I'm not sure. Something about OP's description tells me he was referring to wars in which the other side was the aggressor (because he calls it a "curse", and besides, if early wars are such a problem, then just don't start them.)
Score really is irrelevant, especially in the early game where AI advantages pull it up, you can always overtake them later. So much of the score comes from things like wonders and religion, that it really is not very important.
If it is a defensive war (i.e. one not initiated by you), then I don't see why it should be pushing your score down unless you were really losing. Just defend, don't go on the offensive. It's going on the offensive that pushes your score down as you need a larger army to attack. If you only intend to defend, then the only units you need to use are the defensive units that you would have built anyway, even if there hadn't been a war.
If anyone's score is going to be plummeting, it's your opponent's. He's the one wasting resources on units that get killed by you. Just as long as you make sure he doesn't pillage any tiles. And you get XP out of the war, too.