Yes, well, that's what it does. In order to prevent the body rolling it adds to the spring rate on the outer wheel during a turn. It also reduces the spring rate on the inner wheel because it works against the suspension spring on that side. It's all a balance of forces, you don't get anything for nothing. An antiroll bar improves the handling but reduces the road holding at a given cornering speed because the outer wheel/tyre is under greater load. It's a plus/minus thing in suspension design and always a compromise. The functioning of the antiroll is such that it is sometimes working and other times not. There's good reason why road vehicles don't just employ massive antiroll bars so we can all just ride around nice a level!