This Allium family plant has cardiovascular benefits similar to those offered by its cousin, garlic. Onion is rich in sulfur, and so helps to prevent blood clots. Onion is used all over the world as a remedy for colds, flu, and coughs. The powder is a delicious seasoning, great in chili, taco mix, salad dressing, marinades or dry rubs. When recipes call for fresh onion, you may substitute 1 tablespoon onion powder for every medium onion.