IFIC REVIEW (Continue)

Continued from previous post:

IFIC

REVIEW

International Food Information Council Foundation

Caffeine & Health:

Clarifying The Controversies

SOURCES OF CAFFEINE

Caffeine is a naturally occurring substances found in the leaves, seeds and/of fruits of at least 63 plant species worldwide and is part of a group of compounds known as methylxanthines. The most commonly known sources of caffeine are coffee, cocoa beans, kola nuts and tea leaves. [Barone and Roberts, 1996; Frary et al., 2005]

           

The amount of caffeine in food products varies depending upon the serving size, the type of product, and preparation method. With teas and coffees, the plant variety also affects the caffeine content. An eight-ounce cup of drip-brewed coffee typically has 65-120mg caffeine; an eight-ounce serving of brewed tea has 20-90mg; and a 12-ounce canned soft drink has 30-60mg. [Knight, et al., 2004] Energy drinks can contain 50-160mg or more per eight-ounce serving, plus caffeine from guarana and other added sources not normally declared as caffeine; and one ounce of solid milk chocolate typically has just six mg caffeine (see Table 1).[American Beverage Association, 2007; Mayo Clinic, 2005]

           

Other sources of caffeine include over-the-counter pain reliever. Caffeine is an adjuvant-it increases the rate at which the medication is absorbed into the body. It is also present in some stimulant tablets and cold medications. Caffeine can be present in these products ranging from 16-200mg. [Cleveland Clinic, 2006]

TABLE 1

CAFFEINE CONTENT CHART		MILLIGRAMS OF CAFFEINE
ITEM		TYPICAL                    RANGE*
Coffee (8 oz. cup)	Brewed, drip method	85	65-120
	Instant	75	60-85
	Decaffeinated	3	2-4
	Espresso (1 oz. cup)	40	30-50
Teas (8 oz. cup)	Brewed, major U.S. brands	40	20-90
	Brewed, imported brands	60	25-110
	Instant	28	24-31
	Iced	25	9-50
Soft drinks (Cola – 12 oz. serving		40	30-60
Energy drinks (Approx 250ml. – 8.3 oz. serving		80	50-160
Cocoa beverage (8 oz. serving		6	3-32
Chocolate milk beverage (8 oz. serving)		5	2-7
Solid Milk chocolate (1 oz. serving)		6	1-15
Solid Dark chocolate, semi-sweet (1 oz. serving)		20	5-35
Baker’s chocolate (1 oz. serving)		26	26
Chocolate flavored syrup (1 oz. serving)		4	4

CAFFEINE AND COFFEE

Because caffeine is well known as an ingredient in coffee, there is much confusion, even in research literature, between the effects of caffeine and those of coffee. Coffee contains many other constituents that may also carry health benefits; however, this Review will only address the caffeine-related implications of coffee consumption.

PHYSIOLOGICAL EFFECTS

Caffeine is a pharmacologically active substance and, depending on the amount consumed, can be a mild stimulant to the central nervous system. [Mandel, 2002] Caffeine is not alone in this respect. It is one of several ingredients in foods capable of exerting pharmacological and physiological effects. For example, capsaicin in hot peppers causes the familiar burning sensation that often evokes sweating.

            When caffeine is consumed orally, it is rapidly absorbed into body fluids and distributed throughout the body in its “water phase”(i.e. blood, urine etc.). Additionally, it is recognized that caffeine readily passes through the blood-brain barrier, enabling it to exert physiological changes. [Institute of Medicine, 2001] Elimination of caffeine from the body is accomplished mainly through metabolism in the liver in a relatively short time; the average half-life, or time taken for the body to eliminate on-half of the amount consumed, is five hours. [Donovan and DeVane, 2001]

