How fast does food lose nutrients?

It's safe to say that the asparagus that's turning blue in the bottom of your vegetable crisper is no longer the nutritional powerhouse it once was. (It's safe to say it'll make you turn green if you eat it, but that's another story.) Most foods that are naturally rich in vitamins, minerals, and other healthy stuff lose some of that nutritional wealth over time. How fast nutrient depletion happens depends on the food. For example, a carton of orange juice loses all of its disease-fighting antioxidants just a week after its opened. A bottle of olive oil loses its antioxidant capacity at a much slower rate (it will have lost a significant percentage of its nutrients within six months of opening the bottle). Fruits and veggies lose about 50% of disease fighting nutrients within a week, but frozen generally lose only that much until you thaw, Whether you buy fresh, frozen, or canned food, a general rule holds true: The sooner you consume it, the better.