Definition Caffeine occurs naturally in foods and beverages. It is known to be a potent stimulant of the central nervous system (CNS).
Coffee - Brewed (200ml) = 70-175 mg Caffeine
Coffee - Instant (200ml) = 50-100 mg Caffeine
Coffee - Decaffeinated (200ml) = 2-4 mg Caffeine
Tea (200ml) = 60-90 mg Caffeine
Iced Tea (200ml) = 55mg Caffeine
Hot chocolate drinks (250ml) = 10-50 mg Caffeine
Soft Drink (360ml):
Pepsi = 40 mg Caffeine
Diet Pepsi = 35 mg Caffeine
Coke = 45 mg Caffeine
Diet Coke = 45 mg Caffeine
Dr Pepper = 40 mg Caffeine
Mountain Dew = 50 mg Caffeine
"Energy" drinks = 50-120 mg Caffeine
Milk Drinks (500 ml):
Ice Break = 22 mg Caffeine
Rush = 13 mg Caffeine
Breaka (regular) = 13 mg Caffeine
Breaka (lite) = 11 mg Caffeine
How does the nutrient affect the body?
Caffeine acts as a central nervous system stimulant
Information Caffeine is known in chemical terms as "trimethylxanthine." High levels of it occur naturally in cocoa and coffee beans. Trimethylxanthine is added to caffeinated soft drinks during processing. Caffeine is also added to several over-the-counter medications to increase their effects.
The caffeine content of coffee depends on the type of coffee bean. Beans from the plant species robusta generally have more caffeine than those from the arabica species. Arabica beans generally produce a more full-bodied flavour. These beans are the ones likely to be found in gourmet coffee shops. The roasting and brewing of coffee also play a part. Contrary to popular belief, darker roasted beans actually have less caffeine. The heat literally roasts out the caffeine.
Caffeine is one of the most thoroughly studied food constituents. Studies have failed to show a link between caffeine and such chronic diseases as heart disease and cancer. The most well defined effect of caffeine is as a central nervous system stimulant. Caffeine levels peak in the bloodstream within 30 to 60 minutes of consuming it. The result is increased alertness and heightened concentration.
Some people tolerate this boost well. Others become over stimulated. Side effects of too much coffee include insomnia, anxiety, irritability and diarrhoea. People with any of these symptoms should limit their caffeine intake to less than 200 to 300 milligrams per day.
Some research does suggest a link between caffeine and birth defects and miscarriages. Pregnant women and those who might become pregnant are advised to limit their caffeine intake or eliminate caffeine. The warning was based on research on rats. In this study, pregnant rats were fed amounts of coffee equal to dozens of cups daily. Many of the baby rats were born with missing toes. However, later studies that used more natural levels of caffeine found no problems with birth defects. No other well controlled studies have linked caffeine to birth defects in humans.
In 1993, two studies were published in The Journal of the American Medical Association concerning caffeine intake and miscarriages. The first study found that consuming moderate amounts of caffeine during pregnancy did not increase the risk of miscarriage. The second study showed that the chance of miscarriage jumped more the 20% for each 100 mgs of caffeine a pregnant woman took in each day.
Health risks of taking caffeine during pregnancy:
There may be an association between lower birth-weight and drinking in excess of five cups of coffee or tea, or six cans of cola drinks in a day.
Irregular foetal heart rate may be associated with excessive amounts of caffeine intake late in pregnancy
Neonatal Abstinence Syndrome has been observed in babies whose mothers used excessive amounts of caffeine.
The bottom line: pregnant women or those wishing to become pregnant should talk to their doctor about the effects of caffeine. People with high blood pressure or an irregular heartbeat should also talk to their doctor about caffeine, since it can negatively affect both conditions.
Author: Reviewer: eknowhow Medical Review Panel Editor: Dr John Hearne Last Updated: 7/02/2005 Contributors Potential conflict of interest information for reviewers available on request
