Salad vegetables are chock full of important vitamins and nutirents. But according to a Purdue University study you won’t get much benefit without the right type and amount of salad dressing. So, in this study one of the targets for us was basically to look at salad vegetables as a primary source of carotenoids in the daily diet of Americans. For our bodies to be able to absorb and utilize these nutrients, we need fat to help solubilize them and extract them from foods as they are being digested, and also to help with the natural process of fat absorption in the body which carries these fat soluble phytochemicals in.
Carotenoids are compounds in nature that are believed to have health benefits beyond basic nutritional value. These benefits include lowering risks of several chronic and degenerative diseases, including: cancer, cardiovascular disease and macular degeneration. Salad vegetables is one of the main classes of vegetables which Americans seem to consume pretty regularly. This includes tomatoes, carrots, lettuce, spinach, fresh spinach. Our reason for using that was the fact that in some cases people will actually replace meals, especially lunch for example, with a salad.
Researchers fed subjects salads topped off with saturated, mono-unsaturated and poly-unsaturated fat based dressings. Then tested their blood for absorption of these fat soluble carotenoids. These vegetable oil based dressings were chosen primarily because their common use in salad dressings. This being canola oil and soybean oil. Then we wanted to compare these vegetable oils to more saturated fat source such as butter. Our big question was not just related to how does fat influence absorption of carotenoids from these vegetables. Our question related more to the need to understand is there a logic to selection of a type and/or an amount of fat that’s going to be, let’s say optimal in the delivery of these carotenoids.
What’s the best choice to make if you are a consumer or a food processer. So our primary findings were that in almost all instances amount was more critical to driving carotenoid absorption, amount of fat was more critical to driving carotenoid absorption than type. Fat soluble, health promoting carotenoids from widely consumed salad vegetables require fat for absorption. So you need to make sure that you have some fat in your salad dressing when you’re choosing healthy. Some fat is healthy. If you feel like choosing a heart healthy oil, such as canola oil or poly-unstaturated rich soybean oil over saturated fat you’ll get the same if not slighty better absorption depending on the individual carotenoids that are in the salad that you are consuming.
It appears there’s priliminary evidence that suggests that low levels of heart healthy canola oil, mono-unsaturated rich, fatty acid rich canola oil, could be as potent as a facilitator for carotenoid absorbtion as higher levels of fat overall..