What is onion useful for, and why should you not neglect it?

1. A source of vitamin C, the main antioxidant that fights free radicals that accelerate aging. Important for strong blood vessels and rapid regeneration. Onions contain 8 to 19% of the daily value of vitamin C. 2. Contains other antioxidants. For example, the flavonoid quercetin, which has anti-inflammatory properties, helps the body produce vitamin E and protects against many forms of cancer. Every onion has antioxidants, but red and yellow onions have more than white ones.