It is an immediate cure for fever, common cold, cough, sore throat, allergies etc. A mixture of onion juice and honey can cure these problems easily. Several servings of onion each week are sufficient to statistically lower your risk of some types of cancer. For colorectal, laryngeal, and ovarian cancer, between 1 7 servings of onion has been shown to provide risk reduction. But for decreased risk of oral and esophageal cancer, youll need to consume one onion serving per day (approximately 1/2 cup).