There is a huge difference between moral relativism, and the actual belief that there is no truth.
The idea that there is no truth is a contradiction in itself that it says there is no truth, which is a statement that intends to be true when in fact, if there is no truth, it cannot be true. I imagine people who don't believe in truth must have their heads spinning in circles. By the way, I don't see much difference between the two beliefs; obviously you need to be pretty crazy to believe either.
Personally, my scientific opinion on it is that there is a fundamental truth to everything (I see no logic in this not being the case - everything must be something, or else there would be nothing), but that it may well be impossible to ever know if what we have is indeed that truth.
I also don't feel that the chance of that impossibility should impede us from trying, however, an idea which would be lost on opebo.