Soy is celebrated as a superfood by some who claim it can fight heart disease, hormone-related cancers, and osteoporosis while providing a potent plant-based protein source. But others tell us that it’s a central driver of breast cancer, thyroid problems, dementia, and environmental problems like deforestation. So what’s the truth? Is soy good for you? And what are the health and environmental consequences of consuming it? Here’s what you need to know about soy.