If you’re a salad lover and use ready-made dressings, you may have seen the notice on bottles that reads something like: “the oil in this dressing helps your body absorb important nutrients from salads.”
While it is true that vegetables and fruits are full of fat-soluble nutrients like vitamin E and carotenoids that require fats to be absorbed, all fat is not created equal.
Researchers found that among common types of fats/oils used in dressings, monounsaturated fats like those found in canola and olive oil deliver the highest nutrient absorption with the least amount of fat.
The researchers gave 29 test subjects a salad topped with saturated fat (butter), monounsaturated fat (canola oil) or polyunsaturated fat (soybean oil) -based dressings. Each salad was served with either 3 grams, 8 grams or 20 grams of fat as dressing.
The typical commercial full-fat salad dressing has 10 to 20 grams of fat per serving, while low-fat versions have about 3 grams. Nutrient intake was measured in the study subjects through blood samples.
The researchers found that soybean oil, which is high in polyunsaturated fat, was the most dose dependent. The more soybean oil the subjects consumed the more carotenoids they absorbed. Saturated fat from butter was also dose-dependent, but to a lesser extent.
The monounsaturated fats in canola oil dressings, on the other hand, promoted the same level of carotenoid absorption with a 3 gram serving as a 20 gram serving. So, you can get the same level of absorption with fewer fat grams and calories, making this lipid source a good choice.
So if you are watching your calories and want a low-fat dressing, make sure the dressing includes at least 3 grams of monounsaturated fat from canola or olive oil or you just might miss out on many of the nutrients in your salad.