Although not a component of sweat, what's on your skin is also responsible for why you smell. In fact, there are 100 different volatile organic compounds on human skin, the largest organ on your body. One is benzothiazole, a smelly sulfur compound often used as a food additive. Scent scientists suspect that the concentration of these compounds varies with age. [sources: Ara et al., Monell Center].
Beyond the science of stink, eventually all those VOCs emanating from skin may signal health problems, if we develop the technology to detect them.