Only young asparagus shoots are commonly eaten: once the buds start to open (“ferning out”), the shoots quickly turn woody.
Asparagus is low in calories and is very low in sodium. It is a good source of vitamin B6, calcium, magnesium and zinc, and a very good source of dietary fiber, protein, vitamin A, vitamin C, vitamin E, vitamin K, thiamin, riboflavin, rutin, niacin, folic acid, iron, phosphorus, potassium, copper, manganese and selenium, as well as chromium, a trace mineral that enhances the ability of insulin to transport glucose from the bloodstream into cells. The amino acid asparagine gets its name from asparagus, as the asparagus plant is rich in this compound.
The shoots are prepared and served in a number of ways around the world, typically as an appetizer or vegetable side dish.