The researchers from Friedrich-Alexander-Universitat Erlangen-Nürnberg in Bavaria, Germany found that Hordenine, which is found in malted barley and beer seems to do the job quite well. The team examined 13,000 food components to find out whether they stimulate the reward center in the brain and make people feel good. Hedonic hunger is the drive to eat for pleasure rather than to satisfy an actual biological need.
‘Knocking back a beer or two won’t make you smarter, but it could boost your creativity and make you feel good.’
This feel-good effect is caused by the neurotransmitter dopamine -- tempting foods stimulate the reward centre in the brain where the dopamine D2 receptor is located. The team investigated whether there are special substances in foods that activate the dopamine D2 receptor in the same way as dopamine. The team worked with FAU's Computer Chemistry Centre using a virtual screening approach which is often used in pharmaceutical research.
This process analyses food components in a computer simulation rather than in the laboratory. Using computer simulations means that all types of known substance can be investigated. Using this database, the objective was to find those molecules that fit the dopamine D2 receptor -- rather like finding the right key for a lock. In the end, 17 of the original 13,000 options were selected and these were analysed in the laboratory in cooperation with the Division of Medicinal Chemistry at FAU.
The most promising results were obtained for hordenine, a substance present in malted barley and beer. "It came as a bit of surprise that a substance in beer activates the dopamine D2 receptor, especially as we were not specifically looking at stimulant foodstuffs," explained Dr Monika Pischetsrieder. Just like dopamine, hordenine stimulates the dopamine D2 receptor, however it uses a different signalling pathway.
In contrast with dopamine, hordenine activates the receptor solely through G proteins, potentially leading to a more prolonged effect on the reward centre of the brain.