Don't look now, but your salad is alive and knows the time

Kathleen Blanchard's picture
Vegetables have a Circadian rhythm that continues after harvesting.

Just like humans, vegetables have a Circadian rhythm. Researchers say fruit and vegetables continue to live after they are harvested and so does their biological clock. Your vegetables really can tell time.

Advertisement

Vegetables know the time of day

The finding, published in the journal Current Biology, means those living vegetables at the produce section of your grocery store have waxing and waning nutritional value that can change the health benefits we get when we try to eat plenty of foods with antioxidants.

Janet Braam of Rice University says vegetables respond to light and dark. We also know humans are the same when it comes to Circadian rhythm and sleep-wake cycles that are so important for optimal health.

Advertisement

Braam suggests we might want to store our fruits and vegetables at certain times to get more nutritional bang for our buck. Exposing fruits and vegetables to dark and light cycles could enhance their nutritional value, as could the timing of when we cook and eat them, she explains.

The team of biologists, led by Braam, found out food grown in the lab changes physiologically in response to Circadian rhythm, leading to them to suspect what we grown in the garden or on the farm might do the same thing, even after harvesting.

The researchers explain plant cells, unlike animals or mammals, continue to survive after they are plucked from the earth, vine or tree. Different parts of plants can continue to live independently such as the fruits and branches, meaning they continue to metabolize as their biological clocks keep on working.

Plants alter their phytochemicals in response to light and dark to help protect from being eaten by insects. After fruits and vegetables are picked they continue to perceive light and dark. The advantage to humans related to the finding is that fruits and vegetables could be eaten when phytochemicals are at their peak. Many plants have anti-cancer benefits that are greater at different times of the day, according to the research.

"It may be of interest to harvest crops and freeze or otherwise preserve them at specific times of day, when nutrients and valuable phytochemicals are at their peak," Braam said in a press release. Another suggestion is to rethink the time of day we eat dinner, in keeping with the same schedule as our fruits and vegetables.

Advertisement