If you want to get the most nutrients from a salad, take the advice of researchers who have found that what you put on your salad is as important as what’s in your salad.
A study at Purdue shows that olive oil on a salad helps your body absorb more beneficial phytonutrients than other oils make possible. Fat-free salad dressings are the least helpful.
The human body needs fat in the digestive system to be able to absorb natural chemicals like carotenoids from vegetarian foods. The carotenoids, which include lutein, lycopene, beta-carotene and zeaxanthin, have been shown to reduce risk of chronic and degenerative diseases like heart disease, skin cancer and macular degeneration
“If you want to utilize more from your fruits and vegetables, you have to pair them correctly with fat-based dressings,” says researcher Mario Ferruzzi, a Purdue associate professor of food science. “If you have a salad with a fat-free dressing, there is a reduction in calories, but you lose some of the benefits of the vegetables.”
The study showed that polyunsaturated oils like soybean oil are “dose dependent.” The more oil on the salad, the more carotenoids people absorb. A saturated fat like butter was also dose-dependent, but to a lesser extent.
Monounsaturated fat-rich dressings, such olive oil-based dressings, promoted optimal absorption of health-promoting carotenoids from fresh vegetables. The scientists found that you only need a smidgen of olive oil on a salad to promote efficient assimilation of carotenoids.