Spinach Spotlight

How cooking effects nutrient absorption

National Spinach Day (March 26 this year), has all of us at Dole thinking about all the ways we can use this versatile leafy green.  Any spinach lover will tell you that it can be added to just about anything and tastes fabulous!  From smoothies, to salads, to pesto and meatballs, it can really enhance just about any dish – but is there a method that best delivers its nutritious goodness?

A study published in Food Chemistry reviewed a variety of household cooking methods to see how absorption of lutein, a nutrient in spinach was affected.  Lutein is a carotenoid associated with eye health as well as cognitive quickness, so its something we definitely want to absorb!  Remember, when fruits and vegetables are cooked, nutrients are often lost as a result of exposure to heat.  On the other hand, some nutrients are even better absorbed after cooking because cell walls have been broken down, making it easier for them to be released.  In a lab model, Swedish scientists compared boiling, steaming, pan frying, microwaving and liquefying spinach to see how lutein levels were affected. 

They found that simulating the process of making soup, or boiling spinach, resulted in less than 60% lutein retention when compared to raw spinach leaves.  We suggest adding spinach at the last moment before serving soups or stews to preserve maximal nutrients.  Researchers also tested pan fried spinach and saw that after two minutes there was 60% less lutein when compared to raw leaves, reinforcing the idea that exposure to high temperatures will increase nutrient loss.  When looking at juicing or smoothies however, lutein was observed to be significantly higher by way of 30 to over 150% respectively as compared to raw leaves.  Why so much more?  It’s because when spinach is liquefied, the particles have been made smaller, predigested even, in turn making lutein more easily accessible by the body.  The substantial increase observed in the smoothie is attributed to the presence of dairy which likely enhances lutein uptake in the body.

Bottom line?  To get the most out of your spinach, it may be best to avoid heating it at all.  Try it in a chopped salad or better yet, a smoothie that includes low fat dairy to maximize absorption. 

Published March 1, 2019