Ginger has a reputation for stimulating the immune system. New results from the Leibniz Institute for Food Systems Biology at the Technical University of Munich now support this thesis. In lab tests, small amounts of a pungent ingredient in ginger put white blood cells on high alert. The study also shows that a type of receptor is involved in this process, which plays a role in the perception of painful heat stimuli and the perception of spiciness in food.
Whether as a medicinal plant or food, ginger is also becoming increasingly popular in Germany. According to the Federal Statistical Office, the annual import volume of the fruity, hot root has almost quadrupled to around 31,600 tons in the last ten years. But even if ginger consumption has increased, the question arises as to whether normal consumption is sufficient to achieve health effects. And if so, which connections and molecular mechanisms play a role.
Ginger compound enters the blood
To clarify these questions, a team led by Veronika Somoza, director of the Leibniz Institute in Freising, Germany, carried out extensive research. The starting point was the result of an earlier pilot study in which first author Gaby Andersen from [email protected] was also significantly involved. As the study shows, about 30 to 60 minutes after drinking a liter of ginger tea, significant amounts of hot ginger compounds enter the blood. By far the highest values were achieved by -Gingerol, with plasma concentrations of about 7 to 17 micrograms per liter.
It is well known that the hot substance unfolds its “taste” effect via the so-called TRPV1 receptor, an ion channel on the surface of nerve cells that reacts to both painful heat stimuli and hot substances from chili and ginger. Because some studies suggest that white blood cells also have this receptor, the research team tested whether -gingerol affects the activity of these immune cells.
The sharp compound stimulates the white blood cells
In a first step, the team succeeded in detecting the receptor on neutrophilic granulocytes. These cells make up about two-thirds of the white blood cells and serve to fight off invading bacteria. Further laboratory experiments by the research group also showed that even a very low concentration of just under 15 micrograms -Gingerol per liter is enough to put cells on high alert. The stimulated cells reacted about 30 percent more strongly to a peptide that mimics a bacterial infection than control cells. Addition of a TRPV1 receptor-specific inhibitor reversed the effect induced by -gingerol.
“Very little, at least in experiments -Gingerol concentrations are sufficient to affect the activity of immune cells via the TRPV1 receptor. In the blood, these levels could theoretically be reached by consuming about a liter of ginger tea,” says Gaby Andersen. “Thus, our results support the notion that ingestion of usual amounts of ginger may be sufficient to modulate the cellular responses of the immune system. However, there are still many unanswered questions at the molecular, epidemiological and medical levels that need to be addressed with the help of modern food and health research,” concludes Veronika Somoza.