Cacao, derived from the seeds of the Theobroma cacao tree, is consumed as cocoa powder and dark chocolate. The experience of consuming high-cacao products suggests a gentle, prolonged stimulant effect. This raises the question of how cacao differs from common sources like coffee. The answer lies in the unique blend of psychoactive compounds naturally present in the cacao bean.
The Primary Psychoactive Component Theobromine
The most abundant methylxanthine compound in cacao is theobromine, a close chemical relative of caffeine. Theobromine is a central nervous system (CNS) stimulant, though it is less potent than caffeine. Its effects are distinct, offering a milder and longer-lasting form of stimulation compared to the sharp peak and rapid decline associated with coffee.
The primary mechanism of action for theobromine is acting as an antagonist to adenosine receptors in the brain. Adenosine promotes relaxation and drowsiness; by blocking these receptors, theobromine promotes wakefulness and alertness. Theobromine is also a vasodilator, widening blood vessels, which improves blood flow and stimulates the heart.
Theobromine is metabolized more slowly by the liver than caffeine, contributing to its sustained effects. While caffeine typically peaks in the bloodstream within 30 to 40 minutes and has a half-life of 2.5 to 5 hours, theobromine is fat-soluble and takes 2 to 3 hours to reach peak concentration. Its half-life is significantly longer (6 to 12 hours), providing a gentler energetic feeling without the sudden “crash.” Theobromine also inhibits phosphodiesterase enzymes, contributing to increased cardiac output and metabolic effects.
Secondary Stimulants and Neuromodulatory Effects
While theobromine is the dominant methylxanthine, cacao contains other compounds that contribute to its psychoactive profile. Caffeine is present, but in significantly lower concentrations than theobromine (ranging from 2.5:1 to 23:1 parts theobromine to caffeine). This lower level of caffeine works synergistically with theobromine, adding to the overall stimulating effect.
Other minor compounds contribute to cacao’s unique mood-enhancing reputation. Phenylethylamine (PEA) is a trace amine chemically similar to amphetamines. It acts as a neuromodulator, stimulating the release of dopamine and norepinephrine, which is associated with heightened alertness.
Cacao also contains anandamide, an endocannabinoid that interacts with the same receptor system as THC. Although anandamide and PEA are frequently cited for mood-boosting properties, their true systemic impact is modest. They are present in small amounts, and scientists question how much of the compounds survive digestion to reach the brain, suggesting their contribution to the stimulant effect is minor compared to the methylxanthines.
Stimulant Concentration in Cacao Products
The level of stimulants experienced is directly proportional to the amount of cacao in the final product and how it has been processed. Raw cacao beans contain high levels; raw cocoa powder averages around 2060 milligrams of theobromine per 100 grams. Commercial milk chocolate averages much lower levels, typically around 150 milligrams per 100 grams, along with minimal caffeine.
The percentage of cacao listed on a chocolate bar is a reliable indicator of its stimulant load; a higher percentage of cacao solids means greater concentrations of both theobromine and caffeine. Dark chocolates have higher methylxanthine levels than milk chocolates. A single serving of dark chocolate may contain 140 to 230 milligrams of theobromine, while pure, minimally processed cacao may contain between 300 and 470 milligrams per serving.
Processing methods also affect the final stimulant content. The process of alkalization, sometimes called Dutching, is used to reduce the natural acidity and bitterness of cocoa powder, resulting in a darker color and milder flavor. While this process is primarily known to reduce the content of beneficial flavanols, a higher degree of alkalization may also decrease the concentration of methylxanthines, including theobromine. Therefore, natural, non-alkalized cocoa powder generally retains more of the original stimulant compounds than Dutched cocoa.