In reading more about how freaking fantastic nutritional ketosis is for you, it’s clear that fats are really good. There’s some disagreement in which fats are better for you, though, so I did some digging.
Specifically, I wasn’t sure if purified medium chain triglycerides (MCT) like those found in MCT oil or Brain Octane (100% 8 carbon chain fatty acids, also called Caprylic or octanoic acid) were better than the naturally occurring balance of 9% caprylic acid, 10% decanoic acid (10C fatty acids), 52% lauric acid (12C), and ~38% longer chains (14C, 16C, and 18C).
Fatty acids are just COOH (that’s carbon bonded to two oxygen atoms, one of which is bonded to hydrogen; also called carboxylic acid) bonded to long chains of carbon. Plant and animal cells can burn them for energy, just like how you can burn a log for heat. Triglycerides (three fatty acids bonded together with a glycerol backbone) are how fatty acids are stored for later in your liver and fat cells. Medium Chain Triglyceride, then, means a triglyceride with three medium-length (6-12) carbon chain fatty acids.
I’d initially read the bulletproof coffee guy, Dave Asprey, on why pure caprylic acid (the stuff he sells as “brain octane”) was better:
The problem is that studies show you can’t get enough of the really useful MCTs from just eating coconut oil or a so-called “MCT oil” that is diluted with lauric acid, a useful, but cheap, and hugely abundant part of coconut oil that is marketed as an MCT oil (What is MCT oil vs. Coconut oil? via Medium Chain Triglycerides (MCTs))
But wikipedia says:
Lauric acid, a 12-carbon chain fatty acid, is often removed [from coconut oil] because of its high value for industrial and medical purposes. (Coconut oil via Fatty Acids and Derivatives from Coconut Oil)
So that doesn’t quite line up Mr. Asprey.
Wikipedia also says lauric acid is probably good for you:
Lauric acid increases total serum cholesterol more than many other fatty acids. But most of the increase is attributable to an increase in high-density lipoprotein (HDL) (the “good” blood cholesterol). As a result, lauric acid has been characterized as having “a more favorable effect on total HDL cholesterol than any other fatty acid [examined], either saturated or unsaturated”. (Lauric Acid)
Lauric acid might also have antimicrobial properties.
And this random site I found makes the naturalistic argument that whole coconut oil is probably better than refined stuff:
Is MCT Oil better than Coconut Oil? No, of course not. How can a product that has the most famous and most dominant fatty acid removed from the original product be considered “better”? (MCT Oil vs. Coconut Oil: The Truth Exposed)
Which is backed up by some data:
Multiple studies on Pacific Island populations, who get 30-60% of their total caloric intact from fully saturated coconut oil, have all shown nearly non-existent rates of cardiovascular disease (Coconut oil consumption and coronary heart disease)
The question here is really “is lauric acid good for you” and I think the answer is definitely yes.
However, lauric acid probably doesn’t result in as much of a blood ketone boost as C10 MCT:
At 1 h, blood 3HB concentrations due to C8 triglyceride were higher than C9 or C10 (503 versus 174 and 225 μmol/L respectively). As MCT chain length increased from C8 to C10, blood concentration of [hydroxybutyrate (a ketone)] decreased (Blood D-(-)-3-hydroxybutyrate concentrations after oral administration of trioctanoin, trinonanoin, or tridecanoin to newborn rhesus monkeys)
So if you’re trying to boost blood ketone levels, pure C8 will probably be more effective than coconut oil. I think this means that it’s metabolized more effectively.
I think it’s also clear that LCTs (16-18C found in vegetable or seed oils) are probably worse for you than MCTs (8-10C):
Available lipid emulsions made from soybean or safflower oil are classified as long-chain triglycerides (LCT). In contrast, medium-chain triglyceride (MCT) emulsions have different physical properties and are metabolized by other biochemical pathways…Muscle utilization was significantly improved with MCT administration. There was also a trend toward improved nitrogen balance in the MCT group, and less weight loss in the postoperative period also was observed in this group. During the fat clearance test, the serum ketone concentrations were significantly higher in the MCT than the LCT group. The improvement in nitrogen retention may be associated with increasing ketone and insulin levels. Fat emulsions containing 50% MCT are safe for use in parenteral nutrition and may provide an alternate fuel that improves protein metabolism. (A comparison of medium-chain and long-chain triglycerides in surgical patients..
My general philosophy in nutrition is to start with the assumption that I don’t know anything, and nobody else does either. All of this data doesn’t prove anything one way or another, we just get hints of what’s probably better or worse for us in the long run.
To that end, based on the limited information I have, I think it’s safe to say that regular coconut oil is super good for you, and that purified MCT oil is probably a fad but does help in raising blood ketone levels and therefore probably short term energy levels. If I had to pick one, I’d wager you’d get more long-term benefit from consuming just coconut oil than just MCT oil.