About half of all tourists making their way to the Inca ruins of Machu Picchu will experience altitude sickness. Once you arrive in the Andean city of Cusco, climbing even the smallest flight of stairs will leave you out of breath. You slowly forget what it’s like to feel hungry and, at times, you might even feel like throwing up for no apparent reason. In the evening, a persistent headache will prevent you from falling asleep, no matter how tired you are.
If your symptoms get out of hand, you can always buy some pills at the nearest pharmacy. But the locals have a quicker, better, tastier remedy: coca tea. Sold in just about every café, restaurant, and hostel, coca tea consists of hot water and coca leaves—the same leaves that are used to make cocaine. In the Peruvian highlands, use of the coca plant precedes the invention of the
