Scientist beer is supposed to make happy

Beer should make you happy - that was an extensive study
For some people, a beer is not just an alcoholic thirst quencher, but also a balance to the day and rest. Scientists at the University of Erlangen-Nuremberg have discovered that this is not imaginary. They studied 13,000 food ingredients to find out which substances activate the reward system in the brain. A clear winner was Hordenin, an ingredient of barley malt and beer.

There are foods that make you happy. Well, maybe not happy, but satisfied. And that's why you do not even listen to them anymore - even if you are already full. This phenomenon is called in the jargon hedonic food intake. The good feeling is triggered by the neurotransmitter dopamine: tempting foods activate brain areas of the reward center, where the dopamine D2 receptor is found. Scientists from Henriette Schmidt-Burkhardt's Department of Food Chemistry at FAU have now wondered: Are there any special ingredients in foods that - similar to the body's own dopamine - activate the dopamine D2 receptor?

High beer consumption thickens and damages the organs. In small quantities, the popular barley juice can also serve and even make you happy. (Image: nitr / fotolia.com)

To find out, the researchers, together with colleagues from the Computer Chemistry Center of the FAU used the method of virtual screening, a well-known from pharmaceutical research approach. The food ingredients are initially not examined in the laboratory, but on the computer. The advantage: In contrast to classical 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 initially created a virtual database of 13,000 food molecules. From this database, it was important to find the molecules that fit the dopamine D2 receptor - the key to the keyhole. The computer calculated which molecules are likely to interact with the dopamine D2 receptor: either through synthetic substances already known to interact with the receptor, such as drugs to treat Parkinson's or schizophrenia, or through the three-dimensional structure of the receptor receptor. In the end, of the 13,000 options, 17 remained, which were then tested in the laboratory in cooperation with the Department of Pharmaceutical Chemistry of FAU.

Surprise find beer
The most promising test results showed the substance Hordenin, an ingredient of barley malt and beer. "It is surprising that - without us looking specifically for the group of stimulants - an ingredient of beer leads to the activation of the dopamine D2 receptor", says Prof. Dr. med. Monika Pischetsrieder.
Just like dopamine, hordenin activates the dopamine D2 receptor - with one important difference: it works through another pathway. In contrast to dopamine, hordenin activates the receptor exclusively via so-called G proteins, which could lead to a more lasting effect on the reward center. Whether the quantities contained in the beer are sufficient for a noticeable influence on the reward center, the researchers are currently investigating. Overall, however, the results indicate that hordein could contribute to the mood-enhancing effect of beer. (sb, pm)

The scientists published their results in Scientific Reports: Sommer, Thomas; Hübner, 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.