Fats and oils – Part 5

Recommendations for fats and oils in your diet

In the last four weeks, we have been looking at the components of the mega nutrients known as fats and oils. Having done so, we are now in a position to recommend what fats and oils are good for human consumption and those that we should avoid. From those studies, one has also been able to present the health benefits of these nutrients, especially as it affects the cardiovascular (the heart and blood vessels) system.

By far the most significant finding in this our study of fats and oils is the formation of atheromatous plaques (deposits of cholesterol on the walls of the arteries). These plaques can grow big enough to occlude the vessels and cause either coronary artery disease (CAD) or stroke, depending on the arteries involved. Also, clots can form when the wall of the artery where these plaques are formed, cracks. These clots (thrombus) could block a blood vessel whose diameter is smaller than that of the thrombus. Here also we can have either CAD or stroke.

In order to have a good understanding of the recommendations which I am about to present, I would like to refresh our memories concerning the different fats and oils that we have discussed, these past four weeks.

First and most important of the fats and oils are the unsaturated fatty acids – monounsaturated and polyunsaturated. These are represented by omega 3 and omega 6 fatty acids. Omega 3 is the best-known example of an unsaturated fat.

There are three types that have been extensively studied which also play important roles in the health of humans.
1. Eicosapentaenoic acid – EPA
2. Docosahexaenoic acid – DHA
3. Alpha-linolenic acid – ALA.
Secondly, we have the saturated fats.

Saturated fats are fats that have single bonds connecting all the carbon atoms. In this kind of fat, there are no double bonds. The carbon atoms are bonded to other carbon atoms or hydrogen atoms by single bonds. The fat molecule is said to be saturated with hydrogen atoms. Saturated fats are characteristically solid at room temperature. Commonly, the word fat is used for fats that are solid at room temperature, while oils are reserved for fats that are liquid at room temperature. Most animal fats are solid at room temperature (they are saturated) and fats sourced from plants and fish oils are more often than not, liquid and these are the monounsaturated and polyunsaturated fats.
The third group that we discussed are the trans fats.

This has been described as the worst kind of fat that an individual can consume. It is an artificial kind of fat that is produced by heating liquid vegetable oils to very high temperatures and pumping hydrogen into it. The heat breaks the double bond in the unsaturated fatty acid into two halves and each half can become attached to hydrogen atoms making all the bonds single and saturated. This process is known as hydrogenation and the product is partially hydrogenated oil. Also called trans fatty acid, this product is solid at room temperature and has an extended shelf life. It increases the LDL (bad) cholesterol in the blood and decreases the HDL (good) cholesterol. A scenario such as this increases the risk of heart disease and stroke.
Cholesterol

This is a wax-like substance that is produced in the liver and is also found in certain foods that we eat. Cholesterol has far-reaching functions in the body and we humans cannot do without it.

Triglycerides

These are another kind of fats that play significant roles in the formation of atheromatous disease and heart disease. They are the main fat that make up the body fats in human beings and are vital energy sources in the body. They are stored in fat cells and released by hormonal action when there is a need for energy in between meals in the body.

Having presented the types of fats and oils in our bodies, we shall next be considering what roles – good or bad, that they play. With this in mind, we shall present the dietary recommendations for fats in next week’s Thursday’s edition of The Guardian Newspaper.