Chocolate is a psychoactive
food. It is made from the seeds of the tropical cacao tree, Theobroma
cacao. The cacao tree was named by the 17th century Swedish naturalist,
Linnaeus. The Greek term theobroma means literally "food of the gods".
Chocolate has also been called the food of the devil; but the theological basis
of this claim is obscure.
Cacao beans were used by the
Aztecs to prepare to a hot, frothy beverage with stimulant and restorative
properties. Chocolate itself was reserved for warriors, nobility and priests.
The Aztecs esteemed its reputed ability to confer wisdom and vitality. Taken
fermented as a drink, chocolate was also used in religious ceremonies. The
sacred concoction was associated with Xochiquetzal, the goddess of fertility.
Emperor Montezuma allegedly drank 50 goblets a day. Aztec taxation was levied in
cacao beans. 100 cacao beans could buy a slave. 12 cacao beans bought the
services of courtesan.
The celebrated Italian
libertine Giacomo Casanova (1725-1798) took chocolate before bedding his
conquests. This was on account of chocolate's reputation as a subtle
aphrodisiac. More recently, a study of 8000 male Harvard graduates showed that
chocaholics lived longer than abstainers. Their longevity may be explained by
the high polyphenol levels in chocolate. Polyphenols reduce the oxidation of
low-density lipoproteins and thereby protect against heart disease. Such
theories are still speculative.
Chocolate as we know the
confectionery today dates to the inspired addition of triglyceride cocoa butter
by Rodolphe Lindt in 1879. The advantage of cocoa butter is that its addition to
chocolate sets a bar so that it will readily snap and then melt on the tongue.
Cocoa butter begins to soften at around 75 F; it melts at around 97 F.
Today, chocolates of every
description are legal, unscheduled and readily available over the counter. Some
50% of women reportedly claim to prefer chocolate to sex, though this response
may depend on the attributes of the interviewer. More than 300 different
constituent compounds in chocolate have been identified. Chocolate clearly
delivers far more than a brief sugar high. Yet its cocktail of psychochemical
effects in the central nervous system are poorly understood. So how does it
work?
Cocktail Chocolate
contains small quantities of anandamide, an endogenous cannabinoid found in the
brain. Sceptics claim one would need to consume several pounds of chocolate to
gain any very noticeable psychoactive effects; and eat a lot more to get fully
stoned. Yet it's worth noting that N-oleolethanolamine and
N-linoleoylethanolamine, two structural cousins of anandamide present in
chocolate, both inhibit the metabolism of anandamide. It has been speculated
that they promote and prolong the feeling of well-being induced by anandamide.
Chocolate contains caffeine.
But the caffeine is present only in modest quantities. It is easily obtained
from other sources.
Chocolate's theobromine
content may contribute to - but seems unlikely to determine - its subtle but
distinctive profile.
Chocolate also contains
tryptophan. Tryptophan is an essential amino acid. It is the rate-limiting step
in the production of the mood-modulating neurotransmitter serotonin. Enhanced
serotonin function typically diminishes anxiety. Yet tryptophan can normally be
obtained from other sources as well.
Like other palatable sweet
foods, consumption of chocolate triggers the release of endorphins, the body's
endogenous opiates. Enhanced endorphin-release reduces the chocolate-eater's
sensitivity to pain. Endorphins probably contribute to the warm inner glow
induced in susceptible chocaholics.
Acute monthly cravings for
chocolate amongst pre-menstrual women may be partly explained by its rich
magnesium content. Magnesium deficiency exacerbates PMT. Before menstruation,
too, levels of the hormone progesterone are high. Progesterone promotes fat
storage, preventing its use as fuel; elevated pre-menstrual levels of
progesterone may cause a periodic craving for fatty foods. One study reported
that 91% of chocolate-cravings associated with the menstrual cycle occurred
between ovulation and the start of menstruation. Chocolate cravings are admitted
by 15% of men and around 40% of women. Cravings are usually most intense in the
late afternoon and early evening.
Cacao and chocolate bars
contain a group of neuroactive alkaloids known as tetrahydro-beta-carbolines.
Tetrahydro-beta-carbolines are also found in beer, wine and liquor; they have
been linked to alcoholism. But the possible role of these chemicals in chocolate
addiction remains unclear.
Perhaps chocolate's key
ingredient is its phenylethylamine "love-chemical". Yet the role of the
"chocolate amphetamine" is disputed. Most if not all chocolate-derived
phenylethylamine is metabolised before it reaches the CNS. Some people may be
sensitive to its effects in very small quantities.
Phenylethylamine is itself a
naturally occurring trace amine in the brain. Phenylethylamine releases dopamine
in the mesolimbic pleasure-centres; it peaks during orgasm. Taken in unnaturally
high doses, phenylethylamine can produce stereotyped behaviour more prominently
even than amphetamine. Phenylethylamine has distinct binding sites but no
specific neurons. It helps mediate feelings of attraction, excitement,
giddiness, apprehension and euphoria. One of its metabolites is unusually high
in subjects with paranoid schizophrenia.
There is even a
phenylethylamine theory of depression. Monoamine oxidase type-b has been
described as phenylethylaminase; and taking an selective MAO-b inhibitor,
selegiline (l-deprenyl), can accentuate chocolate's effects. Some subjects
report that bupropion (Wellbutrin, Zyban) reduces their chocolate-cravings; but
other chocaholics dispute this. Courtesy of www.chocolate.org
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