Onions contain high amounts of quercetin
Quercetin is a polyphenol compound in the flavonoid family of antioxidants. Yellow or red onions are the best source of this nutrient while white onions are lacking. The general rule of thumb is the more pungent an onion tastes and smells the higher the overall antioxidant value. This means mild and sweet onions generally are not as beneficial.
The quercetin compound is also found in red wine, apples, citrust fruits, olive oil and blueberries to name a few. The compound is linked with lower rates of all types of cancer due to its anti-inflammatory properties. It is also an excellent remedy for arthritis and other diseases caused by inflammation.
Quercetin is also thought to improve prostate health in men and therefore may be an effective weapon against prostate cancer. It has also displayed natural antihistamine properties thereby reducing allergic reactions and general allergies. Studies are being done on the potential benefits quercetin may have to help preserve healthy cholesterol levels (HDL) while suppressing unhealthy cholesterol (LDL).
Onions are rich in sulfur compounds
Sulfur compounds offer an array of health benefits not to be ignored. These odorous compounds are responsible for the pungent taste and smell of an onion as well as the release of eye-irritating gases when the flesh is cut. They are also responsible for the potent antimicrobial and antibacterial properties of the onion. In fact, onion can be used as a preserving agent for meat that needs to keep for a longer period of time.
Sulfur compounds have long been regarded as a cancer fighting nutrient. Like quercetin, they possess anti-inflammatory properties, which is why the onion is such a great combination of nutrients. There is also evidence that the sulfur compounds found in onions may improve the symptoms of asthma and other breathing problems related to inflammation.
Sulfur compounds also help to prevent blood clotting and therefore act as a superior natural blood thinner. This can prevent cardiovascular disease, high blood pressure, heart attack, stroke and arteriosclerosis (hardening of the arteries).
Onions are rich in other important vitamins and minerals
Onions contain high levels of vitamin C, copper, calcium, vitamin A, and vitamin E. Vitamins A, E and C are all excellent antioxidants. Copper is a mineral that is important in the maintenance of bone and joint health and integrity and may help women especially to prevent osteoporosis. Additionally copper is excellent for maintaining firm skin.
As if all of this weren’t enough, onions also may help to ward off bowel and stomach disorders. High onion consumption has been linked to lower risk of bowel cancer. It has also been linked to a lower risk of colorectal cancers. Organisms in the onion are thought to encourage healthy bacteria growth in the gut while inhibiting the growth of destructive bacteria.