Medium-chain Triglycerides (MCT) Oil
Medium chain triglycerides are reported to be thermogenic and known to support weight management by sparing lean body tissue. These oils are 100 percent pure and all vegetarian/vegan. These smaller chain triglyercides (MCTs) contain anywhere from 6 to 12 carbons and are fatty acid esters of glycerol. Unlike long-chain fatty acids which are absorbed into the lymphatic system when ingested, MCTs easily passively diffuse from the intestinal lining to the portal system. And, importantly, MCTs don't require the addition of bile salts from the gall bladder for digestion. Clinically, patients who are malnourished or who have abnormal absorption problems are given MCTs simply because they don't require energy to absorb, store, or make use of.
Where do you get MCTs? Medium chain triglycerides fatty acids are found in coconut and palm kernel oil. Since they are more easily absorbed than other kinds of fats they require very little assistance to be absorbed through the intestine. Since they go directly to the liver and are not packaged into chylomicrons where they are metabolized quickly, they increase energy utilization and at the same time slow down fat storage. Chylomicrons are fat/protein packages that are comprised of triglycerides, phospholipids, cholesterol and proteins. They have the ability to carry dietary lipids to various parts of the body. Chylomicrons are a member of lipoprotein carriers such as VLDLs (very low density liposomes), LDLs (low density liposomes), and HDLs (high density liposomes) that carry fats and cholesterol in the bloodstream.
Many studies indicate that bringing in MCTs into your diet in place of other unhealthy fats will help to maintain healthy body weight as well as promote lean muscle. It is important to keep track of the kind of fats you take into your system. Some fats are healthy and some are not. Good fats can actually help you to lose weight and at some point help to maintain healthy fat to muscle ratios.
Oil of the coconut happens to contain around 66 percent medium-chain triglycerides. The fatty acids that make up MCTs in coconut oil are; caproic acid (has 6 carbons), caprylic acid (has 8 carbons), capric acid (has 10 carbons), and lauric acid (has 12 carbons). As in other triglycerides, MCTs have a glycerol backbone with 3 fatty acids attached in parallel.
When taken as a dietary supplement it is suggested to take one tablespoon 1 to 3 times a day. If you're not keen on swallowing a tablespoon of these oils, you might consider using them as salad dressings or in sauces.
Clinically speaking, medium-chain triglycerides are considered a good source of energy as they are easily metabolized by the body. Since they are quickly absorbed by the intestine, they are used in the treatment of patients who have absorption problems. Supplementation of MCTs along with a low-fat diet has been used on patients who have Waldmann's disease which involves intestinal lympangiectasia. Basically this involves dilation of the lymphatic vessels of the intestine bringing about chronic diarrhea and loss of proteins such as albumin and globulin. The dilated lymph vessel cause reduced lymph flow that eventually leads to improper absorption of fat as well as fat soluble vitamins in the intestine. The lymph vessels may rupture causing protein loss into the intestinal lumen. MCTs have also been demonstrated to improve patients who have Alzheimer's and Parkinson's disease when added to a high protein diet.
As an aside, MCTs have a mild flavor relative to other fats and tend to be more stable than long-chain fatty acids. For that reason they are often used as solvents for flavors in oral medications and vitamins.
Fats that you take into your diet are often blamed for obesity seen in some patients. Keep in mind that all fats are not created equal. Long-chain fatty acids are processed by the body differently from medium-chain fatty acids. MCTs are known to be oxidized to a greater extent than their long-chain counterparts. For that reason, MCTs have less of a chance to be deposited into adipose (fat) tissue. Both animal and human studies demonstrate this. Since MCTs increase thermogenesis and lower fat deposition in fat tissue, the medical community suggests that it be used in weight-loss programs.
Palm-kernel oil is actually taken from the seeds of the oil palm. Don't confuse this with the oil taken from the fruit surrounding the seed known as palm oil. The oil palm is actually native to Africa and parts of Asia. Palm-kernel oil is more stable to high heat and is often used in cooking. It turns out that palm kernel oil is very similiar to coconut oil in terms of its saturated fat content and MCTs. Palm-kernel oil contains a little over 80 percent saturated fat which includes lauric acid, myristic acid, and palmitic acid. A little less than 20 percent is unsaturated fat made up of mostly oleic (monounsaturated) and a small percentage of linoleic acid (polyunsaturated). Keep in mind that not all saturated fats are bad fats. Each of the fatty acids has their own properties and affect cholesterol and fat metabolism differently. Palm-kernel oil contains high concentrations of lauric acid involved in thermogenesis and weight-loss simply because it is a MCT. So, palm-kernel oil and coconut oil complement each other nicely. Lauric acid is also known to have antibacterial, anti-viral, and anti-inflammatory properties. Due to the development of antibiotic resistance from the over use of antibiotics, these oils may be a good way to fight off infection and maintain a healthy gut.
