The Healthiest Dressing for Your Salad

You might think you're doing your body a favor by going for fat-free salad dressing, but according to a new study, your heart will thank you for a little fat with those veggies!

The study, from Purdue University, published in the journal Molecular Nutrition & Food Research, compared the benefits of eating salads along with saturated, monounsaturated and polyunsaturated fat-based dressings.

Wait -- no fat-free dressing? That's right. Mario Ferruzzi, the study's lead author and a Purdue associate professor of food science, explains to HealthySELF that it's important to eat some fat along with your veggies so that your body can more efficiently absorb the carotenoids in the vegetables. Carotenoids are compounds such as lutein, lycopene and beta-carotene, which may help protect you from many chronic and degenerative diseases such as cancer and heart disease.

This study, Ferruzzi explains, was designed to figure out which type of fat -- and how much of it -- is most beneficial to eat along with your greens, especially since he sees a trend toward eating salads as a full meal. Ferruzzi and his team fed 29 people salads dressed with butter as a saturated fat, canola oil as a monounsaturated fat and corn oil as a polyunsaturated fat. Each salad was served with three grams, eight grams or 20 grams of fat from dressing.

According to the study results, with polyunsaturated fat (like corn oil), the more you eat, the greater the benefits in terms of carotenoid absorption. The same is true, to a somewhat lesser extent, with saturated fat (like a butter-based dressing) -- meaning both polyunsaturated and saturated fats are "dose-dependent," and you have to eat more of them to get more out of the veggies. But with monounsaturated fat-rich dressings, such as canola and olive oil-based dressings, you get the same benefits eating only three grams of fat as you do with 20 grams!

Therefore, explains Ferruzzi, a salad dressing containing olive oil, canola oil or another monounsaturated fat is ideal, because you'll get all the heart-healthy benefits of the veggies without going overboard with fat.

"We love that this study and others have been helping to get the message out about the importance of using some fat on salads," say SELF contributing editors Stephanie Clarke and Willow Jarosh, registered dietitians and co-founders of C&J Nutrition.

"It's also important [that including fat in your dressing] ensures that if a salad is being eaten as a meal, that it's high enough in calories to be satisfying as such," say Clarke and Jarosh. "Of course," they add, "portions of fats still need to be controlled, so that you get enough fat, but not too much to push the calories of the salad over an appropriate amount."

So, what's the BEST kind of salad dressing?

"The ideal is to mix up your own so that you can choose the oil that you use, and skip added preservatives and sugars," say Clarke and Jarosh. "An oil and vinegar combo is the simplest to make at home. Vinegars such as balsamic, red wine and white wine are all great staples to have on hand to mix with olive oil or canola oil. Then, add a little more flavor by whisking in chopped garlic or shallots, citrus juice, other herbs and spices and a touch of honey if you'd like to tame the acidity of the vinegar."

Want something creamy in your salad? "Avocado is another great way to add fat to a salad, specially if you crave the creaminess that you would typically get from creamy dressings," say Clarke and Jarosh. "Avocado contains monounsaturated fats, as do nuts and seeds -- another great salad addition!"

What about your other favorite dressings? Clarke and Jarosh break some of them down for you here:

Blue cheese. "Blue cheese contains mostly saturated fat, which will help with nutrient absorption to an extent," say Clarke and Jarosh. But it is dose-dependent, meaning you have to eat more of the dressing to absorb more of the carotenoids, so you have to balance that against the ramifications of eating too much saturated fat.

Ranch. "Most brands of Ranch use soybean oil as the main fat, so this wouldn't be ideal because soybean oil is primarily polyunsaturated," say Clarke and Jarosh. "But again, it will still help with nutrient absorption."

"Low-fat" dressings. "Not worth it," say Clarke and Jarosh. "They usually have fillers and more added sugar in order to keep the flavor up without the fat." Better to go for a full-fat vinaigrette dressing that uses olive oil or canola oil for its main oil (meaning that oil should be first on the ingredient list in the dressing), they recommend.