Whether in soups or stews, sauteed or roasted, we love this versatile food
Mention onions, and the immediate response you’re likely to get is, “They make me cry!” An intriguing theory as to why this is so can be found in ancient Turkish folklore: when Satan was cast down from Heaven, the spot where his right foot first touched the earth sprouted onions, thus bringing tears to humankind. Then there is the more prosaic, but undoubtedly more accurate observation provided by modern science, which explains that the weepy effect is produced by allyl propyl disulfide. This sulfur-containing compound is responsible not only for the onion’s pungent odor, but also for many of its health-promoting qualities.
Through the Centuries
Onions have been cultivated worldwide for more than 5,000 years. For much of their history, they were primarily eaten by the poor because of their ubiquity and pungency: ancient Egyptians used them as currency to pay weary workers at the pyramids; for centuries, raw onion sandwiches were a staple of Europe’s lower classes. But toward the end of the Middle Ages, the onion began to be recognized for the versatile and delightful vegetable it truly is. Once Columbus carried it to the New World, its culinary dominance was assured.
Its uses were not by any means confined to the kitchen. In sixth century India, onions were employed as a diuretic; Colonial Americans thought raw onions cured measles; and to this day in Chinese medicine, onions are said to calm the liver, moisten the intestines, and benefit the lungs.
Now About Those Benefits
The health benefits in onions derive primarily from the aforementioned allyl propyl disulfide, as well as chromium, vitamin B6, and a flavonoid called quercetin. Allyl propyl disulfide has been shown to lower blood sugar levels; in combination with chromium, it can lower insulin levels and decrease total cholesterol and triglyceride levels while increasing “good” HDL-cholesterol levels. When you stir vitamin B6 into the mix, you are rewarded with heightened protection against atherosclerosis, diabetic heart disease, heart attack, and stroke.
Which brings us to the quercetin. This antioxidant has been proven to be a potent fighter against intestinal and colorectal cancers, as well as breast, ovarian, and numerous other cancers. Add to this some significant anti-inflammatory and antibacterial properties, and quercetin indeed proves to be a formidable weapon in your healthful-living arsenal.
Getting the Good Stuff
Onions are divided into two basic categories—spring/summer and storage. The former are the “sweet” onions—Vidalia, Maui, and Walla Walla being among the better known—as well as spring onions (also known as green onions or scallions); they are more fragile, and cannot be stored for long. They are also milder tasting. As the name implies, storage onions—those with a dry outer husk and a more pungent flavor and aroma—can be put up longer.
In all instances, choose firm, dry onions with no sprouting at the top and no soft or moldy spots. Spring onions should be fresh, green, and tender—avoid any that are wilted and yellowed, and store in a plastic bag in the fridge. Store all other onions in a cool place with plenty of ventilation. Use sweet onions within a week, storage onions within a month.