I stand corrected - raking the rudders will eliminate or reduce (or even make negative) the tendency of the boat to round up into the wind...i.e. "weather helm". What I should have said, as Will put it, that raking the rudders does not change the amount of load on the foils under the water but only the amount of it you feel.

P.S. If you rake the rudders too much, you'll get lee helm and this is bad. With lee helm the boat will be turn downwind and sail away if you fall off.