If you’re a salad lover and use ready-made dressings, you may have seen the notice on bottles that reads something like: “the oil in this dressing helps your body absorb important nutrients from salads.”

While it is true that vegetables and fruits are full of fat-soluble nutrients like vitamin E and carotenoids that require fats to be absorbed, all fat is not created equal.

Researchers found that among common types of fats/oils used in dressings, monounsaturated fats like those found in canola and olive oil deliver the highest nutrient absorption with the least amount of fat.

Study details

The researchers gave 29 test subjects a salad topped with saturated fat (butter), monounsaturated fat (canola oil) or polyunsaturated fat (soybean oil) -based dressings. Each salad was served with either 3 grams, 8 grams or 20 grams of fat as dressing.

The typical commercial full-fat salad dressing has 10 to 20 grams of fat per serving, while low-fat versions have about 3 grams. Nutrient intake was measured in the study subjects through blood samples.

The researchers found that soybean oil, which is high in polyunsaturated fat, was the most dose dependent. The more soybean oil the subjects consumed the more carotenoids they absorbed. Saturated fat from butter was also dose-dependent, but to a lesser extent.

The monounsaturated fats in canola oil dressings, on the other hand, promoted the same level of carotenoid absorption with a 3 gram serving as a 20 gram serving. So, you can get the same level of absorption with fewer fat grams and calories, making this lipid source a good choice.

So if you are watching your calories and want a low-fat dressing, make sure the dressing includes at least 3 grams of monounsaturated fat from canola or olive oil or you just might miss out on many of the nutrients in your salad.

Source:

WebMd

Whole Foods Market's announcement about taking their first steps toward limiting genetically-modified organisms (GMOs) from their stores in America sounds far more hopeless and unrealistic today than it did a year ago, based on a report from a group of ecologists at the recent 95th meeting of the Ecological Society of America (ESA) in Pittsburgh.

The gist: Despite assurances from the Agri-Business sector, scientists discovered GM yellow canola plants "growing in the middle of nowhere" North Dakota, in places far away from conventional and GM crops, that are resistant to herbicides made by Monsanto (glyphosate) and Bayer Crop Science (gluphosinate) and, in two cases, to both substances.

GM samples of the canola/rapeseed plant (Brassica napus) were found at almost half of the 288 sites scientists investigated along North Dakota roads. Of the roughly 140 sites and 406 plants collected in the state, 347 were genetically modified to resist either pesticide. And, two plant samples showed signs of stacked traits, meaning resistance to both pesticides.

Here's a sobering thought from a University of Arkansas scientist about the evolving genetic makeup of native plants, as told to Scientific American: This is a good model for the influence of agriculture on the evolution of native plants. We can imagine gene flow to native species. If we can imagine that happening, it probably happens.

Evidence for the establishment and persistence of genetically modified canola populations in the U.S (95th ESA Annual Meeting Abstract) August 6, 2010

Discover/80 Beats Blog August 6, 2010

Scientific American.com August 6, 2010

Nature News.com August 6, 2010