Consumed in behaviorally active doses, caffeine is an alkaloid found naturally in coffee beans, cacao beans and the tea plant (Camellia sinensis). It is also added to some soft drinks and energy drinks
Coffee. The most popular drink in the world
An estimated 2.25 billion cups / day drunk worldwide.
66% of adult U.S. population drink an average 3.1 cups each day. (~517 million cups / day)
Tea, chocolate and coffee either directly contain the stimulants theobromine and theophylline or they are metabolized from caffeine(the liver metabolizes caffeine into 10% theobromine and 4% theophylline)
Controversial studies include those on caffeine's both positive and negative effects on cancer, hypertension, Type 2 diabetes, liver cirrhosis, cardiovascular disease, pregnancy complications, eating disorders, depressive disorders (including suicidal effects)
For example:
Some studies claim regular coffee consumption reduces the risk for heart disease and diabetes.
Studies conflict on mental health.
Lesk, Valerie E.; Womble, Stephen P. Caffeine, Priming, and Tip of the Tongue: Evidence for Plasticity in the Phonological System. Behavioral Neuroscience, Vol 118(3), Jun 2004, 453-461. http://news.bbc.co.uk/2/hi/health/3909085.stm
Another small study (n= 15) - found that a couple cups of coffee per day could improve your short-term memory
Koppelstaetter, F et al. "Influence of Caffeine Excess on Activation Patterns in Verbal Working Memory"
Linus Pauling Institute on Health Effects of Coffee/Caffeine
However, as with most foods, the health. Beneficial effects of caffeine are generally seen when:
Christian Science Monitor December 29, 2009
Generally, health benefits are small compared to its detrimental effects. Any professed benefits can be achieved by other, less risky methods;
Experts generally recommend an intake of less than ~300mg of caffeine each day
| Caffeine in some popular Drinks / Foods | |
|---|---|
| 6 oz drip-brewed Robusta coffee | 200 mg |
| 6 oz drip-brewed Arabica coffee | 130 mg |
| 1 oz shot espresso coffee | 50 mg |
| 6 oz instant coffee | 100 mg |
| 6 oz 97% decaf coffee | 6 mg |
| 6 oz Euro-standard decaf coffee | 16 mg |
| 6 oz hot cocoa | 15 mg |
| 6 oz soda drink (Coke, Pepsi and Mountain Dew) | 26 mg |
| 6 oz green tea | 30 mg |
| 6 oz black tea | 60 mg |
| 6 oz bar dark chocolate | 100 mg |
| 6 oz bar milk chocolate |
50 mg |
Younger leaves and buds of tea plant (camellia sinensis) contain more caffeine per weight than older leaves and stems.
Regardless of its contraversially purported health benefits, caffeine is a powerful drug. As such its intake should be limited to less than 250-300 mg/day, or even avoided completely by some people, or at the very least should not consumed in the late afternoon or evening, which may cause insomnia;
Chronic caffeine consumption in excess of 250-300 mg / day can lead to a condition called CAFFEINISM. in additon to causing dependency (which can cause uncomfortable withdrawal symptoms), the undesireable symptoms of caffeinism can include:
Iancu I, Olmer A, Strous RD (2007). "Caffeinism: History, clinical features, diagnosis, and treatment". In Smith BD, Gupta U, Gupta BS. Caffeine and activation theory: effects on health and behavior. CRC Press. pp.331-344. ISBN 978-0-8493-7102-
With repetitive use, physical dependence or addiction are likely to occur
Regular consumption of the equivalent dose level of only 1 cup of coffee (or 3 cans of caffeinated soda per day) can cause caffeine addiction that would trigger withdrawal symptoms;
Studeville, George. "Caffeine Addiction Is a Mental Disorder, Doctors Say."National Geographic. Jan. 15, 2010.
Overtime the stimulatory effects of caffeine are substantially reduced. Some people (especially heavy caffeine users) develop a tolerance to its effects
Some coffee drinkers develop tolerance to its sleep-disrupting effects. Some do not.
Fredholm BB, Bättig K, Holmén J, Nehlig A, Zvartau EE (1999). "Actions of caffeine in the brain with special reference to factors that contribute to its widespread use". Pharmacol. Rev. 51(1): 83-133. PubMed
Symptoms include: headache, irritability, fatigue/drowsiness, "downer" mood changes, inability to concentrate, muscle stiffness/pain, flu-like feelings, pain in stomach and/or upper body, nausea/vomiting, craving for coffee/tea; may occur 12-24 hours after discontinuation of caffeine intake, peak at roughly 48 hours, and usually last from 2 to 9 days.
Juliano LM, Griffiths RR (2004). A critical review of caffeine withdrawal: empirical validation of symptoms and signs, incidence, severity, and associated features". Psychopharmacology (Berl.) 176(1): 1-29. doi:10.1007/s00213-004-2000-x. PMID15448977.