There have been many misconceptions about cholesterol and fat in our diets. Most people have been told that a diet low in cholesterol and saturated fat will lower their chances of heart disease. Clinical studies are telling us everything but. To get a better understanding of this it helps to have some understanding of fat chemistry.
Most fats in our bodies and in the foods we ingest are in the form of triglycerides. What that means is that there are 3 fatty-acids attached to a glycerol molecule. Although elevated triglyceride blood levels have been linked to heart disease, these triglycerides do not come from dietary fats. They are actually made in the liver from excess sugar that has not been used to generate energy in the form of ATP. The source of these sugars comes from foods we eat that contain carbohydrates but in particular refined sugar and white flour.
How Fatty Acids are Classified
There are 3 ways to classify fatty acids based on hydrogen content which is saturated, monounsaturated, and polyunsaturated. Saturated means that all carbon atoms have hydrogen attached to them with single bonds between carbons. This fatty acid is chemically stable and will not go rancid and tends to be solid at room temperature. Our bodies make saturated fats from carbohydrates and are commonly found in animal fats and tropical oils. Monounsaturated fats have one double bond between 2 carbon atoms which means they are lacking 2 hydrogen atoms. Our bodies make monounsaturated fats from saturated fats. Due to the double bond, these fats tend to be liquid at room temperature. Monounsaturated fatty acids commonly found in our food is oleic acid and sources include avocados, almonds, olive oil and peanuts. Polyunsaturated fatty acids have two or more double bonds and therefore lack at least 4 hydrogen bonds. The most common polyunsaturated fatty acids found in food include linoleic acid (omega-6 fatty acid) and linolenic acid (omega-3 fatty acid). We can't make these fatty acids and therefore are essential to our diets. The extra double bonds in these fatty acids cause them to be liquid at most temperatures. These oils become rancid easily and should not be used for cooking. As a matter of interest, when the hydrogens attached to the carbons that have double bonds between them are on the same side, the oil is referred to as a cis form. If the hydrogens are on the opposite sides they are called a trans fat.
Keep in mind that fats/oils whether animal or vegetable are a mixture of saturated, monounsaturated, and polyunsaturated fatty acids. Animal fats tend to be solid at room temperature. Think of bacon fat once it cools (white solid). Vegetable oils vary in consistency. Vegetable oils (corn oil) that come from colder climates tend to contain mostly polyunsaturated fatty acids and tend to be liquid at room temperature. Vegetable oils from tropical areas contain mostly saturated fatty acids. These fats are liquid in the tropics but hard in northern climates. Coconut oil is a good example with a 92 percent saturated fatty acids. This increased concentration of saturated fats helps to maintain leaf stiffness.
Fatty Acid Length
Fatty acids are not only classified according to the amount of hydrogens they contain but also on the number of carbons they contain. These lengths are referred to as short-chain, medium-chain, and long-chain fatty acids. Short-chain fatty acids contain anywhere from 4 to 6 carbons. These are saturated fats such as butyric and capric acid found in butterfat. These fats are directly absorbed by the intestine for quick energy. Medium-chain fatty acids have 8 to 12 carbons and are mostly found in butterfat and tropical oils (coconut oil, palm-kernel oil). These medium-chain fatty acids are also absorbed directly the the intestine and provide quick energy. Long-chain fatty acids contain anywhere from 14 to 18 carbons and can be either saturated, monounsaturated, or polyunsaturated. Omega-3 and omega-6 fatty acids belong to this group amongst others. Gamma-linolenic acid (GLA) belongs to this group as well and is found in evening primrose, borage and black currant oils.
Good News About Saturated Fats
Saturated fats are actually good for you and not the cause of modern diseases. Saturated fats are an integral part of the cell membrane of all cells in our bodies. Saturated fats are required for calcium to be incorporated into bone. Saturated fats boost our immune systems and protect us from liver damage due to toxins such as alcohol and Tylenol. Short and medium-chain saturated fatty acids have been demonstrated to have antimicrobial action that protects our intestines. Medium-chain triglycerides promote weight-loss and help to maintain healthy muscle to fat ratios.
http://www.ncbi.nlm.nih.gov/pubmed/2619703 (palm kernel oil)
http://www.ncbi.nlm.nih.gov/pubmed/19301124 (MCT experiment on dogs)