Onions have been used traditionally to treat diabetes. Animal studies suggest onion extracts may help reduce high blood glucose levels.²³ Onion and its constituents have been shown in the laboratory to inhibit enzymes involved in the breakdown and digestion of starches and other carbohydrates, as well as enzymes involved in glucose metabolism.^24,25 Onion has further been found to stimulate insulin responsiveness and glucose uptake by cells.²⁶ Preliminary trials have found eating onions, in amounts of 60 and 100 grams (about 2 and 3.5 ounces) per day, lowered fasting blood glucose levels and the fasting response to glucose ingestion (glucose tolerance) in subjects with type 2 diabetes.^27,28

Research in laboratory animals suggests onion and its active constituents may lower blood glucose levels, raise insulin levels, reduce advanced glycation end-product (AGE) formation, and possibly prevent diabetes complications.^29,30,31 In one preliminary trial, people with type 1 diabetes had lower blood glucose levels four hours after eating about three ounces of raw onion than after receiving water.³²

 

The mucilage of slippery elm gives it a soothing effect for coughs. Usnea also contains mucilage, which may be helpful in easing irritating coughs. There is a long tradition of using wild cherry syrups to treat coughs. Other traditional remedies to relieve coughs include bloodroot, catnip, comfrey (the above-ground parts, not the root), horehound, elecampane, mullein, lobelia, hyssop, licorice, mallow, (Malvia sylvestris),red clover, ivy leaf, pennyroyal (Hedeoma pulegioides, Mentha pulegium),onion, (Allium cepa), and plantain (Plantago lanceolata, P. major). None of these has been investigated in human trials, so their true efficacy for relieving coughs is unknown.

 

Herbs that directly attack microbes include the following: chaparral, eucalyptus, garlic, green tea, lemon balm (antiviral), lomatium, myrrh, olive leaf, onion, oregano, pau d’arco (antifungal), rosemary, sage, sandalwood, St. John’s wort, tea tree oil, thyme, and usnea.

 

Onion may act as an anti-inflammatory in people with asthma. Human studies have shown onion can be a strong anti-inflammatory.³³ However, some people with asthma may experience an exacerbation of symptoms if they are allergic to onion and are exposed to it.³⁴

 

Onion injections into the skin and topical onion applications have been shown to inhibit skin inflammation in people with eczema, according to one double-blind trial.³⁵ The quantity or form of onion that might be most effective is unknown.