The metallic taste, known as dysgeusia, occurs when certain compounds activate taste receptors or irritate the nerves that transmit taste sensations, creating a perception similar to that of metal.
In the case of red wine, tannins and antioxidants such as resveratrol can stimulate the nerve endings on the tongue, especially when the mouth is dry. Foods or medications that contain metallic ions (for example, iron, zinc or bismuth) can also react with proteins in saliva and produce a direct metallic sensation.
The intensity of this taste varies from person to person due to genetic differences in taste receptors (certain variants make some people more sensitive to bitter or metallic flavors), hydration levels, the presence of oral health issues, and the composition of the oral microbiota. Factors such as fasting, stress or the use of other medications can also alter taste sensitivity, causing the same food to be perceived very differently from one person to another.
In short, the metallic taste results from the interaction between compounds found in foods or medications and the taste receptors and nerves, and its intensity depends on each person's individual sensitivity, influenced by genetics, hydration, overall health and the oral environment.
