Eat fat to become lean…
“One measure for a dog, two for a man?” Iams and other dog food or supplement makers were adocating MCT from coconut and palm oil for their sponsored sled dog teams back in the early 90s. There was a Mayo Clinic diet promoted for weight loss before that, a type of ketogenic diet. David Kronfeld was talking about the benefits of ketone bodies for sled dogs long before too.
To the extent that ketones aka ketone bodies are comparable from exercise, low glycemic diets, fasting and MCT dietary sources, you could say that coconut oil is exercise or fasting without exercising or fasting. Gain without pain. Although many people who have fasted will tell you that fasting is not so hard after the first 24 hours, they feel empowered, invested and committed so that stopping a fast is harder than continuing.
Excerpts from an article in AOCS magazine Inform:
Coconut is the oil du jour, attracting endorsements from athletes and celebrities for its alleged health-promoting effects. The oil, once considered exotic outside of the tropics, is showing up in supermarkets and health food stores everywhere, often advertised as a “functional food.” Yet not long ago, coconut oil was reviled by health experts, lumped in the same unhealthful category as lard and tallow because of its high content of saturated fat. As saturated fat has embarked on the long road to exoneration, many people are starting to appreciate the unique physical and chemical characteristics of coconut oil, not only as a cooking oil, but also as a cosmetic ingredient, an antimicrobial agent, a biofuel, and even a possible medicine for ailments ranging from obesity to Alzheimer’s disease. But does the scientific evidence of coconut oil’s benefits justify the hype?
Based mainly on incomplete epidemiological data, in the 1950s prominent US nutrition researcher Ancel Keys formulated a hypothesis that dietary saturated fat raises cholesterol levels in the blood, which in turn clogs arteries and causes heart disease. Because coconut oil is about 93% saturated fat, it was viewed as less healthful than edible oils composed of primarily unsaturated fats, such as soybean oil.
Apparently bolstering Keys’ hypothesis, several studies showed that rodents fed coconut oil as the sole dietary fat had higher cholesterol levels and were much less healthy than animals fed corn or soybean oil (e.g., Williams, M. A., et al., J. Nutr., 1972). However, according to Foale, these studies were flawed because coconut oil lacks the essential omega-3 fatty acids. Therefore, the animals fed coconut oil were suffering from a dietary deficiency, rather than from negative effects of the oil per se. “In the real world, coconut users of the tropics generally eat fish, which are rich in omega-3 fatty acids,” says Foale. “So the combination has always been a healthy one, and heart disease isn’t an issue among traditional coconut users.” Moreover, in these studies the researchers typically used hydrogenated coconut oil, which could contain trans fats. Trans fats are now recognized to have adverse effects on serum cholesterol levels and human health.
Despite firmly entrenched biases against saturated fat within the medical community, mounting evidence has begun to exonerate saturated fat as a contributing factor to heart disease. Coconut oil has likely benefited from this recent development. Like other saturated fats, coconut oil raises the total serum cholesterol level, which concerns some health experts. However, more than any other type of fat, saturated fats raise the level of high-density lipoprotein (HDL) cholesterol, the so-called “good” cholesterol that has been correlated with a reduced risk of heart disease (Cassiday, L., Inform, 2015). Although saturated fat also raises the serum level of low-density lipoprotein (LDL), or “bad,” cholesterol, the type of LDL particles increased are of the large, buoyant type, which are less strongly associated with cardiovascular disease than small, dense LDL particles.
Because of the opposing effects of HDL and LDL cholesterol, the total serum cholesterol level has proven to be a poor predictor of cardiovascular risk. Instead, the ratio of total cholesterol to HDL cholesterol (total:HDL) is a more reliable estimate, with lower levels correlating with reduced risk. Whereas unsaturated fats lower total:HDL cholesterol, and trans fats raise the ratio, saturated fats typically have no effect, suggesting a neutral influence on heart disease risk.
A DIFFERENT SATURATED FAT
Although saturated fats are often considered a single nutritional entity, studies have shown that molecular chain length greatly influences a fatty acid’s metabolic and physiologic properties. Coconut oil is unique in its fatty acid composition, containing more than 65% medium-chain fatty acids (MCFAs)—commonly defined as fatty acids with chains of 6 to 12 carbon atoms (C6–C12) (Fig. 2). In contrast, saturated fats in animal fats and most other vegetable oils are mainly long-chain fatty acids (LCFAs), which contain 14 to 18 carbon atoms (C14–C18). Triacylglycerides (TAGs) composed of MCFAs are more water-soluble and readily digestible than TAGs containing LCFAs.
