How long does your food last?

Since we're not big juice drinkers in our house, OJ usually only makes its way into our fridge when guests come to visit. Even then, it still takes us a few weeks to polish off the carton. I never thought much about keeping the OJ for a few weeks. After all, it still tastes good—and we usually finish it before the expiration date. Then I read this study that showed opened OJ loses all antioxidant benefit after just one week! Seriously? Well, as you can imagine, this led me to wonder if other items in my kitchen lose their health punch over time. (Spoiler alert: they do!)

Keep track of how long you store these 4 items. Here's why: certain nutrients are unstable when exposed to oxygen (from the air), heat (from cooking) and light.

Orange juice: 1 week
One cup of OJ can offer a full day's dose of vitamin C. But OJ that has been opened loses all antioxidant benefit after just one week. To get the most vitamin C, buy frozen concentrate and drink within a few days. Frozen concentrate is exposed to less light and air. (Use your OJ before it loses its nutritional punch: make Grilled Orange Chicken Fingers and more delicious recipes with orange juice.)

Green tea: 6 months
A 2009 study in the Journal of Food Science showed that catechins (antioxidants linked with a reduced risk of some cancers) in green tea decreased markedly over time. After six months, catechin levels were 32 percent lower. Make the most of the antioxidants by storing tea in a sealed container in a dark, cool place.
(Add this 1 ingredient to your tea to make it healthier.)

Olive oil: 6 months
Extra-virgin olive oil contains more than 45 heart-healthy antioxidants, but after six months of storage their potency decreases by about 40 percent, according to researchers at the University of Foggia in Italy. Why? Oxygen bubbles in the bottle destroy the antioxidants.
(Find out which brands won our Olive Oil Taste Test and find out how to shop for the healthiest and tastiest olive oil.)

Honey: 6 months
Researchers at the University of Illinois found the antioxidant power of clover and buckwheat honey decreased by 30 to 50 percent after six months. Consider buying buckwheat honey—it generally has more antioxidants to start with.
(Can honey help you lose weight?)

By Brierley Wright, M.S., R.D.