Walnuts are a tree nut with powerful antioxidants and anti-inflammatory properties. They have a high concentration of healthy fats, vitamin E and omega-3 fatty acids. In fact, just 7 walnuts contain 60% of your daily value of omega-3s! They also contain manganese, copper and biotin. Studies show that walnuts help to boost the immune system, brain function, heart health, beneficial gut bacteria and metabolism.