Anemia: The high content of iron in onion makes it beneficial for the treatment of anemia.
Anti-coagulant: Just by eating half a medium raw onion daily can significantly lower cholesterol and help prevent heart attacks.
Anti-inflammatory: The anti-inflammatory agents in onion are useful in reducing the symptoms of inflammatory conditions such as arthritis and gout.
Anti-septic: Fights infection bacteria, including E.coli and salmonella, and is effective against tuberculosis and infections of the urinary tract, such as cystitis.
Blood pressure: Whether you eat it raw or cooked, onions help to lower blood pressure naturally. It also thins the blood, dissolve blood clots and clear the blood of unhealthy fats.
Cholesterol: Eating half a medium raw onion daily significantly helps to correct thrombosis, lower the LDL cholesterol and prevents heart attacks.
Colon cancer, prevention: Fructo-oligosaccharides in onions stimulate the growth of good bacteria in the colon and help reduce the risk of tumors developing in the colon.
Constipation and flatulence: Add plenty onion in your cooking to help relieve chronic constipation and flatulence.
Diabetes: Chromium in onion helps diabetics' cells respond appropriately to bringing down the insulin level and improve glucose tolerance.
Diuretic and blood cleansing: Help counter fluid retention, urinary gravel, arthritis and gout.
Ear disorder: In some culture, cotton wool is dipped into onion juice and put into the ear to stop ringing in the ear.
Hair loss: A study has shown that applying onion juice on scalp twice a week for 2 months will cause hair regrowth. Definitely cost much less that those hair tonic.
Immune booster: The pungency increases blood circulation and causes sweating. Useful in cold weather to ward off infection, reduce fever and sweat out colds and flu.
Osteoporosis: A compound has recently been identified in onions that prevents the activities of breaking down bone. Especially beneficial for women who are at risk for osteoporosis as they go through menopause.
Respiratory: Mix equal amounts of onion juice and honey and take 3-4 teaspoons of this mixture daily. It helps liquefy mucus and prevents its further formation. It is also one of the best preventive potion against common cold.