Ginger is known to activate the immune system. This argument is now supported by new findings from the Leibniz Center for Food Systems Biology at the Technical University of Munich. Small doses of the spicy ginger ingredient increased the vigilance of white blood cells in laboratory testing. This process also involves a type of receptor that, according to the study, is involved in experiencing unpleasant thermal stimuli and the sensation of spiciness in food.
Whether as a medicinal plant or as a food, ginger is also increasingly popular in Germany. According to the German Federal Statistical Office, the annual import volume of the fruit-burning root has almost quadrupled over the past ten years to around 31,600 tonnes. However, even though ginger consumption has increased, the question arises as to whether normal levels of consumption are sufficient to produce health effects. And if so, which compounds and molecular mechanisms play a role?
To help clarify these questions, a team led by Veronica Somoza, director of the Leibniz Institute in Freising, Germany, conducted extensive research. The starting point was the result of an earlier pilot study, in which the first author Gaby Andersen from Leibniz-LSB@TUM also played a key role. As the study shows, a significant amount of ginger’s pungent compounds enter the blood about 30 to 60 minutes after consuming one liter of ginger tea. By far the highest levels were achieved with gingerol, with plasma concentrations of approximately 7 to 17 micrograms per liter.
The pungent compound is known to exert its “taste” effect through the so-called TRPV1 receptor, an ion channel located on the surface of nerve cells that responds to painful thermal stimuli, just like the pungent compounds in chili and ginger. Since some studies suggest that white blood cells also have this receptor, the research team tested whether [6]-gingerol affects the activity of these immune cells.
In the first step, the team managed to detect the receptor on neutrophil granulocytes. These cells make up about two-thirds of white blood cells and serve to fight against invading bacteria. Further laboratory experiments by the research group also showed that even a very low concentration of almost 15 micrograms of [6]-gingerol per liter was sufficient to put the cells on high alert.
Thus, compared to control cells, the stimulated cells responded about 30 percent more strongly to the peptide, which simulates a bacterial infection. Addition of an inhibitor specific for the TRPV1 receptor reversed the [6]-gingerol-induced effect.
“At least in the experiments, a very low concentration of [6]-gingerol is sufficient to influence the activity of immune cells via the TRPV1 receptor. In theory, these concentrations could be reached in the blood by consuming about one liter of ginger tea,” says Gaby Andersenová.
“Thus, our results support the assumption that the intake of regular amounts of ginger may be sufficient to modulate the cellular responses of the immune system. Nevertheless, there are still many unanswered questions at the molecular, epidemiological and medical level that need to be addressed with the help of modern food and health research,” concludes Veronika Somoza.
