Caffeine and your Health FAQ

How to cut caffeine intake?

Most people report a very good success ratio by cutting down caffeine intake at the rate of 1/2 cup of coffee a day. This is known as Caffeine Fading. Alternatively you might try reducing coffee intake in discrete steps of two-five cups of coffee less per week (depending on how high is your initial intake). If you are drinking more than 10 cups of coffee a day, you should seriously consider cutting down.

The best way to proceed is to consume caffeine regularly for a week, while keeping a precise log of the times and amounts of caffeine intake (remember that chocolate, tea, soda beverages and many headache pills contain caffeine as well as coffee). At the end of the week proceed to reduce your coffee intake at the rate recommended above. Remember to have substitutes available for drinking: if you are not going to have a hot cup of coffee at your 10 minute break, you might consider having hot chocolate or herbal tea, but NOT decaff, since decaff has also been shown to be addictive. This should take you through the works without much problem.

Some other people quit cold turkey. Withdrawal symptoms are quite nasty this way (see section below) but they can usually be countered with lots of sleep and exercise. Many people report being able to stop drinking caffeine almost cold-turkey while on holidays on the beach. If quitting cold turkey is proving too hard even in the beach, drinking a coke might help.

What are the symptoms of caffeine withdrawal?

Regular caffeine consumption reduces sensitivity to caffeine. When caffeine intake is reduced, the body becomes oversensitive to adenosine. In response to this oversensitiveness, blood pressure drops dramatically, causing an excess of blood in the head (though not necessarily on the brain), leading to a headache.

This headache, well known among coffee drinkers, usually lasts from one to five days, and can be alleviated with analgesics such as aspirin. It is also alleviated with caffeine intake (in fact several analgesics contain caffeine dosages).

Often, people who are reducing caffeine intake report being irritable, unable to work, nervous, restless, and feeling sleepy, as well as having a headache. In extreme cases, nausea and vomiting has also been reported.

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:

• restlessness
• nervousness
• excitement
• insomnia
• flushed face
• diuresis
• gastrointestinal disturbance
• muscle twitching
• rambling flow of thought and speech
• tachycardia or cardiac arrhythmia
• periods of inexhaustibility
• 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 very unpleasant but not kill or deliver permanent damage. However, People do die from it.

Toxic dose

The LD_50 of caffeine (that is the lethal dosage reported to kill 50% of the population) is estimated at 10 grams for oral administration. As it is usually the case, lethal dosage varies from individual to individual according to weight. Ingestion of 150mg/kg of caffeine seems to be the LD_50 for all people. That is, people weighting 50 kilos have an LD_50 of approx. 7.5 grams, people weighting 80 kilos have an LD_50 of about 12 grams.

In cups of coffee the LD_50 varies from 50 to 200 cups of coffee or about 50 vivarins (200mg each).

One exceptional case documents survival after ingesting 24 grams. The minimum lethal dose ever reported was 3.2 grams intravenously, this does not represent the oral MLD (minimum lethal dose).

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 & hypotension if they occur.
• Hypokalemia usually goes away by itself.
• Monitor Vital Signs.
• Specific drugs & 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.

What are the Effects of caffeine on pregnant women.

Caffeine has long been suspect of causing mal-formations in fetus, and that it may reduce fertility rates.

These reports have proved controversial. What is known is that caffeine does causes malformations in rats, when ingested at rates comparable to 70 cups a day for humans. Many other species respond equally to such large amounts of caffeine.

Data is scant, as experimentation on humans is not feasible. In any case moderation in caffeine ingestion seems to be a prudent course for pregnant women. Recent references are Pastore and Savitz, Case-control study of caffeinated beverages and preterm delivery. American Journal of Epidemiology, Jan 1995.

Does Caffeine effect male fertility?

On men, it has been shown that caffeine reduces rates of sperm motility which may account for some findings of reduced fertility.

What is the relationship between Caffeine and Osteoporosis (Calcium loss)?

From the Journal of AMA: (JAMA, 26 Jan. 1994, p. 280-3.)

"There was a significant association between (drinking more) caffeinated coffee and decreasing bone mineral density at both the hip and the spine, independent of age, obesity, years since menopause, and the use of tobacco, estrogen, alcohol, thiazides, and calcium supplements [in women]."

Except when:

"Bone density did not vary [...] in women who reported drinking at least one glass of milk per day during most of their adult lives."

That is, if you drink a glass of milk a day, there is no need to worry about the caffeine related loss of calcium.

How does Caffeine affect 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 affect 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" or Dexa-whosis (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 migrane (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 migrane, 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.

Nowadays most of researchers believe that the stimulatory actions are attributable to the antagonism of the adenosine. 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 antiepileptic drugs in exptl. 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.