פירוש על ברכות 71:4

SINCE HE DERIVED PLEASURE FROM IT, HE MUST RECITE A BLESSING. And it appears that the matter is as follows: That if one drinks liquids, if the liquid is bad to drink to the extent that he has no pleasure from it, he need not recite a b’rochoh.

That one may swallow oil added to an elaiogaron on the Sabbath ; so why is it mentioned ?

The fact that it is permitted on the Sabbath proves that legally it is something to be enjoyed, the healing property being only incidental. And further, since the mixture is taken because of the oil, this is the principal