Red onions, also known as Spanish onions, contain plenty of healthy essential nutrients as well as phytochemicals that provide long-term health benefits. Including red onions in your daily diet may help reduce your risk of chronic disease. Pungent yet flavorful, red onions can be enjoyed in salads, sliced for use on sandwiches or cooked into soups or other dishes.
A 1/2-cup serving of chopped onion contains only 32 calories and no fat or cholesterol, making it a healthy choice for those watching their fat or calorie intake. A serving also contains 1.5 grams of fiber. Fiber helps improve the functioning of the digestive tract, and it helps prevent constipation. Red onions also contain plenty of vitamins and minerals, including folate, thiamine, calcium, magnesium, potassium, manganese and vitamins C, K and B-6. Consuming foods with a variety of nutrients helps keep the body healthy on a day-to-day basis and may help prevent chronic disease.