An extensive study showed that beer should make you happy
For some people, a beer is not just an alcoholic thirst quencher, but also a balance to day and relaxation. Scientists at the University of Erlangen-Nuremberg have now found that this is not an imagination. They examined 13,000 food ingredients to find out which substances activate the reward system in the brain. A clear winner was Hordenin, an ingredient in barley malt and beer.
There are foods that make you happy. Well, maybe not happy, but happy. And that's why you don't stop eating them - even when you're already full. This phenomenon is called hedonic food intake in technical jargon. The good feeling is triggered by the neurotransmitter dopamine: tempting foods activate brain areas of the reward center where the dopamine D2 receptor can be found. Scientists from the Henriette Schmidt-Burkhardt Chair for Food Chemistry at the FAU have now asked themselves: Are there special ingredients in foods that - like the body's own dopamine - activate the dopamine D2 receptor?
To find out, the researchers, together with colleagues from the Computer Chemistry Center at FAU, used the virtual screening method, an approach known from pharmaceutical research. The food ingredients are not first examined in the laboratory, but on the computer. The advantage: In contrast to classic screening methods, in which only a small selection of food extracts can be tested in the laboratory, the researchers can examine all possible existing ingredients.
13,000 molecules, 17 hits
The scientists first created a virtual database of 13,000 molecules found in food. The aim of this database was to find the molecules that fit the dopamine D2 receptor - the key for the keyhole, so to speak. The computer calculated which molecules are likely to interact with the dopamine D2 receptor: either via synthetic substances that are already known to interact with the receptor - such as drugs for the treatment of Parkinson's or schizophrenia - or via the three-dimensional structure of the Receptor. In the end, 17 of the 13,000 options remained, which were then tested in the laboratory in cooperation with the Chair of Pharmaceutical Chemistry at FAU.
Surprise find beer
The most promising test results showed the substance hordenine, an ingredient of barley malt and beer. "It is surprising that - without having specifically searched for the group of luxury foods - an ingredient in beer leads to the activation of the dopamine D2 receptor," says Prof. Dr. Monika Pischetsrieder.
Just like dopamine, hordenine activates the dopamine D2 receptor - with one important difference: it works via a different signaling pathway. In contrast to dopamine, hordenine activates the receptor exclusively via so-called G proteins, which could lead to a more lasting effect on the reward center. The researchers are currently investigating whether the amounts contained in beer are sufficient to have a noticeable impact on the reward center. Overall, however, the results suggest that hordenine could contribute to the mood-enhancing effect of beer. (sb, pm)
The scientists have published their results in Scientific Reports: Sommer, Thomas; Huebner, Harald; El Kerdawy, Ahmed; Gmeiner, Peter; Pischetsrieder, Monika; Clark, Tim. Identification of the Beer Component Hordenine as Food-Derived Dopamine D2 Receptor Agonist by Virtual Screening a 3D Compound Database. Scientific Reports (2017), 7: 44201, DOI: 10.1038 / srep44201.