In 1989, a Chinese study found that people who ate the highest amounts of allium vegetables in their diet, i.e.. onions, shallots, leeks, chives, garlic etc., had the lowest rate of stomach cancer. An independent study carried out in the United States at around the same time would seem to reinforce this theory.
The ancient physicians used onion to treat diabetes and, once again, modern studies have only served to proved them right, as recently it has been discovered that onion does indeed play a part in reducing blood sugar levels. Cooked onions are good for the cardiovascular system, taking just about 1 tablespoon to reverse the tendency for the blood to clot after a fatty meal. It is now known to reduce high blood sugar levels and to promote an increase in ‘good’ cholesterol levels in the blood. In fact, just half a raw onion a day will boost it by 30%.