The terms fats and fatty acids are often used interchangeably, in reality, fatty acids are a sub-unit of fats. You could say that fats are a storage form of fatty acids. Most of the fats we eat are technically called acylglycerols.
Acylglycerols (fats) can have one (monoglycerides) , two (diglycerides), or three (triglycerides) fatty acid groups. Monoglycerides and diglycerides don’t appear in large quantities in our food or bodies so triglycerides are the main fats referred to when discussing fats we consume or store in our bodies.
While almost all the fats we consume or store are triglycerides, fatty acids are also present in cell membranes as compounds called phospholipids. When fats are broken down, leaving your bodies fat cells and transported in the bloodstream, they are called free fatty acids. In order for a fatty acid to travel (be soluble) in liquid (bloodstream) it must be bound to a protein. Free fatty acids are bound to albumin (the major plasma protein in blood).
Fatty acid types
As mentioned earlier, triglycerides contain three fatty acids. It is the differences among these fatty acids that make one kind of fat different from another. Individual fatty acids serve different purposes in the body—some are “burned” or oxidized for energy, some are structural features of cell membranes, others are converted to different fatty acids or substances, such as sterols, while still others perform special duties in tissues, such as nerve cells.
Fatty acids belong to one of three types: saturated, monounsaturated and polyunsaturated. These names describe the structure of the fatty acid in terms of whether it is fully loaded with hydrogen.
Fatty acids also have different carbon chain lengths. Short-chain fatty acids have less than eight carbons. Medium-chain fatty acids have 8 to 14 carbons and long-chain fatty acids have 16 or more carbons. However, essential fatty acids from a nutritional perspective are considered short-chain if they have 18 carbons and long-chain with 20 or more carbons.
A lot of the confusion about fats comes from the various systems of naming these molecules, they have common names, numerical names, and systematic names. Most fatty acids we hear of are referred to by their common or numerical names.
Saturated Fatty Acids (vs Trans fats)
The carbons in these fatty acids are fully loaded with hydrogen, forming straight chains. Saturated fatty acids stack tightly, providing rigidity and making food fats – like butter – solid at room temperature. They have a similar effect in cell membranes. Many saturated fatty acids increase blood cholesterol levels and for that reason have been considered less healthful. However, this point is controversial as some saturated fatty acids do not raise blood cholesterol. They also have important structural properties and are a useful source of energy.
The fact is, all saturated fats are not created equal. The operative word here is “created,” because some saturated fats occur naturally while other fats are artificially manipulated into a saturated state through a man-made process called hydrogenation.
Hydrogenation manipulates vegetable and seed oils by adding hydrogen atoms while heating the oil, producing a rancid, thickened oil that really only benefits processed food shelf life and corporate profits. The medical and scientific communities are now fairly united in the opinion that hydrogenated vegetable and seed oils should be avoided.
These unsaturated fats, artificially manipulated into saturated fats, are also called trans
fats, and no doubt you’ve heard about them lately. Some cities and states have now outlawed their use. There is no controversy anymore regarding the health dangers of these artificially saturated fats.
Unfortunately, this rightful vilification of hydrogenated saturated fats has created a lot of confusion regarding naturally occurring saturated fats. If one form of saturated fat is bad for you, the argument goes, then all saturated fat must be bad. Nothing could be further from the truth.
Unsaturated Fatty Acids
These are called unsaturated because they do not have one or more pairs of hydrogens from their carbon chain. Unsaturated fatty acids include monounsaturated and polyunsaturated fatty acids. When hydrogen pairs are removed, the fatty acid molecule develops a kink or bend, known as a double bond. The more hydrogens missing, the more bent out of shape the fatty acid becomes. Unsaturated fatty acids, especially those with several double bonds, occupy more space, thereby making a fat containing them liquid (an oil) and cell membranes more fluid.
Essential Omega Fatty Acids
Omega-3s: These come in short- and long-chain varieties. The short-chain form is alpha-linolenic acid, the only omega-3 found in plants (except for some algae). It is found in flaxseed oil (53%), canola oil (11%), English walnuts (9%), and soybean oil (7%). EPA and DHA are abbreviations for eicosapentaenoic and docosahexaenoic acids, the long-chain or marine omega-3 polyunsaturated fatty acids found mainly in fish and shellfish. Compared with alpha-linolenic acid, both are elongated and highly unsaturated. Long-chain omega-3s can be made from alpha-linolenic acid, but humans perform this conversion very inefficiently. Possibly as little as 1% is converted in people consuming a typical western diet high in omega-6 fatty acids.
Omega-6s: Like omega-3s, this family of polyunsaturated fatty acids has its short-chain representative, linoleic acid, the most prevalent polyunsaturated fatty acid in western diets. Considered essential in its own right for healthy skin, it is high in several vegetable oils such as, sunflower, soybean and canola oils. Linoleic acid is converted to a limited extent to the long-chain fatty acid, arachidonic acid. Arachidonic acid is a vital constituent of cell membranes and an important source of substances involved in combating infection, generating protective inflammatory responses and promoting blood coagulation. It also has important functions in the communication between and within cells. Arachidonic acid is sometimes cast as a villain, but its many positive functions should not be overlooked.
