There is a persistent urban legend that Chocolate contains caffeine. It would seem that this rumor is based primarily on a confusion between two similar alkaloids: caffeine and Theobromine. Theobromine is the active ingredient in Chocolate and it occurs only in Cacao. The two stimulants are related and have a similar structures, but are very different chemicals with different properties, effects and origins. There are of course, some Chocolate products that have added caffeine, but it does not occur naturally in Chocolate.
This rumor seems to have a life of its own; it won't go away and yet most references to it are references to the urban legend itself! Amusingly, almost all of the Chocolate & caffeine references on the Internet are circular. (Follow the references through a few links sometime -- you often wind up back at the page where you began!!) It is actually quite common to see references that confuse Caffeine and Theobromine. Many people and some semi-scientific sources confuse the two. Stollwerck, for example, says in one place Chocolate contains 1.2% Theobromine and 0.2% Caffeine, but in another place it says just 1.4% Caffeine and doesn't mention Theobromine, which is obviously wrong.
There is no scientific substantiation that Chocolate contains caffeine, and a great deal of evidence that it does not. The Biochemist, (Apr/May 1993, p 15) did chemical composition tests where they specifically distinguished between Caffeine and Theobromine. They found regularly up to 1.3% by weight Theobromine in Chocolate. They also found other pharmacologically active compounds including up to 2.20% Phenylethylamine up to 1.54% Tele- methylhistamine and occasionally up to 5.82% Serotonin. They could not detect any Caffeine at all. (Full results are on the Science Page.) I have yet to see a dependable chemical reference that includes Caffeine in Chocolate. (The Merck Index, 12th Edition says that a very small amount of Caffeine is found in the hulls of of the Cacao seeds, the hulls are discarded before processing.)
People seem to assume that caffeine is the only stimulant. Theobromine clearly has stimulant properties, so people reflexively attribute those effects to caffeine -- even though many of the effects are fundamentally different from caffeine. I guess they think it is easier to just say it is caffeine. I believe that many people casually refer to caffeine, when they really mean a whole class of chemicals called xanthines, of which caffeine is but one example. This is roughly equivalent to calling apes, human, because both are primates and humans are the more familiar type primate. Both are primates, but the differences are pretty obvious.
There is a similar confusion with the Andean tea Maté. Like Chocolate, Maté clearly has stimulant properties, which are obviously very different from caffeine's effects; however many people say it contains caffeine simply because because it is a stimulant. Yerba Maté contains Mateine, a xanthine even more closely related to Caffeine than Theobromine. It is a simple stereo-isomer of caffeine. Mateine, like Theobromine, is not addictive.
The name of this chemical, Theobromine, is derived from the genus name of the Cacao tree (Theobroma cacao. You will sometimes see a reference to Theobromide, this doesn't exist - it is an incorrect reference to Theobromine.
The ine ending indicates the "free base" nature of the molecule, like caffeine. Compare theobroma & theobromine; caffea & caffeine; coca and cocaine; in each case the portion of the plant name turned into a name ending with -ine, this is for the amine funcitonality with in the molecule (the alkaloid). The Theobromide usage is probably a mistake arising from the element bromine and ion bromide. The ion bromide is common while the element bromine is not found in nature. There is no entry for Theobromide in the Merck Index, Theobromine is listed as entry 9353 on pg 1653 in the 13th edition. -Assistant Professor Robert M. Burns, Department Of Chemistry, Alma College
Effects of the two stimulants
Theobromine and caffeine are similarly constructed types of pharmacologically active chemicals metabolized by the liver. Both are stimulants but with very noticeably different effects:
In both cases, smoking cigarettes accelerates the dissipation from the system.
Theobromine is a strong stimulant and was used by the Spanish to keep their armies going while conquering Central and South America. Chocolate (real Chocolate, not candy) can keep you up at night -- especially very young children (but that doesn't mean that it is caffeine). Nursing mothers who eat pure chocolate will find their children happy and wide awake several hours later.
Chocolate does not trigger Caffeine allergies. (Caffeine causes me an almost immediate migraine, while Theobromine, i have discovered eases (but doesn't eliminate, unfortunately) my migraines.) I have found that when i have tasted portions of a pure (70% or greater Cacao) Chocolate bar that is 100% from the Crillo variety i have had immediate, sharp headaches
There are a number of serious health problems associated with caffeine, most of which have not been associated with Theobromine:
- Large quantities of Caffeine have shown decreased sperm counts in rats.
- Well controlled studies have suggested that 2% of miscarriages could be due to Caffeine in coffee.
- Dehydration headaches -- Most headaches (estimates range from 50% to 90%) are caused by dehydration, and one of the primary causes of dehydration in the USA is the large quantity of Caffeine that most people consume. (Caffeine laden drinks like CocaCola and Coffee don't quench your thirst, they actually increase it!)
- Heart trouble
There are several minor psycoactive chemicals in Chocolate as well as Theobromine: Phenylethylamine, Theophylline, Tele-methylhistamine Phenyethylamine, affects mood swings by causing an initial emotional high then a short time later an emotional low. It causes blood pressure and blood-sugar levels to rise, resulting in a feeling of alertness and contentment.
It was once thought that Tea contained large amounts of Theophylline, however it turns out that Tea contains significantly more amounts of caffeine than theophylline.