WITHDRAWAL

The American Psychiatric Association’s (APA) “Diagnostic and Statistical Manual of Mental Disorder (DSM-IV, 1994) cites no evidence for caffeine withdrawal. Some studies suggest that abruptly discontinuing consumption of caffeine can lead to mild symptoms such as headache, insomnia and anxiety, although the intensity of such symptoms varies and it is unclear whether they constitute withdrawal. [Bonnet, et al., 2005] Symptoms may be reduced by gradually decreasing caffeine intake. [Higdon and Frei, 2006] Reported symptoms are generally short-lived and relatively mild in the majority of people affected. [Nawrot, et al., 2003]

            A community-based telephone survey followed by a randomized, double-blind, controlled study on 11,169 consumers concluded that when participants were unaware of the caffeine withdrawal focus of the study, both the frequency and severity of caffeine sensitivity was much lower than previous reports. Moreover, clinically significant symptoms may be less common among the general population. [Dews, et al., 1999]

            People differ greatly in their sensitivities to caffeine, a fact also acknowledged in DSM IV. A number of factors contribute to effects of caffeine on an individual, including the amount of caffeine ingested, frequency of consumption, individual metabolism, and individual sensitivity. [Dews, 1986]

References

Barone, J.J., Roberts, H. Caffeine consumption Food Chem Toxicol. 1996; 34:119-129

Frary, C.D., Johnson, R., Wang, M.Q. Food sources and intakes of caffeine in the diets of persons in the United States. JADA. January 2005 (Vol. 105, Issues 1, Pages110-113)

Knight, C.A., Knight, I., Mitchell, D.C., and Zepp, J.E. Beverage caffeine intake in US consumers and subpopulations of interest: Estimates from the Share of Intake Panel survey. Food Chem. Toxicol. 2004 Dec; 42(12):1923-1930.

American Beverage Association (ABA) http://www.ameribev.org/all-about-beverage-products-manufacturing-marketing-consumption/americas-beverage-products/energy-drink/whats-inside/index.aspx.

Mayo Clinic, 2005 – http://www.mayoclinic.com/health/caffeine/AN01211.

Cleveland Clinic, 2006 – http://www.clevelandclinic.org/health/health-info/docs/2500/2547.asp?index=9645

Mandel, H.G. Update on caffeine consumption, disposition and action. Food Chem. Toxicol. 2002 Sep;40(9):1231-4. Review.

Institute of Medicine (IOM). Pharmacology of Caffeine in Caffeine for the Sustainment of Mental Task Performance-Formulations for Military Operations. Ch-2, Institute of Medicine. NAS, 2001.

Donovan, J.L., DeVane, C.L. A primer on caffeine pharmacology and its drug interactions in clinical psychopharmacology. Psycho-pharmacol Bull. 2001; Summer;35(3):30-48.

American Psychiatric Association (APA). Diagnostic and Statistical Manual of Mental Disorder, 4^th ed. (DSM IV). 1994, APA Press, Washington DC.

Bonnet, M.H., Balkin, T.J., Dinges, D.F., Roehrs, T., Rogers, N.L., Wesensten, N.J. The use of stimulants to modify performance during sleep loss: A review by the Sleep Deprivation and Stimulant Task Force of the American Academy of Sleep Medicine. Sleep. 2005; Sep 1;28(9):1163-1187).

Higdon, J.V., Frei, B. Coffee and health: a review of recent human research. Crit Rev Food Sci Nutr. 2006;46(2):101-123.

Nawrot, P., Jordan, S., Easwood, J., Rotstein, J., Hugenholtz, A., Feeley, M. Effects of caffeine on human health. Food Addit Contam. 2003; Jan;20(1):1-30.

Dews, P.B., Cutris G.L., Hanford, K.J. and O’Brien, C.P. The frequency of caffeine withdrawal in a population-based survey and in a controlled, blinded pilot experiment. J. Clin. Pharmacol. 1999; Dec 39:1221-1232.

Dews, P.B. Caffeine Research: An international Overview. Paper presented at a meeting of the International Life Sciences Institute (ILSI). Sydney, Australia, July 1986.

To be continued………