Caffeine
Frequently Asked Questions - Part 1
Caffeine FAQ By Alejandro Lopez-Ortiz
- Coffee is the second most valuable legal item of international trade in the world (after oil)
- More than twenty million people around the world are employed by the coffee industry
- Coffee is the largest food import to the United States
A. Caffeine And Related Products
1. How much caffeine is there in [drink/food/pill]?
According to the National Soft Drink Association, the following is the caffeine content in mgs per 12 oz can of soda:
Jolt 100.0
Sugar-Free Mr. Pibb 58.8
Mountain Dew 55.0
Diet Mountain Dew 55.0
Mello Yellow 52.8
Tab 46.8
Coca-Cola 45.6
Diet Cola 45.6
Shasta Cola 44.4
Shasta Cherry Cola 44.4
Shasta Diet Cola 44.4
Mr. Pibb 40.8
OK Soda 40.5
Dr. Pepper 39.6
Pepsi Cola 37.2
Aspen 36.0
Diet Pepsi 35.4
RC Cola 36.0
Diet RC 36.0
Diet Rite 36.0
Canada Dry Cola 30.0
Canada Dry Diet Cola 1.2
7 Up 0
By means of comparison, a 7 oz cup of coffee has the following caffeine (mg) amounts, according to Bunker and McWilliams in _J Am Diet_ 74:28-32, 1979:
Drip 115-175
Espresso 100mg of caffeine
1 serving (1.5-2oz)
Brewed 80-135
Instant 65-100
Decaf, brewed 3-4
Decaf, instant 2-3
tea, iced (12 ozs.) 70
tea, brewed, imported 60
tea, brewed, U.S. 40
tea, instant 30
The variability in the amount of caffeine in a cup of coffee or tea is huge even if prepared by the same person using the same equipment and ingredients day after day.
Reference Variability in caffeine consumption from coffee and tea: Possible significance for epidemiological studies by B. Stavric, R. Klassen, B. Watkinson, K. Karpinski, R. Stapley, and P. Fried in Foundations of Chemical Toxicology, Volume 26, number 2, pp. 111-118, 1988 and an easy to read overview, Looking for the Perfect Brew by S. Eisenberg, Science News, Volume 133, April 16, 1988, pp. 252-253.
Quote from the lab manual:
Caffeine is present in tea leaves and in coffee to the extent of about 4%. Tea also contains two other alkaloids, theobromine and theophylline. These last two relax the smooth muscles where caffeine stimulates the heart and respiratory systems.
Steve Dyer says:
Theobromine is virtually inactive. Both caffeine and theophylline stimulate the heart and respiratory systems and relax smooth muscle (such as in the bronchioles). Theophylline is somewhat more toxic and somewhat less powerful a CNS stimulant than caffeine, but they are more similar than different.
Other data on caffeine:
Cup of coffee 90-150mg
Instant coffee 60-80mg
Tea 30-70mg
Cola 30-45mg
Chocolate bar 30mg
Stay-awake pill 100mg
Vivarin 200mg
Cold relief tablet 30mg
The following information is from Bowes and Church's Food values of portions commonly used, by Anna De Planter Bowes. Lippincott, Phila. 1989. Pages 261-2: Caffeine.
Candy:
Chocolate mg caffeine
baking, unsweetened, Bakers (1 oz) 25
german sweet, Bakers (1 oz) 8
semi-sweet, Bakers (1 oz) 13
Choc chips
Bakers -- 1/4 cup (43 g) 13
german sweet, Bakers (1/4 cup) 15
Chocolate bar, Cadbury (1 oz) 15
Chocolate milk 8oz 8
Desserts:
Jello Pudding Pops, Choc (47 g) 2
Choc mousse from Jell-O mix (95 g) 6
Jello choc fudge mousse (86 g) 12
Beverages
3 teaspoons of choc powder mix 8
2 tablespoons choc syrup 5
1 envelope hot cocoa mix 5
Dietary formulas
ensure, plus, choc, Ross Labs (8 oz) 10
Cadbury Milk Chocolate Bar
More stuff:
Guarana Magic Power (common in Germany),
15 ml alcohol with
5g Guarana Seeds 250.0 mg
Guarana capsules with
500 mg G. seeds 25.0 mg / capsule
assuming 5% caffeine in seeds
as stated in literature
Guarana soda pop is ubiquitous in Brazil and often available at tropical groceries here. It's really tasty and packs a wallop. Guarana wakes you up like crazy, but it doesn't cause coffee jitters.
