Clothing of any kind will provide some protection to the skin. The crux of the whole "helmet debate" is, if you're going to choose to wear one, do so fully informed, knowing its limitations and acting accordingly. Education (facts, data, physics, materials engineering, biology, etc) has convinced many of us that -- carrying the whole protective clothing analogy further -- cycling helmets are the Emperor's New Clothes. And then there's the whole issue of how marketing has sold this massive con on an unsuspecting population, while making cycling look far more dangerous than it is and making people on bikes look "other". Lies and divisions and dirty tricks.