The onion market varies in color, including red, green and white.
Red onions help fight germs and infections, and oils reduce the severity of coughs and heal colds.
This type of onion reduces the sensitivity of the body, because it contains a substance that helps inhibit the action of stimulating hormones for allergies accompanied by itching and runny nose, as well as maintaining the health of the cardiovascular and arteries.
Red onions lower cholesterol, prevent blood clots and hardening of the arteries, help prevent cancer cells and boost the immune system, according to Sky News.
The white onion is an important antiseptic for the mouth of bacteria and germs, and also addresses respiratory problems, such as infections of the lungs, nose and throat as well as the trachea.
White onions work to alleviate the severity of asthma symptoms, treats cases of leaching and helps in the healing of cough and get rid of the accompanying phlegm.
White onions play a role in fertility in men, by stimulating blood circulation, as well as helping to keep the body's cells from being damaged.
Onions, whatever their color, contain several minerals and various vitamins important to the human body, and is a low-calorie vegetables.