Arthur Daniel Midlands has recently launched a new cooking oil in the U.S. that they’re marketing under the name “Enova.” The marketing claim is that “less Enova is stored as fat in your body than other cooking oils.” What is this stuff?
Structure and Process
According to their literature, the key difference between Enova and “conventional” cooking oils is that most plant oils are composed of triglycerides, while Enova is predominantly diglycerides — in particular, diglycerides of a very specific shape. My organic chemistry knowledge is very rusty, but the general idea is that the fats that we ingest are generally (always?) fatty acids attached to glycerol molecules (CH2OH-CHOH-CH2OH).
In triglycerides, all of the OH radicals are replaced by carboxyl groups which attach long hydrocarbon chains. The nature of the fat (both dietarily and physically) varies greatly based on the structure of these chains. Unsaturated fats, for example, have some of their hydrogen atoms replaced by carbon double-bonds. Predictably, diglycerides and monoglycerides replace only two or one such radicals, respectively.
Saturated Fat! It’s What’s For Dinner!
Back to Enova: apparently, the manufacturing process involves starting with traditional (canola, soy) oils, breaking the triglycerides down into glycerol and fatty acids, and then recombining them in the presence of an enzyme. It’s not clear from the literature whether this enzyme catalyzes reattachment to the 1,3 positions or retards attachment to the 2 position of the glycerol — but the net effect is that you end up with mostly 1,3-diglycerides.
Now, the theory is that, since the human body can’t easily reattach fatty acids to the 2 position, processing of these fats after being absorbed is different; instead of being reconstituted and available for deposition as body fat, they are instead used in the liver for beta-oxidation. (Intuitively, it would seem that this would simply make whatever fat would have otherwise been used for that purpose to be deposited in fat stores instead — which, although not particularly useful, would make their marketing claim technically true).
Studies on ingestion of 1,3-digylcerides have produced conflicting results. Findings in Japan indicated that diglycerides may reduce visceral fat more than other areas. This would be significant if true, as recent findings on fat have reinforced earlier observations that viceral fat causes significantly more health problems than fat elsewhere. This study also observed significant fat decrease in subjects’ livers. However, a subsequent study in the U.S. was unable to replicate either result.
Both studies showed that the diglyceride group lost measurably more weight than the control group, so there is probably some benefit there.
In no case has any beneficial impact on blood serum levels of cholesterol or triglycerides been observed. This is particularly interesting, because the reported weight loss alone would generally be expected to cause a measurable decrease in LDL cholesterol levels.
So, the published information sounds pretty good — or, at very worst, innocuous. It’s a bit pricey, and I’m always personally wary of highly synthetic foods (e.g. corn syrup), but it doesn’t seem to have any outright warning signs. That said, there are a couple of items of potential concern that are worth noting.
Looking at it from the perspective of just another vegetable oil, there are some interesting things to note. If you check the nutrition label, you’ll see that it’s lower in saturated fats than even canola oil is. That would generally be good; saturated fats tend to raise LDLs. However, compared to most oils, the polyunsaturated fat content is somewhat high. Polyunsaturated fats tend to drop overall cholesterol levels, both LDL and HDL. That’s not bad, but it certainly isn’t as good as monounsaturates, which tend drop LDLs while raising HDLs. So, from a pure fat profile perspective, this looks like it’s not much of an improvement over, say, canola oil; and it may be worse.
The other interesting thing to take note of is the ratio of omega-6 fatty acids to omega-3 fatty acids. Enova has a ratio of about 10:1, while most vegetable oils are closer to 3:1. Although studies are currently ongoing, some researchers believe that higher percentages of omega-6 may cause higher blood pressure and chronic inflammation. (see http://www.psychosomaticmedicine.org/cgi/content/abstract/69/3/217).
[Edit: cleaned up many typos and cited a relevant study]