With the excessive use of pesticides and herbicides in commercial agriculture, we might forget that plants actually have their own methods for protecting themselves against pests and harsh environmental stressors. While the protections of our domesticated species may not be as potent as those of their wild ancestors, how else could these plants have survived to see the day they would be coddled by our industrial methods in a sunny California field?
Compounds like resveratrol in grapes, lycopene in tomatoes, anthocyanins in blueberries, sulforophane and glucosinolates in broccoli and other brassica vegetables… they are sun-protecting pigments, insect poisons or off-putting bitter flavors that we’re beginning to realize may have strong antioxidant, anti-cancer and disease-fighting benefits in humans.
In turn, maximizing the concentrations of these compounds in our vegetables would likely be a good thing for human health.
A recent study out of the journal Current Biology aimed to take advantage of this idea. Turns out, plant circadian rhythms (the same as in humans responsible for jet lag) influence production of these protective compounds. The study authors showed in previous research that a certain plant species ramped up synthesis of insect-fighting chemicals shortly before sunrise when insects commonly feed. In this study, researchers showed that they could manipulate circadian rhythms of already harvested fruits and vegetables (cabbage, spinach, lettuce, zucchini, carrots, sweet potatoes and blueberries) using controlled light-dark cycles that mimic day and night. In the cabbage, this technique enabled them to deliberately increase production of a well-known anti-cancer compound.
Basically, we may be able to influence a vegetable’s natural defenses in order to enhance the health benefit that it provides. Currently our produce lives in the dark at the bottom of the refrigerator all but maybe 5 minutes per day that we have the door open. If we bring some light to the vegetable drawer, maybe we can keep our greens livelier for longer.
Can you imagine your next refrigerator with a sunrise cycle? Tell it what time you plan to eat dinner to ensure that your vegetables are armed and ready.