My nose runs a bit no matter what I eat, so it's some sort of stimulation of chewing. But spices and radiant heat stimulate the mouth and sinuses and probably cause the phenomenon.
Spices and foods like onion, peppers, and garlic are very healthy for humans, because they can fight viruses by filling vulnerable areas of the body's cells when viruses attach with their oils. Older people sometimes have trouble digesting them,. though.
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