From a health standpoint, it’s tough to beat a vegetable-packed salad. But you may need to top it with enough of a fat-based dressing to get more of the vegetables’ healthy fat-soluble compounds, suggests a new study.
The study focused on a handful of the fat-soluble carotenoids, such as lycopene, lutein, and zeaxanthin. Lab studies show these compounds have antioxidant and anti-inflammatory properties. And AICR’s expert report and its updates show that eating foods containing carotenoids lowers the risk of mouth, pharynx, and lung cancers.
The study was published online in the journal Molecular Nutrition & Food Research.
In the study, 29 people ate salads topped with three dressings high in different fats: monounsaturated, polyunsaturated, and saturated. The dressings for each fat were canola oil, soybean oil, and butter, respectively. Salads were served with varying amounts of each dressing to represent low-fat (3 grams), moderate (8 grams), and high fat (20 grams). A tablespoon of oil is 14 grams.
The salad-eaters even scooped their salad bowl clean with a piece of bread to make sure they ate every drop of dressing. Researchers then measured carotenoid levels in the blood.
When looking at all the fats together, eating 20 grams led to absorbing more carotenoids than the moderate or low amounts. The type of fat had less effect on carotenoid absorption. The results on the differences between fat types were not significant but there were trends.
The findings suggested that the monounsaturated, canola dressing promoted the highest absorption of carotenoids, followed by the polyunsaturated and then the saturated dressings. Also, carotenoid absorption was similar whether eating 3 grams or 20 grams of the monounsaturated canola-oil.
Looking at meal patterns is also important to understand carotenoid absorption. Previous studies have found that our cells may store carotenoids until we eat enough fats to make them available, the authors write.
For now, as to what this means for salad lovers and people watching their weight, it all depends upon what else you’re eating, says Alice Bender, AICR’s Registered Dietitian. If you’re eating a salad with other high-fat foods, like nuts or cheese, you may not want to include as much dressing. If you’re just having a vegetable salad, it seems you’ll be better off adding at least low-fat or regular-fat salad dressings.