BYOL: December 2012

At a dinner party I recently hosted, a good friend of mine and I started talking about coconut oil. Like me, he eschews all oils and other high-fat, highly processed foods, believing that a diet consisting of 75-80% carbohydrate, 10-15% protein, and only 10% fat to be the ideal diet combination of macro nutrients.

Basically, my friend was arguing that coconut oil, which is 100% fat, has a large amount of saturated fat and doesn’t even have the trace minerals and nutrients found in olive oil and other plant-based oils. As such, he was wondering where people got the idea that coconut oil was a “good” oil.

The Pros:

My friend was right; coconut oil is devoid of even trace amounts of vitamins and minerals (for those keeping score, I guess you can count that as a point for olive oil, but honestly we are talking about such small amounts that its really negligible). Rather, the reason so many people think coconut oil is a beneficial oil is because of the fatty acids it contains- in particular, medium-chain triglycerides (MCT), a type of saturated fat. The MCTs make coconut oil unique because nearly all other oils (animal or plant-based) are comprised of long-chain triglycerides (LCT). MCTs are broken down almost immediately by enzymes in the saliva and gastric juices so that pancreatic fat-digesting enzymes are not even required to complete the digestive process. In the digestive system MCTs are broken down into individual fatty acids. Unlike other fatty acids, these individual acids are absorbed directly from the intestines and sent straight to the liver where they are, (for the most part) burned as fuel, much like a carbohydrate. In this respect they act more like carbohydrates than like fats.

Other fats require pancreatic enzymes to break them into smaller units. They are then absorbed into the intestinal wall and packaged into bundles of fat (lipid) and protein called lipoproteins. These lipoproteins are carried by the lymphatic system, bypassing the liver, and then dumped into the bloodstream, where they are circulated throughout the body. As they circulate in the blood, their fatty components are distributed to all the tissues of the body. The lipoproteins get smaller and smaller, until there is little left of them. At this time they are picked up by the liver, broken apart, and used to produce energy or, if needed, repackaged into other lipoproteins and sent back into the bloodstream to be distributed throughout the body. Because of the difference between the two processes, coconut oil companies are able to market their product as an energy food and even claim it doesn’t contribute to body fat the way other oils do.

The fact that MCTs digest immediately to produce energy and stimulate metabolism has led athletes to use them as a means to enhance exercise performance. Some studies indicate this may be true. In one study, for example, investigators tested the physical endurance of mice that were given MCTs in their daily diet against those that weren't. The study extended over a six-week period. The mice were subjected to a swimming endurance test every other day. They were placed in a pool of water with a constant current. The total swimming time until exhaustion was measured. While at first there was little difference between the groups of mice, those fed MCTs quickly began to out-perform the others and continued to improve throughout the testing period. Tests such as this demonstrated that MCTs had the ability to enhance endurance and exercise performance, at least in mice.

In another study, this one using humans, cyclists pedaled for three hours. During the last hour they were each given a beverage to drink. Those who received beverages containing MCTs reportedly outperformed the others.

The claim is that MCTs provide an energy boost while also boosting the rate of the metabolism. When the metabolism is increased, cells function at a higher rate of efficiency, helping to heal injuries quicker, and replaced old cells faster. Amazingly, because of this, coconut oil companies (a product that is 100% fat) claims their product can actually help people lose weight. Even recognized health experts repeat this claim, as Dr. Oz told his followers, "The first of the health benefits of coconuts—the one you're going to care about a lot—is weight loss."

The Cons:

Others argue that instead of focusing in on the “trees” or the MCTs that are found in coconut oil, we need to step back and view the “forest” or the fact that coconut oil is one of the highest sources of saturated fat. Nearly 92 percent of its fat is saturated. For comparison, olive and soybean oils are about 15 percent saturated, while beef fat is about 50 percent saturated and butter is 63 percent saturated. According to the senior nutrionist at The Center for Science in the Public Interest, David Schardt, only Palm Kernel oil has more saturated fat. The consumption of saturated fats can raise cholesterol and increase the risk of heart disease as well as stroke.

David Schardt also tackles the claim that coconut oil will help slim peoples waists. Apparently there has only been one real research study testing if coconut oil could help people lose weight. It didn’t. At the end of the study, both the control and the test groups lost the same amount of weight during the course of four days while cutting their calories and adding exercise to their daily regimen. This is pretty skimpy evidence.

Instead, the claims about losing weight come from a group of small studies where specifically formulated 100% MCT oil was consumed (coconut oil is less than 60%). Even these findings were insignificant.

The research on coconut oil and cholesterol is similarly scarce, but what has been done shows that coconut oil raises HDL cholesterol (good cholesterol) but raises LDL cholesterol (bad cholesterol) as well, which can increase the chances of cardiovascular disease. As Dr. Esselstyne, of the Cleveland Clinic notes, HDL cholesterol only rises in the presence of LDL cholesterol and a lower overall cholesterol is always preferred.

To further dismiss the marketing advertisements of coconut oil, nutritionist Jeff Novick suggests examining the nutrient density of coconut oil. The nutrient density of any food is defined as a ratio of nutrient content (in grams) to the total energy content (in calories). After running the numbers, Novick notes that 100 calories of coconut oil contains almost no protein, vitamins, minerals, or fiber- adding almost no nutritional value while only 4 teaspoons surpasses the American Heart Association’s recommended daily intake of saturated fat. Coconut oil is high in calories and fat while giving no nutrients in return. As such, Novick concludes that coconut oil is the opposite of a nutrient dense food. Finally, when compared to the nutrient density of sugar, coconut oil actually fared worse.

In addition, Jeff Novick adds that another recent study looked at the effects of even just one high fat meal on HDL, inflammation, and blood flow. Subjects were fed a meal high in calories from coconut oil and the effects were evaluated at 3 and 6 hours after the meal. The meal containing coconut oil impaired the anti-inflammatory action of HDL at both 3 and 6 hours. In addition, blood flow was significantly reduced 3 hours after the meal containing coconut oil and remained slightly reduced at 6 hours. If these studies are correct, (and there is no reason not to trust them,) consuming coconut oil would actually hinder athletic performance.

He also adds that while MCTs do have some benefits, only a small portion of the fats in coconuts are in the form of MCTs but adds that many times, the MCTs are actually removed from the coconut to be used in the medical or cosmetic industry before being turned into coconut oil.

While ultimately the decision to consume coconut oil remains a completely personal choice, it seems like optimal health can only be achieved with minimal to no coconut oil. The small benefits that could possibly be gained from consuming MCTs do not seem worth the long-term health risks.

So perhaps a good New Year resolution is to forget the hyperbole of the coconut oil marketing, and kick coconut oil to the curb.

Hope you all had a wonderful holiday.

Pages

Wednesday, December 26, 2012

Pros and Cons of Coconut Oil

Friday, December 21, 2012

Peanut Butter and Oat Cookies