"Can vegans stomach the unpalatable truth about quinoa?," thunders the headline of a recent Guardian piece. Hard to say, but reality check: It isn't just vegans who enjoy quinoa. Like many occasional meat eaters I know, I've been eating it for years. Quinoa is also big among gluten-intolerant ...

I am currently down in Bolivia working on a documentary about quinoa production and take issue with a number of points raised in your work. "And it's not without challenges. In Bolivia, second in production to Peru, great prosperity has come to many farmers. But communities in the ...