best spinach

Hit up a farmer's market to get the best spinach. But at the supermarket, look for spinach sitting under lights for more nutritious greens.

Bright idea: At the supermarket, buy spinach that's been kept under lights.

RODALE NEWS, EMMAUS, PA—When it came to his spinach fetish, Popeye was on the right track, but he just didn't see the light. For the best spinach, he should have selected fresh over canned spinach, specifically greens sold under bright lighting. New research published in the Journal of Agriculture and Food Chemistry found that spinach kept under lights stays fresher longer, and even can keep producing vitamins. "This impacts all consumers who eat fresh leafy greens and fruits by improving the level of human bioactive compounds—vitamins A, C, E, K, and B," explains study author Gene Lester, MS, PhD, plant physiologist with USDA Agricultural Research Service.

THE DETAILS: "This research was conduced as a result of my going to the supermarket and asking the question, 'Is produce exposed to continuous light equal to produce stored in continuous dark?'" Lester says. He and his team found that in just three days, spinach kept under store lights boasted larger amounts of vitamins C, E, K, and folate. It also had higher levels of lutein and zeaxanthin, nutrients that boost eye health. Produce kept under store lights lasted longer, too, compared to spinach that encountered periods of darkness.

WHAT IT MEANS: This doesn't mean you should set up shop lights at home to shine on your spinach. However, healthy food shoppers can use this new research when at the market or supermarket to find spinach that will last longer at home and greens that are packed with the most nutrients. And nutrients aren't the only reason you should invest in spinach. Research has found the superfood can reduce the risk of cataracts, macular degeneration, and even headaches and PMS (researchers found the magnesium in spinach can help alleviate the pain associated with these ailments).

Read on for tips on selecting the best, most nutritious spinach.