Coconut and palm kernel oils have similar fatty acid profiles, but they have different triacylglyceride (TAG) compositions (Dayrit, F. M.,http://doi.org/10.1007/s11746-014-2562-7, 2015). In one study, researchers found that the predominant TAGs in coconut oil are trilaurin (3C12), 1-capro,2,3-dilauryl glyceride (C10-C12-C12), and 1-capro,2-lauryl,3-myristyl glyceride (C10-C12-C14). In contrast, palm kernel oil contains mostly trilaurin (3C12), 1-myristyl,2-stearyl,3-lauryl glyceride (C14-C18-C12), and 1,3-oleyl,2-lauryl glyceride (C18:1-C12-C18:1). Unlike coconut oil, palm kernel oil is not commonly consumed in the diet because of the presence of residual extraction solvents, says Foale.
“Most of the health benefits of coconut oil, whether VCO or RBD coconut oil, have been attributed to the high content of lauric acid,” says Fabian M. Dayrit, professor of chemistry at Ateneo de Manila University, in Quezon City, Philippines. “Additional health benefits of VCO have been attributed to the presence of polyphenols.”
As a result, most ingested MCFAs are transported directly to the liver, where they are converted to energy and other metabolites rather than being stored as fat. Indeed, among fatty acids, lauric acid contributes the least to fat accumulation.
Upon arrival at the liver, MCFAs enter the mitochondria. Unlike LCFAs, MCFAs can freely diffuse across the mitochondrial membrane without requiring carnitine-assisted transport. MCFAs are then rapidly metabolized by one of two pathways (Fig. 5). The major pathway, β-oxidation, yields acetyl CoA. Acetyl CoA either enters the citric acid cycle to produce energy, or is further metabolized to ketone bodies. Ketone bodies are three water-soluble molecules (acetoacetate, β-hydroxybutyrate, and acetone) that are transported from the liver to other tissues, such as the brain, muscle, and heart. There, enzymes can convert the ketone bodies to acetyl CoA for use as an energy source. The second pathway, ω-oxidation, accounts for only 10–20% of total liver fatty acid oxidation under normal conditions. This pathway produces 11- and 12-hydroxyl fatty acids, which can be further oxidized to dicarboxylic acids The ω-oxidation pathway may help remove excess fatty acids from the mitochondrial respiratory chain (Dayrit, F. M., Philipp. J. Sci., 2014).
Because of their rapid metabolism in the liver, MCFAs do not contribute to fat accumulation or obesity nearly as much as other dietary fatty acids.
Foale notes that many health-conscious people are now incorporating coconut oil into their diets, whether as a cooking oil or as an addition to their morning cereal, smoothies, or desserts. “People who are a bit skeptical about the advice that ‘this is a saturated fat and it’s bad for you’ are prepared to try it,” says Foale. “And then they discover that they feel better with it: Their general well-being is improved, and they feel more energetic.” Many athletes find that coconut oil sustains their energy during exhaustive competitions, Foale says, possibly due to the ketone bodies formed from MCFAs. Ketone bodies can serve as an alternative energy source in muscles during strenuous exercise, when glucose reserves may be lagging.
Although experimental evidence is lacking, some researchers have theorized that the ketone bodies generated from MCFAs in coconut oil could help treat neurological disorders such as Alzheimer’s disease. Scientists have already established that a ketogenic diet—a high-fat, low-carbohydrate, adequate-protein eating plan—can drastically reduce the rate of seizures in epileptic children who are resistant to drug therapies (Watkins, C.,Inform, 2016). The lack of carbohydrates in the ketogenic diet forces the liver to convert fat into ketone bodies, which can cross the blood-brain barrier and be used as a source of energy by the brain. However, the mechanism by which ketone bodies can help prevent epileptic seizures in some patients is still unknown.
In Alzheimer’s disease, certain parts of the brain have an impaired ability to use glucose, partially due to disruption of insulin signaling. Thus, ketone bodies may help alleviate symptoms of Alzheimer’s by providing an alternative energy source for the brain. Researchers have also proposed that polyphenols and plant hormones called cytokinins in VCO may prevent aggregation of amyloid-β, the peptide that forms plaques in the brains of people with Alzheimer’s disease. Antioxidants such as polyphenols also scavenge free radicals that cause oxidative stress, a condition that has been linked to Alzheimer’s disease.
“I confess to some frustration that a food oil that has supported traditional healthy diets for millennia must now be proven to support good health because it was maligned and ousted from acceptance in the diet policies of the U.S. and Australia, in particular,” says Foale.