It is possible that in addition to caffeine, there is some other substance in guarana that also produces an effect, since it 'feels' different than coffee. Same goes for mate.
2. Is it true that espresso has less caffeine than regular coffee?
Yes and no. An espresso cup has about as much caffeine as a cup of dark brew. But servings for espresso are much smaller. Which means that the content of caffeine per millilitre are much higher than with a regular brew.
Moreover, caffeine is more quickly assimilated when taken in concentrated dosages, such as an espresso cup.
The myth of lower caffeine espresso comes from the fact that the darker roast beans used for espresso do have less caffeine than regularly roasted beans (roasting breaks up the caffeine in the beans).
But espresso is prepared using pressurized steam which extracts a higher percentage of caffeine from the ground beans than regular drip.
Here's the caffeine content of Drip/Espresso/Brewed Coffee:
Drip 115-175
Espresso 100 (1 serving - 1.5-2oz)
Brewed 80-135
3. Is it true that tea has no caffeine/What is theine, theobromine, etc?
From Principles Of Biochemistry, Horton and al, 1993. Caffeine is sometimes called theine when it's in tea. This is probably due to an ancient misconception that the active constituent is different.
Theophylline is present only in trace amounts. It is more diuretic, more toxic and less speedy. Caffeine 1,3,7-trimethylxanthine Theophylline 1,3-dimethylxanthine Theobromine 3,7-dimethylxanthine Coffee and tea contain caffeine and theophylline, respectively, which are me thylated purine derivatives that inhibit cAMP phosphodiesterase.
In the presence of these inhibitors, the effects of cAMP, and thus the stimulatory effects of the hormones that lead to its production, are prolonged and intensified. Theobromine and theophylline are two dimethyxanthines that have two rather than three methyl groups.
Theobromine is considerably weaker than caffeine and theophylline, having about one tenth the stimulating effect of either.
Theobromine is found in cocoa products, tea (only in very small amounts) and kola nuts, but is not found in coffee. In cocoa, its concentration is generally about 7 times as great as caffeine. Although, caffeine is relatively scarce in cocoa, its mainly because of theobromine that cocoa is stimulating.
Theophylline is found in very small amounts in tea, but has a stronger effect on the heart and breathing than caffeine. It often the drug of choice in treating asthma bronchitis and emphysema. The theophylline found in medicine is made from extracts from coffee or tea.
4. How does caffeine taste?
Caffeine is very bitter. Barq's Root Beer contains caffeine and the company says that it has 12.78mg per 6oz and that they add it as a flavouring agent for the sharp bitterness.
5. How much theobromine/theophylline there is in ...?
Sources: Physicians Desk Reference and Institute of Food Technologies from Pafai and Jankiewicz (1991) DRUGS AND HUMAN BEHAVIOUR
cocoa 250mg theobromine
bittersweet choc. bar 130mg theobromine
5 oz cup brewed coffee no theobromine
5oz cup of tea 3-4 mg theophylline
Diet Coke none of either
B. Caffeine And Your Health
Important: This information was excerpted from several sources, no claims are made to its accuracy. The FAQ maintainer is not a medical doctor and cannot vouch for the accuracy of this information.
1. What happens when you overdose?
From Desk Reference to the Diagnostic Criteria from DSM-3-R (American Psychiatric Association, 1987):
Caffeine-Induced Organic Mental Disorder 305.90 Caffeine Intoxication
1. Recent consumption of caffeine, usually in excess of 250 mg.
2. At least five of the following signs:
1. restlessness
2. nervousness
3. excitement
4. insomnia
5. flushed face
6. diuresis
7. gastrointestinal disturbance
8. muscle twitching
9. rambling flow of thought and speech
10. tachycardia or cardiac arrhythmia
11. periods of inexhaustibility
12. psychomotor agitation
3. Not due to any physical or other mental disorder, such as an Anxiety Disorder.
Basically, overdosing on caffeine will probably be very unpleasant but not kill or deliver permanent damage. However, People do die from it.
