Allium vegetables — edible bulbs including onions, garlic and leeks — appear in nearly every cuisine around the globe. They are fundamental in classic cooking bases, such as French mirepoix (diced onions, celery and carrots), Latin American sofrito (onions, garlic and tomatoes) and Cajun holy trinity (onions, bell peppers and celery). While we sometimes take these standbys for granted, the flavor of allium vegetables cannot be replicated. And neither can their health benefits, which include protection from heart disease and cancer.
Allium vegetables have been treasured over the millennia; onions, with origins in Asia, Iran and West Pakistan, are the most widely cultivated species of the allium genus and have been grown for over 5,000 years. The allium genus consists of up to 1,250 species, many of which are grown as ornamental flowers.
Health benefits in the bulb
Allium vegetables have a long rich history in traditional medicine. A review article in the Journal of Nutrition reports that garlic was one of the earliest documented plants used for health benefits and disease treatment in medical texts from Egypt, Greece, Rome, China and India. Today, scientists know that allium vegetables have anti-microbial, anti-tumor, anti-arthritic, anti-clotting and blood sugar-lowering actions. These benefits are likely related to allium’s many health protective compounds, including vitamin C, the phytochemical quercetin and organosulfur compounds, which are responsible for alliums’ characteristic flavor and aroma. In particular, alliums may be beneficial for cardiovascular disease and cancer protection.
Quercetin has been linked with cardiovascular health. Onion supplements containing quercetin lowered blood pressure in people with hypertension, according to a recent study in the British Journal of Nutrition. And garlic has a long record of use as a heart remedy. A recent meta-analysis of more than 100 studies found that garlic was linked with reduced blood lipids, blood glucose and blood pressure levels.
The European Prospective Investigation into Cancer and Nutrition study found that higher intakes of onion and garlic were associated with reduced risk of intestinal cancer. Data from The Iowa Women’s Study showed that women with the highest garlic consumption had a 50 percent reduced risk of distal colon cancer compared with those eating the lowest amount. While the mechanisms for cancer prevention are not yet fully understood, the organosulfur compounds are thought to play a role.