The stronger an onion tastes, the better it probably is for your health.

Pungent shallots and certain varieties of yellow and red onions are highest in flavonoids that have potent antioxidant and cancer-fighting abilities, a new study determined. Sweet onions have lower concentrations of flavonoids. Try adding onions to soups, salads, and sandwiches for an antioxidant boost.

Flavonoids are antioxidants that mop up free radicals. Free radicals can damage cells and potentially contribute to chronic diseases such as cancer, heart and blood vessel disease, and diabetes. A recent study revealed that strong-tasting onions and shallots are highest in flavonoids and may inhibit the growth of liver and colon cancer cells. If you're trying to maximize your intake of antioxidants, choose scallions, shallots, and yellow and red onions over sweet or white varieties, which tend to have a lower concentration of antioxidants. Dark chocolate, tea, apples, and cranberries are other good sources of flavonoid antioxidants.

RealAge Benefit: Getting the right amount of antioxidants through diet or supplements can make your RealAge 6 years younger.

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