Summarized from the Manual:
Toxic dose
The reported lethal dose is 10 grams, although one case documents survival after ingesting 24 grams. In small children ingestion of 35 mg/kg can lead to moderate toxicity. The amount of caffeine in an average cup of coffee is 50 - 200 mg. Infants metabolize caffeine very slowly.
Symptoms
--- Acute caffeine poisoning gives Early symptoms of anorexia, tremor, and restlessness. Followed by nausea, vomiting, tachycardia, and Confusion. Serious intoxication may cause delirium, seizures, supraventricular and ventricular tachyarrhythmias, hypokalemia, and hyperglycemia.
--- Chronic high-dose caffeine intake can lead to nervousness, irritability, anxiety, tremulousness, muscle twitching, insomnia, palpitations and hyperreflexia. For blood testing, cross-reaction with theophylline assays will detect toxic amounts. (Method IA) Blood concentration of 1-10 mg/L is normal in coffee drinkers, while 80 mg/L has been associated with death.
Treatment - Emergency Measures
--- Maintain the airway and assist ventilation. (See Appendix A)
--- Treat seizures and hypotension if they occur.
--- Hypokalemia usually goes away by itself.
--- Monitor Vital Signs.
--- Specific drugs and antidotes. Beta blockers effectively reverse cardiotoxic effects mediated by excessive beta-adrenergic stimulation. Treat hypotension or tachyarrhythmias with intravenous propanolol, .01 - .02 mg/kg. , or esmolol, .05 mg/kg , carefully titrated with low doses. Esmolol is preferred because of its short half life and low cardioselectivity.
Decontamination
--- Induce vomiting or perform gastric lavage.
--- Administer activated charcoal and cathartic.
--- Gut emptying is probably not needed if 1 2 are performed promptly.
Appendix A - Performing airway assistance.
1. If no neck injury is suspected, place in the Sniffing position by tilting the head back and extending the front of the neck.
2. Apply the Jaw Thrust to move the tongue out of the way without flexing the neck: Place fingers form both under the back of the jaw and thrust the jaw forward so that the chin sticks out. This should also hurt the patient, allowing you to judge depth of coma. :)
3. Tilt the head to the side to allow vomit and snot to drain out.
The toxic dose is going to vary from person to person, depending primarily on built-up tolerance. A couple people report swallowing 10 to 13 vivarin and ending up in the hospital with their stomaches pumped, while a few say they've taken that many and barely stayed awake.
A symptom lacking in the clinical manual but reported by at least two people on the net is a loss of motor ability: inability to move, speak, or even blink. The experience is consistently described as very unpleasant and not fun at all, even by those very familiar with caffeine nausea and headaches.
2. Studies on the side-effects of caffeine.
OAKLAND, California (UPI) -- Coffee may be good for life. A major study has found fewer suicides among coffee drinkers than those who abstained from the hot black brew.
The study of nearly 130,000 Northern California residents and the records of 4,500 who have died looked at the effects of coffee and tea on mortality.
Cardiologist Arthur Klatsky said of the surprising results, This is not a fluke finding because our study was very large, involved a multiracial population, men, women, and examined closely numerous factors related to mortality such as alcohol consumption and smoking.
The unique survey also found no link between coffee consumption and death risk. And it confirmed a weak connection of coffee or tea to heart attack risk -- but not to other cardiovascular conditions such as stroke.
The study was conducted by the health maintenance organization Kaiser Permanente and was reported Wednesday in the Annals of Epidemiology.
3. Caffeine and your metabolism.
Caffeine increases the level of circulating fatty acids. This has been shown to increase the oxidation of these fuels, hence enhancing fat oxidation. Caffeine has been used for years by runners and endurance people to enhance fatty acid metabolism. It's particularly effective in those who are not habitual users.
Caffeine is not an appetite suppressant. It does effect metabolism, though it is a good question whether its use truly makes any difference during a diet. The questionable rationale for its original inclusion in diet pills was to make a poor man's amphetamine-like preparation from the non-stimulant sympathomimetic phenylpropanolamine and the stimulant caffeine. (That you end up with something very non-amphetamine like is neither here nor there.)
