Does the Timing of your Fruit and Veggie Consumption Matter?

Fresh apples, corn and Swiss chard from the Green City Market

Labor day is the unofficial start of fall and with it comes one of my favorite seasons for fruits and veggies. From apples to pumpkins to sweet corn, fall offers a bounty of delicious fruits and veggies ripe for the picking whether found at your local grocery store, farm stand or my favorite – the Green City Market here in Chicago.

Fruits and Veggies have an Internal Clock

As a dietitian, I’ve often been asked how to make sure you get the most from your produce. You may know that an orange loses it’s vitamin C content over time. What if you could boost the beneficial compounds in your fruits and veggies simply by simulating the light-dark cycle? Circadian rhythms, or our internal clock, are found not only in humans, but in fruits and vegetables as well. And a new study, published in Current Biology, found that there may be a way to boost some of the beneficial compounds in plants by simulating the light-dark cycle after crops are harvested.

As our veggies go from the field to the store or market and then ultimately to our homes, levels of some of the important compounds–like glucosinolates found in cruciferous vegetables (i.e., cabbage)–are lost. Researchers at Rice University studied the effect of the light-dark circle on fruits and vegetables, simulating conditions found in the field and post-harvest. They found that even after harvest, levels of beneficial compounds seemed to peak at certain points in the day.

In the field, plants use circadian rhythms to know when to release certain innate chemicals to fend off pests or to cope with environmental stress like heat or drought—often peaking in the afternoon. What’s significant is that these researchers actually found that levels of beneficial compounds continued to peak even after being picked.

Is it time for a Fruit and Veggie Happy Hour?

While more research is needed – this study suggests we may be able to maximize the nutritional profile of many of the fruits and vegetables we eat. How? You or your favorite produce vendor might consider storing your fruits and veggies under a light-dark cycle. Or you might time your produce consumption for the afternoon hours.

Enjoy the fruits (and veggies) of fall!


[This post has been adapted from a post I originally wrote for the Chicago Dietetic Association, found here:

Chicago Runs: Local Running Resources to Help you get to the Finish Line

Chicago Endurance Sports Runners the Soldier Field 10-miler
Chicago Endurance Sports Runners Just Before the Soldier Field 10-miler

Whether you are looking to run your first 5k or you are training for a marathon, Chicago offers a variety of different running groups and organizations to help you get race-day ready. Not sure if group running is for you? Consider this: research has shown that when you run with or are committed to an exercise plan where others are involved, you tend to give more effort than if you were training alone.

Running partners offer accountability. Here’s an overview of some of the groups and running stores that offer fun runs and training programs here in Chicago.

Chicago Area Runners Association (CARA)
Easily the largest organization, 30-year-old CARA is 9,000 members strong. Go to for training programs and meeting spots.

Chicago Endurance Sports (CES)
My personal favorite (I’m training with CES for the Chicago marathon this fall), this group caters to beginners looking to run their first long distance race to more experienced athletes. Check out for training programs and upcoming races.

Universal Sole
Universal Sole is a store in Lincoln Park that offers fun runs on Monday nights at 6:15pm (3052 N Lincoln Ave). For more, visit:

Fleet Feet
With locations in Lincoln Square, Old Town and soon-to-open in the South Loop, Fleet Feet is the source for all things running related and they offer a number of fun runs and training groups that meet any runners needs. Stop by one of their stores and speak to a knowledgeable employee or visit

(This article first appeared in the Chicago Academy of Nutrition & Dietetics Summer 2013 Newsletter, available here: