Prized for its unique flavor and texture, asparagus has long been revered as a “luxury” vegetable. In fact, its history as an aristocratic edible dates back to the ancient Egyptians who cultivated the spindly shoots as offerings for their gods.
But asparagus’s high-brow reputation isn’t just culinary, it is high-class in its nutritional attributes, as well. The National Cancer Institute has noted that asparagus is the food highest in glutathione—a powerful detoxifying enzyme, produced by the liver. Asparagus also boasts folate, potassium, and calcium, as well as the mineral selenium and the sight-saving nutrients lutein and zeaxanthin.
The optimum season for fresh asparagus lasts from February through June, although hothouse asparagus is available year-round in some regions. It’s best cooked the same day it’s purchased but will keep, tightly wrapped in a plastic bag, 3 to 4 days in the refrigerator. Or, store standing upright in about an inch of water, covering the container with a plastic bag.
Jones, D.P. Glutathione in foods listed in the National Cancer Institute's health habits and history food frequency questionnaire, Nutrition and Cancer 17 (1), p. 57, 1992.