Eggs atop salads “tops” for boosting carotenoid absorption

Eggs can help, researchers say, at boosting the carotenoid absorption of salads comprised of colorful, mixed, raw vegetables.

Carotenoids are responsible for the red, orange and yellow color of many fruits and vegetables and credited with helping protect against heart disease and cancer by reducing inflammation and oxidative stress.

Purdue University researchers recently released a paper, “Effects of Egg Consumption on Carotenoid Absorption from Co-consumed, Raw Vegetables,” published online in The American Journal of Clinical Nutrition. Carotenoids are fat-soluble nutrients.

A news article on the Purdue University website quoted one of the study coauthors, Wayne Campbell, Ph.D., professor of nutrition science at Purdue. “Eating a salad with a variety of colorful vegetables provides several unique types of carotenoids, including beta-carotene, lutein, zeaxanthin and lycopene,” said Campbell.  “The lipid contained in whole eggs enhances the absorption of all these carotenoids.”

In the study, subjects consumed a salad comprised of tomatoes, shredded carrots, baby spinach, romaine lettuce and Goji berry, either served as vegetables alone, topped with one and a half eggs, or topped with three eggs. Researchers measured a three- to eight-fold increase in carotenoid absorption for salads containing three eggs compared to the salads comprised of vegetables alone. The study used scrambled eggs to ensure participants consumed both the yolk and egg whites.

Carotenoids found in the salads fed to study subjects included beta-carotene, alpha-carotene, lycopene, lutein and zeaxanthin. Egg yolk contains lutein and zeaxanthin and contributed a portion of the carotenoid consumption, while the other three antioxidants are found in vegetables alone.

Researchers stated that most people in the U.S. do not include enough vegetables in their diets and when eating salads often choose fat-free or lower-fat dressings. However, the lipid content of the eggs acted as the agent to enhance carotenoid absorption, increasing the nutritive value of the vegetables.

Tia Rains, Ph.D., senior director, Nutrition Research & Communications at the Egg Nutrition Center commented, “This study shows that eggs can offer consumers one way to include a high-quality, nutrient-rich protein in a plant-based diet.”

The resulting hypothesis is that sustaining a dietary pattern that pairs plant foods with sources of healthy fats at the same meal could lead to greater concentrations of circulating antioxidants. 

2015-11-09 14:48:20