Duni Ernald, Zambianchi Alessandro
Chocolate contains many pharmacologic agents, any or all of which may evoke physiological or psychological sensations and may be the driving force behind chocolate cravings. In the past several years, the psychopharmacologic effects of chocolate have been a topic of increasing interest among nutrition neuroscientists as evidence continues to build for the localization of chocolate's actions and the precise biomolecules involved.
• Biogenic Amines
Several endogenous biogenic amines are found in chocolate, most notably, tyramine and phenylethylamine (PEA). PEA is produced by brain tissue and is rapidly metabolized by monoamine oxidase-β (MAO- β) and aldehyde dehydrogenase to phenylacetic acid, the major metabolite of PEA in the brain. Studies have demonstrated that PEA is pharmacologically active and that it is stimulatory when administered.
Another group of compounds present in chocolate are the alkaloid methylxanthines, caffeine (1,3,7-trimethylxanthine) and theobromine (3,7-dimethylxanthine), both cause noticeable behavioral effects. They are absorbed from the stomach and intestines and easily crossing both the blood-brain and placental barriers. In the brain, the methylxanthines compete with adenosine, a presynaptic inhibitory neuromodulator, and block its receptor, thereby eliminating its inhibitory action and causing arousal.
Some persons may use chocolate as a form of self-medication to compensate for insufficient food intake or specific nutrient deficiencies. Magnesium deficiency results in selective depletion of CNS levels of dopamine. Therefore, it is possible that stress-induced magnesium deficiency contributes to the increase in chocolate cravings. Nuts contain comparable amounts of this nutrient, however, and should be craved in a similar way.
Alternatively, chocolate consumption may be a behavioral mechanism for homeostatic regulation of certain neurotransmitters involved in the regulation of hunger, mood, and/or addictive behaviors. Low CNS levels of serotonin have been associated with depression and ingestion of chocolate, has been purported to increase tryptophan uptake and serotonin production by the brain. A typical chocolate bar contains an amount of protein that may be sufficient to block a rise in serum level of tryptophan and the resultant increase in CNS levels of serotonin.
Cannabinoid-like Fatty Acids: (and )
Chocolate and cocoa are thought to contain the unsaturated N-acylethanolamines (N-oleoylethanolamine, N-linoleoylethanolamine), which are chemically and pharmacologically related to anandamide. These lipids could mimic cannabinoid ligands. Elevated brain anandamide levels could magnify the sensory properties of chocolate that are fundamental to craving.
Alternatively, the consumption of chocolate may be a homeostatic mechanism for regulation of behavior of some neurotransmitters involved in regulating appetite, hunger, mood, and addictive behavior. Several studies have found that negative moods are especially important between cravers and have an upward trend "emotional eating".