The fact that these symptoms occur when caffeine consumption is stopped should be cause for concern
Cause of caffeine withdrawal headache has an ironic twist. Habitual caffeine intake causes brain's blood vessels to stay constricted, thereby reducing the normal, healthy blood flow to the brain. When caffeine intake stops, the blood vessels dilate to resume their normal blood flow, which causes the throbbing pain until the brain again gets used to the normalcy.
Caffeine is possibly consumed to stave off withdrawal symptoms rather than for enjoyment. There is also the possibility of a circling loop whereby caffeine causes insomnia that leaves you waking up tired and thus needing more caffeine as a stimulant
Griffiths R, Juliano (2004): Psychopharmacology; A Critical Review of Caffeine Withdrawal; Sept. 21, 2004
Post-operative headaches are now attributed to caffeine withdrawal (not anaesthesia)
Decaffeination process for tea and coffee loses their health-beneficial antioxidant bioflavonoids
The direct solvent method is preferred by manufacturers because it's the most affordable and has the capacity to remove the highest percentage of caffeine. CO2 and Swiss water processing are safer options since they do not utilize hazardous chemical solvents.
Direct solvent method - a technique that uses methylene chloride (which the FDA banned in hairsprays and cosmetics due to inhalation risks), coffee oil, or ethyl acetate (a low-toxicity solvent naturally present in wines) to dissolve and extract caffeine from the coffee.
Also, "According to a report published on August 9, 1985, in the Journal of the American Medical Association, studies of rats fed regular and decaffeinated coffee (at doses equivalent to 70 or 80 cups of coffee per day) or fed methylene chloride in their drinking water (at doses equivalent to 125,000 to 6,250,000 cups of decaffeinated coffee per day) showed no evidence of carcinogenicity. . . . Hence, scientific evidence suggests that methylene chloride is safe for use as a solvent in decaffeinating coffee."
CO2 (technically known as supercritical fluid extraction) - uses a pressurized method with a water or charcoal filtration to remove the caffeine.
Swiss Water Process. Simply uses water and a carbon filtration system to remove the caffeine.
Caffeine is rapidly and 99% absorbed. First in the stomach and small intestine and then distributed to all tissues, including through the blood brain barrier to the brain and across the placental barrier.
At typical daily intake levels, caffeine opposes the neuroinhibitory effect of adenosine by blocking adenosine receptors - Adenosine (a compound endogenous to the body) mostly inhibits the response of neurons to neurotransmitters, thus the effects of adenosine antagonism by caffeine are generally stimulatory.
James JE. Critical review of dietary caffeine and blood pressure: a relationship that should be taken more seriously. Psychosom Med. 2004;66(1):63-71. (PubMed)
Fredholm BB, Battig K, Holmen J, Nehlig A, Zvartau EE: Actions of caffeine in the brain with special reference to factors that contribute to its widespread use. Pharmacol Rev 51:83-133, 1999 Abstract/FREE Full Text
Caffeine intake aggravates physical, mental, and emotional stress
Caffeine and other ingredients found in coffee (also in decaffeinated coffee) have been shown to increase stress response - Caffeine elevates the catecholamines (hormonal neurotransmitters) EPINEPHRINE and NOREPINEPHRINE, and the stress hormone CORTISOL, creating an emergency "fight or flight" reaction in the body, including increased heart rate, blood pressure, and a sense of "emergency alert", often seen as hyperactivity, anxiety, or panic disorder.
William R. Lovallo , Noha H. Farag, Andrea S. Vincent, Terrie L. Thomas, Michael F. Wilson. Cortisol responses to mental stress, exercise, and meals following caffeine intake in men and women. Pharmacology Biochemistry and Behavior, Volume 83, Issue 3, March 2006, pp. 441-447. [ScienceDirect]
William R. Lovallo, Thomas L. Whitsett, Mustafa al'Absi, Bong Hee Sung, Andrea S. Vincent, Michael F. Wilson. Caffeine Stimulation of Cortisol Secretion Across the Waking Hours in Relation to Caffeine Intake Levels. Psychosomatic Medicine September 1, 2005 vol. 67 no. 5 734-739 [Abstract]
Caffeine inhibits our "feel good" brain messenger GABA (Gamma-aminobutyric acid), which plays an important role in mood and stress management. Caffeine does this indirectly as a domino effect of blocking adenosine receptors.
Low GABA activity causes nerve cells to "fire"too often, causing anxiety disorders;
Lack of GABA can trigger stress or emotional eating - which leads to weight gain, and also the reason why you go for the ice cream or cookies when feeling down;
The body's magnesium is depleted by production of the stress hormones CORTISOL and the catecholamines EPINEPHRINE and NOREPINEPHRINE - which prepare the body for the "fight-or-fight"response and are produced when caffeine increases stress levels in the body
Low magnesium levels wreak havoc in the cardiac system and most all other areas of the body
Limiting your caffeine intake can better control your appetite and help curb food cravings.
