A food supplement of therapeutic composition is provided suitable for the treatment or prophylaxis of COPD and other acute or chronic diseases in a mammal, especially a human being, comprising at least one of glutamate, other than mono sodium glutamate, and a precursor of glutamate selected from the group consisting of leucine, valine, isoleucine, and a keto acid thereof, in a daily dose for said mammal of at least 6 grams, preferably between 9 and 20 grams, of the total of said glutamate and precursor forms thereof.