MCTs or Medium Chain Triglycerides
Coconut oil is comprised of what are called medium chain fatty acids, or medium chain triglycerides. These two terms are used interchangeably, and we will refer to them as "MCTs." In nature, coconut oil has the largest concentration of these MCTs outside of human breast milk. Vegetable oils, on the other hand, are made up primarily of long chain fatty acids (LCTs).
It has been known for a long time in the scientific literature that LCTs tend to produce fat in the body, while MCTs promote what is called thermogenesis. Thermogenesis increases the body's metabolism, producing energy. People in the animal feed business have known this truth for quite some time. If you feed animals vegetable oils, they put on weight and produce more fatty meat. If you feed them coconut oil, they will be very lean.
In a study done by Baba, Bracco, and Hashim, for example, and published in the American Journal of Clinical Nutrition, rats were fed MCTs and LCTs for a period of six weeks. At the end of six weeks the rats were killed and dissected, and the total dissectible fat and fat cell size and number were determined. MCT rats gained 15% less weight than LCT controls. Their conclusion: "Overfeeding MCT diet results in decreased body fat related to increased metabolic rate and thermogenesis."
Similar studies have been done on humans. In 1989 a study was done in the Department of Pediatrics, Vanderbilt University, at Nashville TN. Ten male volunteers (ages 22 to 44) were overfed (150% of estimated energy requirement) liquid formula diets containing 40% of fat as either MCT or LCT. Each patient was studied for one week on each diet in a double-blind, crossover design. The results: "Our results demonstrate that excess dietary energy as MCT stimulates thermogenesis to a greater degree than does excess energy as LCT. This increased energy expenditure, most likely due to lipogenesis in the liver, provides evidence that excess energy derived from MCT is stored with a lesser efficiency than is excess energy derived from dietary LCT." Many other studies on the weight-loss aspect of MCTs have been done. For a list of many of these studies, visit www.coconutoil.com and look at the peer-reviewed articles section.
In addition to the weight-loss advantages of MCTs, other studies have shown that MCTs are powerful agents that can kill bacteria, fungus, and viruses. In a study done at the Institute of Biology of the University of Iceland, MCTs were shown to kill gram-positive cocci. Another study done at the University of Iceland showed that two of the MCTs found in coconut oil, capric acid and lauric acid, killed Candida albicans, a common yeast infection found especially in those who have excessively used antibiotic drugs.
Lauric acid is the primary MCT in coconut oil, and numerous studies have demonstrated the anti-viral properties of lauric acid, including the lowering of the viral loads of AIDS patients. One such study was done in the Philippines at San Lorenzo Hospital. See also the research by Dr. Mary Enig.
Saturated fats are probably the most maligned fats in the popular media today. They are often blamed for "clogging arteries" and leading to heart disease. However, an examination of the research and science behind saturated fats leads one to a vastly different conclusion, suggesting that the attacks against saturated fats have been primarily political and economical, and not scientific. While we will provide a brief summary of the science behind saturated fats here, we encourage you to examine the research more closely yourself. Much of it is documented at www.coconutoil.com.
First of all, saturated fats are essential to our health. They comprise about 50% of our cell membranes, and some proportion of saturated fats are found in all fats and oils, whether plant based or animal based.
In recent years some have made claims that too much saturated fats in our diet can lead to higher cholesterol levels and clogged arteries, which leads to heart disease. So an anti-saturated fat campaign was launched in the U.S. in recent years. As a results, Americans have consumed less saturated fats than any other nation, yet the U.S. is still a world leader in deaths from heart disease. Obesity rates are also at an all-time high. Many are now questioning the "wisdom" behind the low-fat nutritional advice that has dominated the popular media (see Gary Taubes article "The Soft Science of Dietary Fat.")
Does research support the claim that saturated fats like coconut oil raise cholesterol levels and clog arteries? Before we look at the research that suggests just the opposite, it should be noted that the "lipid theory" of heart disease, which blames high cholesterol levels as causing heart disease, is seriously being questioned by researchers and doctors. You can read more about the cholesterol issue at www.coconutoil.com
As to the research, a study was done at the Wynn Institute for Metabolic Research, London, examining the composition of human aortic plaques. This study found that the "artery clogging fats" in those who died from heart disease were composed of 26% saturated fat: the rest (74%) were polyunsaturated fatty acids, such as those found in vegetable oils commonly consumed in today's modern societies. Their conclusion: "No associations were found with saturated fatty acids. These findings imply a direct influence of dietary polyunsaturated fatty acids on aortic plaque formation and suggest that current trends favouring increased intake of polyunsaturated fatty acids should be reconsidered."
Another study done at the Department of Nutrition, Harvard School of Public Health. A 14-year study of 43,732 men aged 40-75 years who conducted free from cardiovascular diseases and diabetes in 1986, to see if there was a relationship between dietary fat intake and risk of stroke. They reported that after adjustment for age, smoking, and other potential confounders, no evidence was found that the amount or type of dietary fat affects the risk of developing ischaemic or haemorrhagic stroke. Their conclusion: "These findings do not support associations between intake of total fat, cholesterol, or specific types of fat and risk of stroke in men."
For more information on the science and research associated with saturated fats, visit www.coconutoil.com. For a comprehensive article on this issue, read Dr. Mary Enig and Sally Fallon's article on saturated fats. For a look at the history behind edible oils in the U.S., see their article "The Oiling of America."
One of the best ways to study the affects of coconut oil on human nutrition is to look at populations that get most of their caloric intake from the saturated fat of coconut oil. Logic would dictate that if the modern lipid theory of heart disease and obesity were correct, those populations with the highest consumption of saturated fats would be the most overweight and have the highest rates of heart disease. But such is not the case.
In a study published in 1981, the populations of two South Pacific islands were examined over a period of time starting in the 1960s, before western foods were prevalent in the diets of either culture. The study was designed to investigate the relative effects of saturated fat and dietary cholesterol in determining serum cholesterol levels. Coconuts were practically a staple in the diets, with up to 60% of their caloric intake coming from the saturated fat of coconut oil. The study found very healthy people who were relatively free from the modern diseases of western cultures, including obesity. Their conclusion: "Vascular disease is uncommon in both populations and there is no evidence of the high saturated fat intake having a harmful effect in these populations."
Another study was done on the Indian subcontinent comparing traditional cooking oils with modern oils in relation to prevalence of atherosclerotic heart disease and Type-II diabetes. Their conclusion: "In contrast to earlier epidemiologic studies showing a low prevalence of atherosclerotic heart disease (AHD) and Type-II dependent diabetes mellitus (Type-II DM) in the Indian subcontinent, over the recent years, there has been an alarming increase in the prevalence of these diseases in Indians--both abroad and at home, attributable to increased dietary fat intake. Replacing the traditional cooking fats condemned to be atherogenic, with refined vegetable oils promoted as "heart-friendly" because of their polyunsaturated fatty acid (PUFA) content, unfortunately, has not been able to curtail this trend. Current data on dietary fats indicate that it is not just the presence of PUFA, but the type of PUFA that is important--a high PUFA n-6 content and high n-6/n-3 ratio in dietary fats being atherogenic and diabetogenic. The newer "heart-friendly" oils like sunflower or safflower oils possess this undesirable PUFA content and there are numerous research data now available to indicate that the sole use or excess intake of these newer vegetable oils are actually detrimental to health and switching to a combination of different types of fats, including the traditional cooking fats like ghee, coconut oil and mustard oil, would actually reduce the risk of dyslipidaemias, AHD and Type-II DM."