Salad Dressings Can Boost Carotenoids

Those healthy fat-soluble carotenoid compounds in fruits and vegetables need fat for our cells to best absorb them. A new study that looked at types of fat now suggests that topping your salad with enough fat will give you more of the vegetables’ carotenoids.

The study, published online in the journal Molecular Nutrition & Food Research, focused on a handful of carotenoids, including 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.

In the study, 29 people ate salads with three different fat-based dressings. Canola oil was used for the monounsaturated fat; soybean oil for the polyunsaturated; and butter for the saturated fat. Salads were topped with varying amounts of each fat to represent low-fat dressing (3 grams), moderate (8 grams), and high fat (20 grams). A tablespoon of oil is 14 grams. After salad-eaters scooped their bowl clean researchers measured carotenoid levels in their 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 and the differences among fats were not significant. but there were trends.

The canola oil (monounsaturated fat) promoted the highest absorption of carotenoids, followed by the soybean (polyunsaturated fat) and then the butter (saturated fat). Also, carotenoid absorption was similar whether eating 3 grams or 20 grams of the monounsaturated canola-oil. More research is needed looking at how other foods in the meal – and even throughout the day – may affect carotenoid absorption, the authors write.

Source: Goltz, S. R., Campbell, W. W., Chitchumroonchokchai, C., Failla, M. L. and Ferruzzi, M. G. (2012), Meal triacylglycerol profile modulates postprandial absorption of carotenoids in humans. Mol. Nutr. Food Res., 56: 866877.