A study at Ohio State University found that many of the nutrients that make salad so healthful are fat soluble, meaning that they must be eaten with some kind of fat in order to be absorbed.
“If you don’t have some fat in the meal, all these wonderful” compounds are missed, Steven Clinton, program leader for molecular carcinogenesis and chemoprevention and the Ohio State University Comprehensive Cancer Center in Columbus told the The Wall Street Journal. “If the nutrients don’t get into your system, then what good are they?”
Thus, adding olive oil, avocado, or other fatty foods to your salad makes it healthier.
But the kind of fat you consume matters. Trans fats, such as those found in margarine and processed foods, actually slow the absorption of vitamins, a recent German study found.
For optimum nutrient absorption from salad, add about two tablespoons of canola oil.
Nutritionists caution diners not to go overboard. They suggest choosing just one item per meal that is high in fat while keeping other foods in the meal very low in fat.