing Effects of Caffeine,”
Journal of
Pharmacology and Experimental Therapeutics
239 (1986): 416–25.

17
. J.T.Rugh, “Profound Toxic Effects from the Drinking of Large Amounts of Strong Coffee,”
Medical and Surgical Reporter
75 (1896): 549–50.

18
. “A Letter to the Editor of
JAMA,
” 62 (1914): 1828–29, by Otis Orendorff, M.D., Canon City, Colorado.

19
. Water intoxication is a result of lowering the sodium balance in the blood, creating sensations similar to drunkenness, and can be achieved only by gulping at least twenty-four quarts of water a day. It’s a transient pleasure at best, vanishing when, as quickly occurs with urination, the body adjusts this level to normal. According to one neuropharmacologist’s report, a man actually died from drinking too much water while high on the drug ecstasy at a rave party.
By the way, someone must have been eating tea as well, at least in the nineteenth century, to judge by Alcott’s comments in 1839 “that the eaters of tea grounds are especially noted for this leathery complexion…as a considerable part of the tanning properties remains in the tea leaves after it has been infused in the usual manner.” William Alcott,
Tea and Coffee,
Boston 1839, p.
22.

20
. Jack James,
Caffeine and Health,
p. 69.

21
.
Ibid.,
p. 68.

22
. S.Jokela and A.Vartiainen, “Caffeine Poisoning,”
Acta Pharmacologica et Toxicologica
15: (1959): 331–34.

23
. J.E.Turner and R.H.Cravey, “A Fatal Ingestion of Caffeine,”
Clinical Toxicology
10, no. 3 (1977): 341–44.

24
. R.V.Nagesh and K.A.Murphy, “Caffeine Poisoning Treated by Hemoperfusion,”
American Journal of Kidney Diseases
12 (1988):
316–18. See also Jack James,
Caffeine and Health,
p. 68.

25
. R.L.Alsott et al., “Report of a Human Fatality Due to Caffeine,”
Journal of Forensic Sciences
14 (1972): 135–37. See also J.Bryant, “Suicide by Ingestion of Caffeine—Letter”
Archives of Pathology and Laboratory Medicine
105 (1981): 685–86.

26
. P.B.Kulkarni and R.D.Dorand, “Caffeine Toxicity in the Neonate,”
Pediatrics
64 (1979): 254–55.

27
. V.J.M.Dimaio and J.C.Garriott, “Lethal Caffeine Poisoning in a Child,”
Forensic Science
3 (1974): 275–78.

1
. We don’t know if any autopsy data is available, but probably there is caffeine in most corpses.

2
. Pomet, Lemery, and Tournefort,
A Compleat History of DRUGGS,
“Of FRUITS,” Of Chocolate, p. 132.

3
. Spiller,
Methylxanthine Beverages,
p. 188.