Health Value of Veggies Varies With Time of Day

It’s five o’clock, do you know where your broccoli is? We ask because it now appears that some vegetables may be healthier for you if eaten an certain times of day. True. Researchers at Rice University have found that fruits and vegetables don’t die the moment they’re harvested. In fact, they continue to respond to their environment, mainly light and dark, for days, increasing and decreasing certain antioxidants in response to changes. A Rice University news release reports that last year, researchers found that plants use their internal circadian clocks to defend themselves from hungry insects, ramping up production of insect-fighting chemicals a few hours before sunrise, the time that hungry insects begin to feed. For this year’s project, researchers used controlled lighting to set the circadian clocks of  cabbage, spinach, lettuce, zucchini, carrots, sweet potatoes and blueberries. In the case of cabbage, at least, the researchers were able to manipulate cabbage leaves to increase their production of anti-insect metabolites at certain times of day. One of these, an antioxidant called glucoraphanin, or 4-MSO, is a known anti-cancer compound that has been previously studied in broccoli and other vegetables.