Think you're making the right choice by reaching for the low-fat dressing at the salad bar? Think again.
If you want to get the most vitamins and nutrients out of your plate of greens, you need to top them with monounsaturated fat-rich dressing, new research out of Perdue University in the U.S. claims.
If you want to utilize more from your fruits and vegetables, you have to pair them correctly with fat-based dressings," says Mario Ferruzzi, the study's lead author and associate professor of food science, in a press release. "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."
In the study, published online in the journal Molecular Nutrition & Food Research, participants ate salads paired with saturated, monounsaturated and polyunsaturated fat-based dressings. The subjects' blood was then tested for absorption of fat-soluble carotenoids, which are associated with reduced risk of cancer, cardiovascular disease, macular degeneration and other chronic and degenerative diseases.
The researchers found that monounsaturated fat-rich dressings required the least amount of fat to get the most carotenoid absorption, while saturated fat and polyunsaturated fat dressings required higher amounts of fat to get the same benefit.
Monounsaturated fat-rich dressings include canola and olive oil-based dressings. A 3-gram serving promoted the same carotenoid absorption as did a 20-gram serving.
Polyunsaturated dressings, however, like those made from soybean oil, required a larger dose of fat on the salad to absorb more carotenoids.
Overall though, the more fat in the salad dressing the better for absorption of nutrients, regardless of what type of fat is in the dressing.
The Atlantic's Brian Fung summarizes the findings: "The higher fat content of richer dressings actually helps unlock vegetables' nutritional potential as they're being digested."
The research may offend fat phobes, but healthy fats are needed for a salad to reach its nutritional potential.