THE HEALTH BENEFITS OF RED ONIONS. THE HEALTH BENEFITS OF ONIONS

RED ONIONS

The common onion group includes both shallots and potato onions.

For all varieties of onions, the more phenols and flavonoids they contain, the more their antioxidant and anticancer properties.

In general, the most pungent onions delivered many times more health benefits than their milder cousins.

Shallots have the most antioxidant activity, followed by Western Yellow, pungent yellow, Northern Red, Mexico etc. The milder-tasting cultivars with less cancer fighting abilities are 'Western White,' 'Peruvian Sweet,' 'Empire Sweet etc.

Eye irritation can happen when peeling onions, due to it’s gas that reaches the eyes. This can be avoided by cutting onions under running water or submerged in a basin of water. 
Another way is do not cut off the root of the onion (or do it last), as the root has a higher concentration of enzymes.  
Chilling or freezing onions before cutting, prevents the enzymes from activating, so lesser gas is generated. Use a sharp knife to chop onions will limit the cell damage and lessen eye irritation.

Health Benefits of Red Onions: Sulfur Compounds

One group of chemicals responsible for the health benefits of red onions are the chemicals that produce the odors of onions ( sulfur-containing allyl propyl disulphides). These sulfur compounds may help reduce the risk of heart diseases and the risk of head and neck cancers.

Health Benefits of Red Onions: Flavonoids

Flavonoids, prevent oxidative damage that can lead to cancer and heart disease. The most important flavonoid in onions is known as quercetin- a powerful anti-inflammatory and anti-oxidant, that may prevent the growth of certain types of tumors.

Quercetin also has natural anti-histamine properties which may make onions somewhat effective against allergy symptoms. 
All onions have quercetin, but red onions have the most. Red onions, over its paler counterparts, are lower in calories and fat.

Onions are extremely helpful in fighting chronic pain and inflammation.

Quercetin, inhibits the inflammation present in “Osteoarthritis” and “Rheumatoid Arthritis”. Onions destroy the bad “osteoclats”, which break down bones.

Onions flavonoid acts much like Fosamax. Fosamax is a very successful bone strengthener drug, but, it’s beneficial effects gradually disappear if the drug is discontinued.  (excerpts only-  wiki and yahoo contributors)