Caffeine stimulates appetite and food cravings
High-dose caffeine (~6 cups coffee) produces temporary IR by inducing "fight-or-flight"response - caffeine raises blood sugar to supply the energy needed for running from the proverbial saber-toothed tiger or else fighting off the foe. With chronic caffeine consumption this can lead to IR with the ongoing production of INSULIN to remove the never-ending supply of glucose
IR is a condition that reduces the body's ability to use INSULIN effectively, resulting in a build-up of glucose and INSULIN in the blood - increasing the risk of developing Type II Diabetes and numerous other health problems
Caffeine can decrease insulin sensitivity in humans. Diabetes Care, 2002, Vol 25, Iss 2, pp 364-369. GB Keijzers, BE DeGalan, CJ Tack, P Smits. Smits P, Univ Nijmegen, Med Ctr, Dept Pharmacol Toxicol 233, POB 9101, NL-6500 HB Nijmegen, NETHERLANDS
Diabetics should avoid or cut back on caffeine. Lane et al found that although caffeine did not affect blood sugar of Type 2 diabetics during fasting, a 125 mg dosebefore a meal did significantly impair sugar metabolism of the meal compared to placebo.
Lane, J. Diabetes Care, August 2004; vol 27. News release, Duke University. National Sleep Foundation. WebMD Medical News: "Specialty Coffee's Caffeine Jolt Varies."
Caffeine intake can cause insomnia and sleep deprivation in some people - both of which have been found to increase IR.
Snel J (1993) Coffee and caffeine: Sleep and wakefulness. in Coffee, Caffeine and Health, ed Garattini S (Raven Press, New York), pp 255-290. ResearchGate
Except short-term for those who have not formed a tolerance for it
Sufficient doses of caffeine increase urination - but regular consumption of caffeine develops immunity to this diuretic effect
Armstrong LE, Casa DJ, Maresh CM, Ganio MS. Caffeine, fluid-electrolyte balance, temperature regulation, and exercise-heat tolerance. Exerc Sport Sci Rev. 2007 Jul;35(3):135-40. [PubMed]
Maughan RJ, et al. Caffeine ingestion and fluid balance: A review. Journal of Human Nutrition and Dietetics. 2003;16:411. [Online Link]
Even 1 small cup of coffee (~100 mg caffeine) can stimulate gastric acid production enough to irritate a stomach ulcer.
University of Utah College of Pharmacy
Increased stomach acid after a meal can, however, enhance protein digestion
Caffeine ==> Stress + Aging + Degeneration + Adrenal Exhaustion
Type A's face a double whammy re: caffeine intake and depletion of vital Mg
(1) Type A's /Stressed types are more likely to indulge in caffeine
(2) Both the caffeine and the stress will deplete Mg (research has found that Type A's lose significant amounts of Mg when under stress, compared to easy-going Type B's)
Overstimuated adrenal glands ▲ ==> Adrenal "burn-out" and depleted adrenal hormones (Necessary for vitality)
Body uses PROGESTERONE as a substitute for depleted adrenal hormones -sufficient PROGESTERONE is then not available to effectively do its job of balancing estrogen, which can lead to estrogen dominance with all its inherent risks, including osteoporosis and cancer
Caffeine disrupts calcium ion flow through caffeine-sensitive calcium release channels in skeletal muscle -causing skeletal muscle to contract or spasm
Tension in neck, back, shoulder, wrist (CTS/carpal tunnel syndrome), muscle pain after exertion. Relates to increased sensitivity to caffeine. Reduce tension by eliminating caffeine.
Caffeine has a powerful vasoconstrictive effect in the brain. 250mg caffeine consumed by motheris enough to reduce cerebral blood flow by 30% in a preterm infant;
Hoecker C, Nelle M, Poeschl J, Beedgen B. Linderkamp O (2002): Caffeine impairs cerebral and intestinal blood flow velocity in preterm infant. Pediatrics 109: 784-787.
Headache caused by caffeine, ultimately then promoted by pain-meds taken. Caffeine depletes blood levels of ionized magnesium, whose low levels are noticed in headache sufferers. Analgesics are given to reduce pain, but > 95% of analgesics contain caffeine. Analgesics/caffeine keep cerebral blood vessels constricted until the supply stops, then the dilation brings on another headache, keeping you an ongoing analgesic "user". The sensible solution is to simply stop the caffeine.
Caffeine raises homocysteine levels. Involved in low-level chronic inflammation seen in heart disease, blood vessel degeneration in the eyes and a wide range of serious conditions.. Caffeine interferes with your body's ability to use folate, and vitamins B12 and B6. Your body needs these nutrients in order to keep your homocysteine level in the healthy range.
Increases blood pressure. An added detriment to people with T2D, who already have impaired peripheral circulation;
Decreases oxygen delivery - which:
(1) Decreases cellular energy production
(2) Reduces oxygen to the brain causing headaches
