Brazil nuts are nutrient-dense seeds harvested from one of the largest trees in the Amazon rainforest, known primarily for being the world's richest food source of selenium. Just one or two nuts a day provide more than the daily recommended intake of this mineral, which is essential for thyroid function, immune health, and antioxidant protection. These large, crescent-shaped nuts have a rich, creamy texture and a slightly earthy flavor, making them a popular addition to trail mixes or a stand-alone health supplement.