Our Shift From Pungent To Sweet Onions Likely Cost Us Precious Phytonutrients
Our craving for sweetness (sugar) in nearly all of our food products has led plant breeders to seek out and select varieties with higher percentages of sugar content, but in many cases this has led to varieties that are lower in the precious phytonutrients that transfer protection from the plant’s pest-and-disease-immune system to our body’s immune system. This is especially true in the case of onions, according to nutritional research reported by organic gardener and author Jo Robinson in her book Eating on the Wild Side.
“Until about 70 years ago, all of the varieties of onions sold in this country were pungent and potent,” says Robinson, “giving consumers a wide range of phytonutrients and antioxidant protection. Around the middle of the 20th century, new varieties of onions were introduced that had more sugar and a lot less medicine. The first of the sweet orbs was created by a French soldier named Peter Pieri, who discovered an unusually large, mild and sweet variety of onions growing on the Mediterranean island of Corsica. In 1900, he gathered their seeds and brought them with him when he settled in the Walla Walla Valley in Washington State.”
Robinson notes, “Pieri began a breeding program to make the Italian imports even milder, sweeter and larger. Each year he selected the onions that came closest to his vision and saved their seeds for the next planting. With the aid of his sons and other growers, he achieved his goal in the 1940s. Washingtonians loved Pieri’s sweet, juicy onions, and the variety was soon outselling more robust onions throughout the state. In the 1960s, a marketer gave them the appealing name Walla Walla Sweets, and the meek onions found a ready market across the country.”
She states that throughout the 1950s and 60s, “Other varieties of extra-mild, extra-large onions began to appear in the nation’s grocery stores, including Vidalia, Texas 101 and Bermuda onions. Americans snapped up these mild-mannered alliums, which motivated growers to create even larger and sweeter varieties. Today we can dine on onions named Jumbo Sweet, Sweetie Sweet and Candy Cane that have as much as 16 per cent sugar, the same percentage found in our sweetest apples.”
Robinson reports recent research shows that our trend to the sweeter onions may well have left us more susceptible to modern diseases—including cancer. “In a 2004 test-tube study, extracts of strongly-flavored onions destroyed 95 per cent of human cancer cells of the liver and colon,” she says, “whereas extracts of sweet onions only killed 10 per cent. Sweet onions are also less effective at thinning the blood, so they are less able to lower the risk of heart attack and stroke.
“Increasing the size of the onions was another nutritional misstep,” she continues, “The smaller the onion, food chemists have discovered, the less water it contains and therefore the greater its concentration of phytonutrients. Two small onions give you twice as many antioxidants as one large onion of the same variety. The mildness, high sugar and water content and large size of the supersweet onions work together to lower their antioxidant content.”
When choosing onions to grow for nutritional and medicinal values, Robinson recommends varieties that are red and pungent, yellow and pungent and all varieties of scallions. “All varieties of red or yellow, pungent onions are rich in antioxidant values, and their flavor mellows dramatically when cooked. All varieties of scallions are one of the most nutritious of all the different species of onions.” But she adds that there is also a place in our diets for the sweet onions, since “They are a reasonable choice if you want to eat raw onions, whereas the raw, pungent onions would overpower all other flavors in a salad or sandwich.”