Essential Fatty Acids: As mentioned these are polyunsaturated fatty acids that the body needs and cannot make for itself or derive from other fatty acids.
Traditionally, linoleic acid (short chain omega-6) and, more recently, alpha-linolenic acid (short chain omega-3) were the only polyunsaturated fatty acids considered essential because deficiency symptoms develop in their absence and, technically speaking, they can be converted to long-chain forms.
However, it is the long-chain derivatives – arachidonic acid (long chain omega-6) and DHA (long chain omega-3) – that are the most critical for the body’s needs. Having the ability to convert the short-chain fatty acids to their long-chain forms does not mean that humans make enough of them to meet the needs of brain growth and development. In fact, it is now clearly recognized that during pregnancy and infancy preformed DHA must be consumed for optimum brain growth.
Medium Chain Fatty acids
As mentioned earlier, fatty acids have different chain lengths. Because of their shorter chain length, medium chain triglycerides (also referred to as medium chain fatty acids) have a number of unique properties which give them advantages over the more common long chain triglycerides (long chain fatty acids).
Reduced chain length means that medium chain fatty acids are more rapidly absorbed by the body and more quickly metabolized (burned) as fuel. The result of this accelerated metabolic conversion is that instead of being stored as fat, the calories contained in medium chain fatty acids are very efficiently converted into fuel for immediate use by organs and muscles.
The energy-enhancing properties of medium chain fatty acids are attributed to the fact that they cross the double mitochondrial membrane very rapidly, and do not require the presence of carnitine, as long chain fatty acids do. Scientists attribute the increased energy from consumption of medium chain fatty acids to the resultant rapid formation of ketone bodies. Ketones being one of the two substances which the brain can utilize for energy (glucose, being the other). Medium chain fatty acids are thus a good choice for anyone who has increased energy needs: such as following major surgery, during normal or stunted growth, to enhance athletic performance, and to counteract the decreased energy production that results from aging.
Medium chain fatty acids are thus a good choice for anyone who has increased energy needs: such as following major surgery, during normal or stunted growth, to enhance athletic performance, and to counteract the decreased energy production that results from aging.
Medium chain fatty acids seem to offer a triple approach to weight loss, they:
- provide about ten percent fewer calories than long chain fatty acids
- are minimally stored as fat
- have been shown to enhance thermogenesis (contribute to enhanced metabolism to burn more calories).
This third property may be due to the fact that medium chain fatty acids behave metabolically in some fashion similar to carbohydrates, as well as promoting the development of ketones, as mentioned above.
Calorie-restricted diets are often associated with marked declines in energy. A number of studies support the benefits of using medium chain fatty acids in weight loss programs to boost energy levels and increase fatty acid metabolism to aid in reducing fat deposits.
Medium chain fatty acids have also been shown to suppress appetite, an ability of obvious benefit for those attempting to lower their intake of total calories.
Cholesterol and Atherosclerosis
Cholesterol is a compound of the sterol type found in most body tissues. Cholesterol and its derivatives are important constituents of cell membranes and precursors of other steroid compounds, but high concentrations in the blood are thought to promote atherosclerosis (a disease of the arteries characterized by the deposit of fatty material on their inner walls.).
Medium chain fatty acids have a number of properties that may be beneficial in preventing atherosclerosis.
- They have anti-coagulation effects, and have been shown to lower serum cholesterol in rats and calves. As well as reduce levels of cholesterol in the liver and other tissues.
- They have also been reported to act as antioxidants and reduce tissue requirements for Vitamin E.
- They also have a slight hypoglycemic (blood glucose-lowering) effect, and thus may be useful for diabetics.
To evaluate the immune-normalizing properties of MCTs, rats were injected with rabbit immune serum, known to cause severe autoimmune kidney disease in the rats. They then administered medium chain fatty acids in the diet, and noted that the pathological changes in the kidneys were much reduced in the medium chain fatty acids treated group. It was speculated that medium chain fatty acids could therefore have a positive effect on autoimmune reactions characteristic of the aging process.
Medium chain fatty acids have proven useful in treating a number of medical disorders that involve impaired or damaged lipid (fat) metabolism. These include obstructive jaundice, biliary cirrhosis, pancreatitis, cystic fibrosis, celiac disease, Whipple’s disease, Crohn’s disease, regional enteritis, and malabsorption in neonates. MCT has been reported to be useful for
MCT has also been reported to be useful for feeding of newborn infants, to both assist their initial growth and to contribute to their physiological development.
he absorption of calcium and magnesium appears to be enhanced when the diet contains medium chain fatty acids, particularly in infants, and the absorption of amino acids also appears to be improved.
Therefore, medium chain fatty acids can be a useful addition to the diet of those suffering from any form of malnutrition or tissue wasting.
The major adverse effect that is noted by beginning the use of medium chain fatty acids is nausea and gastric discomfort. This can be minimized or eliminated by starting with very small doses (i.e., about 1/4 teaspoon several times daily), and increasing the dose as tolerated. Before long, MCT can be taken by the tablespoonful.
Medium chain fatty acid oils can be used as a salad dressing, and as a cooking oil. However, they should not be heated to temperatures above 150-160 degrees C, because it will oxidize and breakdown.