Believe it or not, onios are a very old and time-tested remedy for the treatment of diabetes! Studies have proven the highly effective property of onions to reduce sugar levels in the blood. Experiments were performed in India, where  patients were treated with onion juice and whole onions (from 25 to 200 gr. of onions). It was found that as more onions were included in the diet, the more blood sugar levels were lowered.  Both raw and cooked onions were beneficial. It is not clear, whether onions influence glucose metabolism in the liver,  stimulate  production of insulin, or protect it from destruction. The assumption was made that blood sugar levels were reduced due to the presence in onions of the substances  allicin and allyl propyl disulfide.

In 1923 substances were found  in onions that destroy sugar. Later, in 1960, studies succeeded in isolating antidiabetic compounds that stimulate insulin synthesis. In experiments on rabbits, these onion extracts had an effect equal to 77% of the usual dose of Tolbutamide.