Think sugar is the unhealthiest thing you can eat? Think again. According to a recently published paper by scientists at the University of California at Riverside, soybean oil causes more obesity than fructose. Read more about the published findings here. In this study, scientists set up four different diets for male mice, each of which contained about 40% fat (similar to what most humans consume). In the first diet, the saturated fat came from coconut oil. In the second diet, half of the coconut oil was replaced with soybean oil, which contains polyunsaturated fat. This particular diet was on par with the amount of soybean oil Americans currently consume. The other two diets contained added fructose. All four of the diets contained the same amount of calories and all the mice ate the same amount of food.
The scientists assumed that the mice who were given the high fructose diets would develop the most insulin resistance and would pack on the most fat. But that’s not what happened. Interestingly, the mice who ate the soybean oil diet minus the fructose gained the most weight – 9% more than the fructose eating mice and 25% more than the mice who were fed the coconut oil diet. Also, the mice on the soybean oil diet developed fattier livers and more insulin resistance – both indicators of diabetes and metabolic syndrome. “That was a surprise, given that most people think that unsaturated fatty acids [like those found in soybean oil] are supposed to be healthy,” said lead study author Poonamjot Deol, Ph.D., a cell biologist at the University of California, Riverside.
Soybean oil is EVERYWHERE. Half of all the vegetable oil produced in the world is soybean oil. Because it’s so cheap, it’s used in a ton of packaged foods. So what exactly makes soybean oil so horrible? One guess is that it could have something to do with the way it influences genes that determine how the liver metabolizes fat. And other processed vegetable oils aren’t much better. Soybean oil can be difficult to avoid because it’s so prevalent in our food system. If you have a bottle of vegetable oil in your pantry, chances are it’s primarily soybean oil.
So what’s the alternative? Stick to extra virgin olive oil for cooking and coconut oil for baking.