Cashews are a kidney-shaped seed sourced from the cashew tree — a tropical tree native to Brazil but now cultivated in various warm climates across the world. Although commonly referred to as tree nuts, and nutritionally comparable to them, cashews are really seeds. They’re rich in nutrients and beneficial plant compounds and make for an easy addition to many dishes. Like most nuts, cashews may also help improve your overall health. They’ve been linked to benefits like weight loss, improved blood sugar control, and a healthier heart.