The guy is as close to an expert in this field as it gets right now. If he says lots of meat is bad, I tend to believe him. One day we'll know exactly how and w

The guy is as close to an expert in this field as it gets right now. If he says lots of meat is bad, I tend to believe him. One day we'll know exactly how and why, but right now I trust him. And a bit of speculation: lots of heavy metals accumulate up the food chain. If you eat an onion, that's one onion's worth of heavy metals extracted from the ground. But if you eat a chicken leg, it's a few kilograms worth of plant that accumulated in it. And when you feed them animal protein it concentrates even further. Over a lifetime it's probably a difference of an order of magnitude between a meat-eater and a vegetarian.