 |
What are caffeine's effects within the body?
Caffeine's effects can be felt quickly making this widely used drug a perfect wake-me-up-in-the-morning kick-start. Even before its discovery in 1819[1], coffee and chocolate have been prized and consumed for its stimulant properties.
Caffeine is a chemical compound, made up of four chemical elements, carbon (C), nitrogren (N), oxygen(O) and hydrogen (H). In its pure form, at room temperature, it is odorless and looks like cornstarch.[2] It is known in chemical terms as trimethylxanthine. Caffeine Metabolism Caffeine is a fat soluble substance that passes very quickly into almost every cell in the body soon after ingestion. It also easily passes over the blood brain barrier (the body's defensive mechanism protecting the central nervous system from biological attack). Once caffeine has been ingested it will make its way to the liver where it is metabolized and converted into similar but different substances (known as metabolites). The primary by-products or metabolites of caffeine metabolism are paraxanthine (accounts for 70 - 80% of the converted caffeine), theophylline and theobromine.[3] These substances are achieved by taking away one or more of caffeine's methyl groups (carbon and hydrogen groups, CH3). When the last methyl group has been stripped away, xanthine is left and this is eliminated in urine or re-used.[4]
Caffeine Effects - How Does Caffeine React In The Body?Caffeine's effects are widespread and include stimulation of the central nervous system, increases in urine production and gastric secretions, increases in heart rate and relaxation of smooth muscle.[5]
The way in which the stimulatory caffeine effects are produced, is still not wholly known, however, the most widely accepted theory is that it blocks a chemical called adenosine from binding with its site receptors.
When adenosine binds with its receptors, it is known to cause a decrease in heart rate, induce low blood pressure and induces sleep. Adenosine and adenosine analogues also are known to inhibit lipolysis. The effects of caffeine may be explained, at least in part, by caffeine binding with these same adenosine receptors (preventing adenosine from binding with them). The result of caffeine's effects are increasing heart rate and respiration amongst other affects. The act of caffeine binding with adenosine receptors may also have a knock-on effect and stimulate the release of other substances into the body's blood stream. These substances may also add to the stimulatory caffeine effects. Is Caffeine linked to weight loss?The role of caffeine in weight loss center around four major theories. These theories say that:
I decided to look at the above theories and whether they have bearing on the role of caffeine in weight loss. So I have done some digging and have presented research both supporting and opposing the theories at the Caffeine and Lipolysis page and on Caffeine and Insulin Levels.
Sources:[1] Weinberg, B.A., Bealer, B.K., (2002) The World of Caffeine: The Science and Culture of The Worlds Most Popular Drug Routledge, Prolouge [2] Weinberg, B.A., Bealer, B.K., (2002) The World of Caffeine: The Science and Culture of The Worlds Most Popular Drug Routledge, P. 216 [3] Weinberg, B.A., Bealer, B.K., (2002) The World of Caffeine: The Science and Culture of The Worlds Most Popular Drug Routledge, P. 219 - 221 [4] Braun, S., (1996) Buzz: The Science and Lore of Alcohol and Caffeine Oxford University Press, P. 119 - 120 [5] Paluska, Scott. (MD) Caffeine and Exercise Diet & Fitness TipsIf you found this useful, get great diet recipes, fat burning exercises and other articles like this article on cereals in our diet & fitness newsletter.
|
