Onions (Allium cepa L.) are a healthful food. Epidemiological (i.e., population-based) studies have repeatedly shown that people who eat diets rich in fruits and vegetables, and particularly in garlic and onions, have lower rates of chronic diseases, including cardiovascular disease and cancer. I try to incorporate garlic and onion, as well as their elegant cousin, the shallot (Allium ascalonicum), a small but subtly flavored relative of the onion, into my diet whenever possible. For instance, I make a mean omelet using an entire onion, lightly sautéed, with some garlic cloves thrown in for good measure.

But, as you may have noticed, there have been changes in the onion business that bear watching. First of all, the price of onions has risen in recent years. It is not uncommon these days to pay $1.50 per pound for what not long ago cost 39¢. And increasingly in American supermarkets, the familiar yellow, white and red onions are being crowded out by various "sweet" varieties. These sweet varieties used to be sold at a premium but are now actually somewhat less expensive. (On a recent shopping expedition I noticed that they were the only bulk onions priced under $1.00 per pound).

Originally, the only variety of sweet onion available in most markets was a form of yellow granex known by the name Vidalia. Traditionally, these were harvested in southeast Georgia from late April till mid-June and were available only during the summer months. Now the Vidalia season has been extended for several months by use of controlled atmosphere (CA) storage. The principal characteristic of CA storage is a modification of the atmosphere in the storage facility. This involves decreasing the oxygen content of the air to 3 percent and maintaining the onions at a temperature of 34 degrees Fahrenheit. So there are now Vidalia and other sweet onions available in many markets year-round.

The Vidalia sweet onion was discovered by a farmer named Mose Coleman in Toombs County, Georgia, in the spring of 1931. During the depths of the Great Depression, Mose was able to get a whopping 7¢ per pound for his novel onions, and word of this quickly spread. The state of Georgia subsidized a farm stand in the Toombs County town of Vidalia, and tourists who bought Mose's delicious onions as a novelty spread word of them far and wide.

Figure 1: Mose Coleman, discoverer of the Vidalia onion If you cannot view the photo above,please click or go to: http://www.cancerdecisions.com/images/farmer_mose.jpg

Soon these so-called "Vidalia onions" began appearing on the shelves of the local Piggly Wiggly - and the Vidalia became synonymous with a fine eating onion that wouldn't cause tears when you cut it up. Down along the banks of the Ogeechee River, folks are understandably proud of their unusual onion. In 1990, the Vidalia onion was named Georgia's official state vegetable. Like French wines, "Vidalia" is now a controlled appellation that can only come from a production area defined by law in Georgia and by the United States Code of Federal Regulations (CFR). According to the Vidalia Onion Act of 1986 true Vidalia onions can only come from certain well-defined counties.

Vidalia onions have a very mild taste and do not make your eyes water when you cut them up. In time Vidalia was joined on the shelves by other varieties of sweet onions - Maui, Walla Walla, and Maya. These are all delicious. Some are available all year long and at 50 percent lower cost than standard yellow or red onions.

Chemical analysis has shown that the reason that these onions are so sweet is because of a lack of sulfur in the soil in the particular counties in which they are grown. Sulfur is necessary to produce the characteristically sharp taste and odor of typical onions. But therein lies the problem. Do these sulfur-lacking sweet onions convey the same health benefit as typical sharp onions? After all, we also know that sulfur is involved in the production of some of the very phenolic and flavonoid compounds that give the onion family its health benefit. (I am thinking in particular of organic allyl sulfur, the most desirable compound in onions and garlic.)

This question has been answered by food chemists at Cornell University and the results will not come as welcome news down in Jeff Davis County.