Whether coconut oil is good for weight loss or not, it is becoming an increasingly popular component of a weight loss diet. So how justified is this in view the fact that fats and oils are not normally regarded as being the best form of food to take if you want to lose weight?
Apart from any other considerations, fats are actually very important components of any diet. Consider, for example, how many vitamins are fat soluble: vitamins A, D, E and K are all fat soluble, and without fats in your diet vitamins would not be able to circulate and be taken to where they do most good. Fats are also essential building blocks for hormones and cell membranes. In short, you cannot survive without fats. Coconut oil is a fat.
In referring to coconut oil here, we are discussing virgin oil, not the refined form that is high in cholesterol. Refined, or processed coconut oils, is hydrogenated, which renders it more in nature to the longer chain fatty acids. Virgin coconut oil contains what are known as medium chain fatty acids (MCFA), which are easily metabolized by your liver into energy.
The longer chain fatty acids, also called triglycerides, are not easily broken down into smaller components, and tend to be stored in the body as fat. This fat can be particularly dangerous if stored round the midriff, and so long chain fatty acids are dangerous to your health. This does not apply to MCFAs, and a possible mechanism for this is discussed later.
An inability to distinguish between the different types of fats and oils in your diet is largely due to a lack of education in the chemistry of fats, and the lumping together of all fats and oils under the 'fatty' flag. Perhaps it is the use of the word 'fat' for the overweight condition and the fact that the triglycerides and other chemicals are known generically as 'fats' that triggers a connection between the two, but although this is logical, and in some cases justified, it is not always the case. There are fats and fats, just as there are lubricating oils and greases, and edible cooking oils and greases.
The fatty acids in coconut oil are composed of relative small carbon chain lengths. Caprylic acid and capric acid contain 8 and 10 carbon atoms in the backbone compared to the 18 of the stearic acid that is commonly contained in animal fats. The longer the carbon chain in the molecule, the more difficult it is to break down, and the more likely it is to be stored in the body as a dense fatty deposit that places a strain on the heart.
Due to the shorter chain length the medium chain fatty acids hold less energy per unit weight. Apart from any other reasons then, coconut oil contains fewer calories than other fats and so if used as the bulk of your fat requirement, will be less liable to generate body fat. Not only that, but as inferred earlier, due to the smaller molecule these calories are more readily released as energy for use by your body rather than stored unused.
However, that is not the whole story on either count: coconut contains saturated fats, and also monounsaturated and polyunsaturated fats, although in small quantities. These, however, are present in only small amounts, although would still be expected to undergo oxidation and produce the rancid taste commonly found in aged unsaturated oils and fats. However, even after a year this does not happen, which indicates that coconut oil possesses some form of antioxidant properties. This is confirmed by the fact that people eating a diet rich in coconut oil has less of a need for the strong oil-soluble antioxidant vitamin E.
In fact, the metabolism of fats is usually connected with the carnitine transport system in the mitochondria, although the shorter chain fatty acids do not need carnitine for their metabolism. What happens then is that because carnitine promotes oxidation during stress, and causes oxidative damage to body cells, its absence in metabolism of coconut oil fatty acids results in a reduction in the oxidation that degrades unsaturated fats. Hence the lack of rancidity.
Taking this further, then, this lack of oxidation infers that those that take a diet rich in coconut oil (for example using it for cooking rather than animal and vegetable oils containing longer chain fatty acids) should be partially protected against cell oxidation in general. Oxidative effects such as aging, cardiovascular diseases and some cancers should be reduced, and studies have shown this to be the case. Those consuming coconut oil rather than other oils tend to age more slowly, suffer less from heart disease and tend to experience fewer incidences of cancer.
With regard specifically to weight loss, it is believed that consumption of medium chain triglycerides, as opposed to longer chain triglycerides, results in a higher rate of thermogenesis, or the conversion of carbohydrates to energy (fats are also carbohydrates). The first step in this process requires the presence of Coenzyme A in the form of the enzyme acyl-CoA-dehydrogenase, and measurement of the activity of this enzyme has indicated that medium chain triglycerides exhibit much higher expenditure of energy than the metabolism of long chain triglycerides when being converted to fatty tissue. However, though the energy used up in this reaction, known as lipogenesis, was higher, the formation of fatty tissue was the same.
Hence, MCA uses more energy to produce the same amount of fat as LCA, and therefore, although more energy is used up, no new fat is generated by the liver. Since your dietary fat intake can ultimately have only three fates: burned as energy, stored as the emergency energy source glycogen, or deposited as fat, then it is logical that the more energy generated then the less fat will be stored.
In this way, coconut oil, with a high content of medium chain fatty acids, has a scientific explanation for causing weight reduction when used as a source of fat in the diet rather than animal or other vegetable fats or oils. It is converted to energy rather than fatty tissue, and if you exercise to use up that energy then your weight loss can be significant.
What this theory also states, however, is that coconut oil should be used as a replacement for other fats, and not in addition to it. If you take coconut oil in addition to your normal diet, do not expect to see results.
No comments:
Post a Comment