Onions have also been shown to have a significant blood sugar-lowering action, even comparable to some prescription drugs.
The active compound that seems to be responsible for lowering glucose works by competing with insulin for breakdown sites in the liver, thereby increasing the life span of insulin.
Onions have historically been used to treat asthma, too. Its action in asthma is due to its ability to inhibit the production of compounds that cause the bronchial muscle to spasm and to relax bronchial muscle.
Onions have potent antibacterial activity, destroying many disease-causing pathogens, including E. coli and salmonella.