Enova oil is a new salad and cooking oil from Japan made from a combination of soy and canola oils. The purported advantage of Enova over other polyunsaturated oils is a difference in chemical structure said to help reduce body fat. Most of the fat Enova oil contains is known as diacylglycerol (DAG), which the body processes differently than other fats. While DAG oil is digested and absorbed like other fats, afterwards it appears to go directly to the liver to be burned for energy rather than circulating through the body. Although DAG contains the same number of calories as other types of oil (about 120 per tablespoon), the manufacturer of Enova oil claims that less of it is stored in the body. This is supposed to help with weight control. The promotional materials I've seen claims that Enova oil may actually help you lose weight if you substitute it for conventional oil.
Based on what I've learned about how DAG oils act in the body, if you substitute them for other types of oils used in cooking or for making salad dressings, you might lose a little weight - possibly between three and four pounds - over the course of a year. Claims that Enova oil has a beneficial effect on serum triglyceride levels haven't been borne out by research so far.
While Enova oil may be healthier than polyunsaturated oils, it is not healthier than olive oil. The monounsaturated fats found in olive oil and nuts are the healthiest type of fat of all and the type I recommend that you rely on the most (in addition to omega-3 fatty acids). I always recommend using extra-virgin olive oil. If you don't want too strong a flavor of olive oil in a particular dish, use a good neutral-flavored oil such as expeller-pressed canola oil. Other neutral oils, such as grape seed oil, might be better suited for higher temperature cooking. There are also well-made designer oils that have been altered to have a higher heating point and a more monounsaturated-fat profile, such as the high-oleic versions of safflower and sunflower oil made by Spectrum.
Enova Oil may be a healthier choice than most polyunsaturated oils, which I believe promote cancer, inflammation, damage to the immune system and premature aging. But I still think you're better off with extra-virgin olive oil.
Andrew Weil, M.D.