The combination drugs were called Dexatrim (as in Dexedrine) for a reason, namely, to assert its similarity in the minds of prospective buyers. However, caffeine has not been in OTC diet pills for many years per order of the FDA, which stated that there was no evidence of efficacy for such a combination.
From Goodman and Gilman's The Pharmacological Basis of Therapeutics:
Caffeine in combination with an analgesic, such as aspirin, is widely used in the treatment of ordinary types of headache. There are few data to substantiate its efficacy for this purpose. Caffeine is also used in combination with an ergot alkaloid in the treatment of migraine (Chapter 39).
Ergotamine is usually administered orally (in combination with caffeine) or sublingually [...] If a patient cannot tolerate ergotamine orally, rectal administration of a mixture of caffeine and ergotamine tartarate may be attempted.
The bioavailability [of ergotamine] after sublingual administration is also poor and is often inadequate for therapeutic purposes [...] the concurrent administration of caffeine (50-100 mg per mg of ergotamine) improves both the rate and extent of absorption [...] However, there is little correspondence between the concentration of ergotamine in plasma and the intensity or duration of therapeutic or toxic effects.
Caffeine enhances the action of the ergot alkaloids in the treatment of migraine, a discovery that must be credited to the sufferers from the disease who observed that strong coffee gave symptomatic relief, especially when combined with the ergot alkaloids. As mentioned, caffeine increases the oral and rectal absorption of ergotamine, and it is widely believed that this accounts for its enhancement of therapeutic effects.
Finally, I'll add that adding small frogs to your coffee enhances absorption of several psychogenic tannins, a useful technique for studying temporary insanity.
I have some doubts about explanation of the mechanism(s) of the stimulatory effects of methylxanthines, like theophylline and caffeine. Inhibition of phosphodiesterase is certainly of little importance, since the concentrations of caffeine or theophylline capable of producing this effect are only rarely achieved in usual situations, including clinical ones.
Nowadays most of researchers believe that the stimulatory actions are attributable to the antagonism of the adenosine. They agree, agonists at the adenosine receptors produce sedation while antagonists at these sites, like caffeine and theophylline induce stimulation, and what is even more important, the latter substance also reverse agonists-induced symptoms of sedation, thus indicating that this effects go through these receptors.
Another possibility, however, is that methylxanthines enhance release of excitatory aminoacids, like glutamate and aspartate, which are the main stimulatory neurotransmitters in the brain.
As to the side effects: methylxanthines inhibit protective activity of common anti-epileptic drugs in animals in doses comparable to those used in humans when correction to the surface area is made. It should be underlined, that although tolerance develop to the stimulatory effects of theo or caffeine when administered on a chronic base, we found no tolerance to the above effects .
This hazardous influence was even enhanced over time. Therefore, it should be emphasized that individuals suffering from epilepsy should avoid, or at least reduce consumption of coffee and other caffeine-containing beverages.
C. How To Brew The Ultimate Caffeine Drink?
1. What is the best temperature for drip coffee?
According to chemical studies, the optimal water temperature for drip coffee is 95-98C. According to my notes, colder water doesn't extract enough caffeine/essential oils from the beans, and above such temperature the acidity increases wildly.
2. Quality of coffee
The quality of a brew depend on the following factors (in no particular order):
1. Time since grinding the beans.
2. Time since roasting.
3. Cleanliness with brewing equipment.
4. Bean quality (what crop etc).
5. Water quality.
Fact: Unless you are buying some major debris, bean quality is not very important.
Fact: The prepackaged stuff you buy in supermarkets is major debris, (in general).
Many times inferior beans are due to (a) adultered beans, either with the skin of the coffee bean or with peanut derivatives, (b) old grounds and roast.
3. Why you should never use percolators.
Percolators violate most of the natural laws about brewing coffee.
Don't over extract the oils and flavour. Percolators work by taking coffee and reheating it and throwing it over the grounds over and over and over again.
Never reheat/boil coffee. This destroys the flavour. For best flavour, boil the water, pass it over the grounds and retain the heat. Don't reheat it.
