Once again, everything you know about food and nutrition is false. Not only are you wasting the best bits of your avocados, and being tricked by mischievous coconut oil, but you’re also eating salad incorrectly.
According to a new study led by researchers at Iowa State University, if you’ve been munching on some salad without using any of the salad dressing, you’re probably getting nowhere near as much nutrients out of the meal as you otherwise would have. Yes, plenty of dressings are fairly calorific, but without them, seven different micronutrients are going to waste.
Writing in the American Journal of Clinical Nutrition, the researchers explain how they recruited 12 college-age women – a small sample size, to be fair – and asked them to consume vegetable salads with various amounts of soybean oil, a common ingredient in salad dressings. They then had their blood tested to check out what kinds of nutrients they did or did not absorb from the leafy micro-gardens before them.
They found that the more oil that the salad was coated in, the more nutrients the body ultimately absorbed. In particular, four carotenoids, two forms of vitamin E and vitamin K, and vitamin A were all preferentially absorbed into the body more often than not.
Together, these have a wide range of biological benefits, including healthy skin, preserved eyesight, immune system strength, maintaining your bone strength, and even helping to protect you from cancer.
Maximum nutrient absorption seemed to take place when 32 grams (about 1.1 ounces) of oil was used – about two tablespoons. This was the highest volume of oil tested, so the upper limit could yet be greater than this. There was some variability in the study participants, but overall, it seems that the US dietary recommendation of two tablespoons of such oil per day is a relatively sound one.
Apart from the sample size problem, there are three important caveats to this study. Firstly, the absorption of nutrients, although welcome, is still relatively minor; your life will likely not be changed that drastically if you use more salad dressing these days, but every little helps, as they say.
Secondly, this does not mean you can use as much salad dressing as you like – too much fat in this regard will have a detrimental effect on your health in the long term. Lastly, you can get plenty of these micronutrients from other food sources in arguably healthier ways.
More research will hopefully elucidate on how rigid this so-called “soybean effect” actually is, among both women and men. For now, though, maybe enjoy feeling a little less guilty when you slather your lettuce and spinach leaves in a delicious, glistening oily goop.