The phytochemicals in onions improve the working of Vitamin C in the body, thus gifting you with improved immunity. Onions contain chromium, which assists in regulating blood sugar. For centuries, onions have been used to reduce inflammation and heal infections. Do you enjoy sliced onions with your food? If yes, rejoice! Raw onion encourages the production of good cholesterol (HDL), thus keeping your heart healthy. A powerful compound called quercetin in onions is known to play a significant role in preventing cancer. Got bitten by a honeybee? Apply onion juice on the area for immediate relief from the pain and burning sensation. Onions scavenge free radicals, thereby reducing your risk of developing gastric ulcers. Those bright green tops of green onions are rich in Vitamin A, so do use them often.