>"The indiginous people say it helps them with altitude. "
Not naming names, but someone I know spent time in Bolivia. When they weren't providing medical care, they'd hike around including one time up a 21,000-foot peak. The coca leaves seemed to help or maybe made them not care so much.
The taste was described as, yeah, not bad, but sort of what you'd imagine a cow's diet to taste like. As opposed to the potatoes - dried in the sun interspaced with being walked on in dirty bare feet to squeeze more water out of them (preservation through disication) which they reported as tasting like chewy dirt.