Theobromine belongs to a class of alkaloid molecules known as methylxanthines. Methylxanthines naturally occur in as many as sixty different plant species and include caffeine (the primary methlyxanthine in coffee) and theophylline (the primary methylxanthine in tea). Theobromine is the primary methylxanthine found in products of the cocoa tree, theobroma cacao
Theobromine affects humans similarly to caffeine, but on a much smaller scale. Theobromine is mildly diuretic (increases urine production), is a mild stimulant, and relaxes the smooth muscles of the bronchi in the lungs. In the human body, theobromine levels are halved between 6-10 hours after consumption.
Why Chocolate Makes Us Feel Good
Several more obscure chocolate ingredients seem to act by affecting the brain’s own neurotransmitter network.
Neurotransmitters are the chemical messengers of the brain. They work by transporting electrical signals between nerve cells. These signals cause changes in the sensations and emotions that we experience.
Chocolate contains a natural ‘love drug’. Tryptophan is a chemical that the brain uses to make a neurotransmitter called serotonin. High levels of serotonin can produce feelings of elation, even ecstasy – hence the name of the designer drug that also works by increasing serotonin levels.
While tryptophan could be considered ‘chocolate’s ecstasy’, another chemical called phenylethylamine has earned the nickname ‘chocolate amphetamine.’ High levels of this neurotransmitter help promote feelings of attraction, excitement, giddiness and apprehension. Phenylethylamine works by stimulating the brain’s pleasure centres and reaches peak levels during orgasm.
But many scientists are sceptical that chocolate could produce mood-altering effects in this way. Chemicals like tryptophan and phenylethylamine, which are also found in many other foodstuffs, are present in chocolate only in very small quantities.
The same is true of anandamide, the current favourite candidate for a psychoactive chocolate ingredient. Anandamide is a neurotransmitter that targets the same brain structures as THC, the active ingredient in cannabis. But to make a substantial impact on the brain’s own natural anandamide levels, experts estimate you would need to eat several kilos of chocolate!
Neuroscientist Daniele Piomelli suggests that chocolate works more indirectly to produce its ‘high’. As well as anandamide itself, chocolate contains two chemicals known to slow the breakdown of anandamide. Chocolate might therefore work by prolonging the action of this natural stimulant in the brain.