We all know that salad is a healthy option, filled with beneficial vitamins and minerals, but many health conscious eaters who choose low fat salad dressings in a bid to improve their diet might actually be missing out on the benefits of all those lovely nutrients.
A recent study at Purdue University in Indiana has suggested that eating fat is necessary for us to absorb nutrients found in vegetables and salad, and that the type of fat and the amount that we use can play an important role in how much benefit we get from our food. The study was funded by the US Department of Agriculture and was published in Molecular Nutrition and Food Research.
Why Should We Eat Fat With Salad?
The salads and vegetables that we eat contain carotenoids such as lutein, lycopene, beta-carotene and zeaxanthin. Consumption of these carotenoids is associated with a lower risk of common diseases such as cardiovascular disease and cancer, so they are crucial to maintaining good health.
These carotenoid compounds are fat soluble, meaning that if they are eaten alongside fat, they will pass more easily into our blood stream and our bodies can make use of them. Fats can also slow down the digestion process, meaning that our bodies have more time to break down and absorb nutrients from the foods that we eat.
What Did The Study Show?
The study involved 29 participants who were each fed identical salads with different dressings. Their dressings were randomly assigned and they were given three, eight, or twenty grams of:
- Butter – a saturated fat
- Soybean oil – a polyunsaturated fat
- Canola oil – a monounsaturated fat
Each of the participants had their blood tested to check for absorption of carotenoids. The results showed that for butter and soybean oil, the absorption of carotenoids was dose dependent, meaning that the larger the volume of dressing placed on the salad, the more carotenoids were absorbed into the bloodstream of the participant.
The only oil that didnâ€™t seem to be dose dependent was canola oil, which resulted in the same absorption of carotenoids with a three gram dose as it did with a twenty gram dose. However canola oil comes from the genetically modified rapeseed plant and many scientists say it is not safe to consume. This suggests that using monounsaturated extra virgin olive oil is the best way to increase nutrient absorption.
Mario Ferruzzi, the lead author of the study and a professor of food science, stated that,â€œOverall, pairing with fat matters. You can absorb significant amounts of carotenoids with saturated or polyunsaturated fats at low levels, but you would see more carotenoid absorption as you increase the amounts of those fats on a salad.â€
Tips On Using Fat Based Dressings
Raw vegetables and salads are difficult for the body to digest unless you pair them with the right fats, so you might be missing out on some of those essential nutrients if you skimp on salad dressing. Here are some tips on choosing your salad dressing.
- Choose olive oil rather than canola oil or soybean oil, which come from genetically modified plants
- Avoid salad dressings that state they are fat free or low fat
- Look for salad dressings that are low in added sugars
- Make your own dressings with oil, vinegar or lemon juice, and herbs
- Add olive oil or butter to cooked vegetable dishes for better absorption
- Avoid preservatives such as calcium disodium EDTA and additives such as phosphoric acid