Though onion juice can be used in recipes to add onion flavor without any actual onions, it is often purchased or made in the interest of improving health. For centuries, onions have been prized for various medicinal uses, from easing congestion to even helping to cure cancer. Onion juice allows those employing these remedies to easily work this vegetable's reportedly healing properties into a vegetable cocktail, soup or tea.
It is fairly trouble-free to obtain the juice from an onion, which could be any of several species from the lily family of root vegetables. Some purchase it at a health-food store or an online vendor. These come with brand names like Reese® or Howard's®. Others use a dedicated juicer to get it fresh from the source, or just grate onions and squeeze juice from the pulp with a cheesecloth. The juice can then be disguised in a tea or added to just about any recipe.
Through several generations, onion juice has taken on a storied reputation for being an effective anticoagulant, antiseptic and provider of needed vitamins A, B and C. Some of its more common reported uses are to improve circulation, lower cholesterol, spur urination, ease respiratory disorders, and even settle symptoms of alopecia when applied topically. This compound also is a fairly accepted treatment to battle or resist cancers of the digestive tract.
Certain onion juice might have more medicinal worth than others though. In 2004, a study of 10 different onion species at Cornell University revealed that the varieties with the highest concentrations of phenolics and flavonoids had the most anti-cancerous and antioxidant ability. These included shallots as well as the western yellow, northern red and pungent yellow varieties of onions. As a general rule, those lily varieties with the strongest flavor and scent will have the most of these beneficial compounds.
These remedies, however, often require high dosages of the extract throughout a day — something with which onion juice can help. Its uses in savory dishes are numerous. Some also disguise it in mint teas or a sweet fruit smoothie, where its flavor will be masked by the prevailing ingredients. Many others just try to incorporate more of these vegetables into the diet, finding more recipes that use onions and adding more to regular diet staples that already have them.
Many consider onion juice to be one of many preventative measures that could help a body ward off disease or illness. To get the widest variety of essential nutrients, many health-conscious eaters try to add a diverse spectrum of vegetables and fruits to their diet. This includes the greens of the leaves, the browns and whites of the root vegetables, and the many other reds, yellows, oranges and purples of the garden's harvest.