Violating these rules may not sound like much, but these are about the only rules there are. The effect of a percolator is to keep passing boiling water/coffee over the grounds until there is no flavour left and the flavour in the coffee is so dead that it's a worthless waste.
D. Peripherals And Secondary Storage
1. Proper care of coffee makers...
It is very important that you wash your coffee maker pot and filter container thoroughly at least once a week. Bitter oils stick to the glass container and plastic filter holder.
I used to wash the plastic filter container and rinse the glass pot. Coffee started to taste bad. When I was told to wash both thoroughly with plenty of soap the flavour improved instantly. Note: To the naked eye rinsed and soap washed pots look the same (clean that is).
Some drip coffee makers require periodic cleansing with a solution of water and vinegar.
If you have a coffee/teapot, the inside of which is stained with oily brown residues - also plastic/metal coffee filters, tea strainers, and stainless steel sinks in caffeine-o-phile houses - they can be restored to a shining, brand-spanking-new state by washing in hot detergent.
Get a large plastic jug, add 2..3 heaped tablespoons of Daz Automatic or Bold or whatever, and about a pint of hot water - just off the boil is the best.
Swill the jug around until the detergent is dissolved, and then pour into tea/coffeepot, and let it stand for 5 minutes, swilling the pot around occasionally, just to keep the detergent moving. Put the lid on and shake it a few times (care: slippery + hot)
Repeat as necessary. Keep it hot with a little boiling water if needed. If you have a cafeteriere, dissemble it, and soak the parts in the mixture for a few minutes, agitating occasionally.
In both cases, the residue just falls off with almost no scrubbing. It does great things with over-used filter machine filters, too.
Important: Rinse off all detergent afterwards, use lots of fresh water.
2. How to store coffee?
One should always store coffee beans in a glass, air tight container. Air is coffee's principle enemy. Glass is best because it doesn't retain the odors of the beans or the oils, which could contaminate future beans stored in the same container.
For consumption within:
1 week - room temperature is fine
2 weeks to a month - refrigerate freeze them
This prevents the chemical reactions that produce stale beans and lifeless coffee.
Caffeine F.A.Q. Continued
Books Coffee Basics:
A Quick and Easy Guide
Handy reference with hundreds of industry truths and trade secrets. Information about coffee buying, brewing, and tasting.
You will learn about
- Basic coffee facts (origin, history, varieties)
- Methods for selecting, roasting, blending, flavoring
- Decaffeinated, organic, and espresso beans
- Specialty coffee recipes
- Lists of sources for beans and equipment
Coffee Basics Home Coffee Roasting:
Romance & Revival
If you want to learn how to roast coffee at home and a bit more, this is the book for you. It provides an in depth look at the evolution of roasting methods as well as the bean itself.
The recommended roasting methods and instructions are easy to understand and follow. Filled with sample charts, journals, and definitions. A how to manual written to guide the way to roasting your own coffee.
Home Coffee Roasting The Coffee Book:
Anatomy of an Industry
from Crop to the Last Drop
A fascinating, easy to read book about the history, social implications, and economics of coffee. Many facts, figures, cartoons, and commentary.
The book explores coffee from its first use to the 1990s. Includes info about the process of cultivation, harvesting, and roasting from bean to cup, the business of coffee, and the social history of caffeine.
The Coffee Book The World of Caffeine:
The Science and Culture
of the World's Most Popular Drug
The book provides a cultural and social history of caffeine. It examines the science and health facts surrounding caffeine and how caffeine spread around the world. The historical and social backgrounds are fascinating.
If you are only going to get one book about coffee or caffeine, consider this book. It is over 300 pages, includes photographs, cartoons, charts and graphs.
The World of Caffeine Uncommon Grounds:
The History of Coffee
and How It Transformed Our World
A huge book (over 500 pages) of everything coffee. Follow the history of coffee from its beginnings in Africa, to the worldwide business that coffee has become, to the social and environmental ramifications of coffee.
The book was written by a business writer. While being interesting and fairly easy to follow, it contains a lot of information about the business side of coffee. Some readers might find this and the large size of the book a little boring in parts, but most people will love it.
Uncommon Grounds
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