By ABC Science Online Alex Wilde
Chocoholics can happily eat chocolate for pleasure but for those who are stressed and clinically depressed, the high is short-lived and chocolate may even deepen the downer, a review shows.
The findings, which will be published in the Journal of Affective Disorders, fly in the face of the myth that chocolate is an antidepressant.
The analysis, which is the most comprehensive literature review on how chocolate affects mood, shows that the motivation behind eating chocolate determines which neurotransmitters are activated, and hence your mood.
The review’s Australian authors, from the Black Dog Institute at the Prince of Wales Hospital in Sydney, identified two groups of chocolate eaters based on motivation.
They are cravers, who eat chocolate as an indulgent pleasure, and emotional eaters, who use chocolate in a bid to alleviate depression.
Professor Gordon Parker, the executive director of the Black Dog Institute and lead author, says cravers see chocolate like a good glass of wine, and anticipating and eating the treat releases ‘feel good’ neurotransmitters.
“Chocolate craving as an indulgent pleasure seems to stimulate the dopamine system in the brain, and provides an enjoyable experience,” he said.
“But the emotional eaters, people who eat chocolate to relieve boredom, stress or clinical depression, are looking for an opioid effect to improve their mood.”
He says for them, at best chocolate only provides temporary relief.
But this is quickly followed by a return to or a worsening of their earlier negative state.
Consuming sweet foods is thought to release the neurotransmitter beta-endorphin in the hypothalamus, which is said to have an opiate effect on the body.
But why the chocolate high is so transient and insufficient to sustain mood in those who eat it for emotional reasons remains unknown.
The theory that chocolate acts as an antidepressant comes from the common belief that a serotonin deficiency causes chocolate cravings, but the review has found no support for this hypothesis.
“It is true that chocolate acts on the same neurological system as serotonin,” Professor Parker said.
“But you’d have to eat a truck load of chocolate before you have had the equivalent of one antidepressant tablet.
“Our review rejects any possibility that chocolate desired as a way of relieving stress or when feeling down has any antidepressant benefit.”
The review says stimulants such as caffeine, theobromine, tyramine and phenylethylamine, are also present in concentrations too low to have any significant psychoactive effect.