I am sure you are all aware of the constant controversy surrounding fats in our diet – what is ‘good’ and what is ‘bad’. However, there is minimal argument surrounding the role of ‘trans fats’ in our diet. Indeed, it is now considered an indisputable fact that they have a detrimental effect on our health.
It was reported in the ‘Harvard Health Publication’ in February that “for every 2% of calories from ‘trans fat’ consumed daily, the risk of heart disease rises by 23%.” An incredible statistic and one that begs the question; if this is the case, why are we still consuming them?
What are ‘trans fats’?
‘Trans fats’ are a form of unsaturated fat that act more like a saturated fat because of their chemical structure. They are uncommon in nature but became a common choice for food manufacturers for use in margarine, snack food, packaged baked goods and frying fast food from around the 1950’s.
Artificial ‘trans fats’ go through a process called ‘hydrogenation’ which solidifies the oil. ‘Trans fats’ are frequently used by the food industry because they ‘improve’ flavour stability and the shelf life of food.
Please note that natural ‘trans fats’ can be found in nature but are not common. Conjugated linoleic acid is the only known ‘trans fat’ that is profoundly beneficial to health and is present in meat and butter.
The danger of ‘trans fats’
‘Trans fats’ alter the configuration of cell membranes and also block the essential enzymatic processes necessary for the metabolism of fats. Medical professionals consider ‘trans fats’ to be one of the most unhealthy compounds found in today’s food. They are manufactured when an oil is heated to a point that changes its chemical structure. Extra hydrogen atoms are bubbled into the hot oil in order to make it more stable for food preservation. Although these fats look chemically similar to their natural fat counterparts, they are not natural at all, and this confuses the body.
It has been reported that cutting commercial ‘trans fat’ intake from 2.1% of daily energy intake to 1.1% could potentially prevent 72,000 cardiovascular deaths.
A fat is a series of three fatty acids, or a chain of carbon atoms. Depending on the chemical structure of the fat, it can have a profoundly different impact on the body. ‘Cis fats’ make up the general structure of the fats in our cell membranes and have hydrogen atoms bound to the same side of the carbon in the fatty acids, this allows a ‘kink’ or ‘bend’ in the chain and means that the fat is a liquid at room temperature and naturally fits into our cell structure.
However, in a ‘trans fat’ the bond is broken and hydrogen atoms are bound to the opposite sides of the carbon which means that the fatty acid has a straight structure. This would seem a relatively small change, however this structure changes the physical and chemical properties of the fat. It means they have the ability to stack on top of each other and also have a much higher melting point than ‘cis fats’ which makes them solid at room temperature. Because of this, it is especially difficult for your body to metabolise them, allowing the fat to simply sit on top of tissue around the body thus hindering the efficiency of important enzymatic processes.
Please note that although ‘hydrogenation’ is a process by which manufacturers solidify an oil, it is also possible to do this in your own home without realising. If you heat an oil to the point that it is ‘smoking’ then the chemical structure of the bond will change to a ‘trans fat’.
The following diagrams offer a basic structure of a ‘Cis fat’ and conversely a ‘trans fat’:
(Cis Fat) (Trans fat)
As you can see from the two images, in the structure of the ‘cis fat’ the bond is in tact allowing for a ‘kink’ in the chemical structure. Whereas, in the ‘trans fat’ the bond is broken meaning that the structure of the cell is straight.
Cell Membrane Function
The correct functioning of the cell membranes are vital for the efficient day-to-day functioning of the human body. The cell membranes in our body are made up of three factors: phospholipids, glycolipids, and cholesterol. Phospholipids are the largest component of the three.
The most vital component of every cell membrane is the phospholipid; a molecule that has a head and two tails. The head and tails of the phospholipid act like a magnet. The head has a positive charge, and the tail has a negative charge. This magnet-like component attracts and repels nutrients and waste products, which allows the former to be absorbed into the cell and the latter to exit out of the membrane.
Processed fats such as ‘trans fats’ play a negative role in cell membrane function. They are ‘mutated’ and through replacing the saturated and unsaturated fat that makes up the tails of the phospholipid, the membrane becomes much less permeable, and is essentially solid. As a result of this the membrane cannot absorb nutrients into the cell and the waste products can exit out of the cell. This basically ‘clogs up’ the cell with waste produce that is of no use to the body.
This is one of the vital causes for many of the neurodegenerative diseases that prevail today. The nerve cells begin to die because the cells are not getting the nutrients that they need and the fats also prevent the transmission of electrical impulses throughout the body – meaning that the nerves cannot efficiently transmit and receive signals.
As we have mentioned in previous blogs, inflammation is an essential part of the metabolic process and without it we would be dead. However, excess or ‘chronic’ inflammation is extremely dangerous and is widely recognised as being a possible root cause of many chronic diseases that prevail consistently in the western world.
Research from ‘The American Journal of Clinical Nutrition’ has demonstrated a link between the intake of ‘trans fats’ and an increase in systemic inflammation:
“A recent observational study and short-term randomized trial indicated that Trans fatty acid intake increases systemic inflammation in generally healthy persons. Because systemic inflammation is an independent risk factor for future heart disease, these findings suggest a novel potential mechanism whereby TFAs may affect the cardiovascular health of generally healthy persons.”
The mechanism by which ‘trans fats’ may increase inflammation involves prostaglandins, which are fat-derived hormones that regulate and modify many bodily functions, with inflammation being the most essential.
‘Trans fats’ block the important anti-inflammatory production of Prostaglandin 1 (PG1) and Prostaglandin 3 (PG3), which are derived from both omega 3 and omega 6. Both of these prostaglandins are essential anti-inflammatory agents.
Not only do ‘trans fats’ block the essential production of these fat-derived hormones, but they also provoke the activity of Prostanglandin 2 – a known inflammatory mediator.
Fat is an essential part of a healthy and balanced diet. However, as mentioned at the beginning of this article, the health implications of fats are varied depending on their source and chemical structure. In terms of diet, the key is to eradicate ‘trans fats’ from our diet and increase our intake of unsaturated fats – mainly omega 3.
Here are two the two fat compounds that are considered most beneficial to our health:
These have a single carbon-to-carbon double bond. Because of this they have two fewer hydrogen atoms than a saturated fat and a bend at the double bond. This structure keeps monounsaturated fats liquid at room temperature.
Good sources of mono-unsaturated fats include olive oil, peanut oil and most nuts, as well sunflower oils. However, it is essential that these are cold-pressed.
A polyunsaturated fat has two or more double bonds in its carbon chain. Omega 3 and omega 6 – ‘essential fats’ – are the two main types of polyunsaturated fats. They are required for the maintenance of normal bodily functions, and even more importantly they are ‘termed’ essential because our bodies cannot naturally synthesize them so they must be ingested via dietary or supplementary sources. They are used to build cell membranes and are essential for muscle development, blood clotting and cognitive function.
Essential fatty acids – Omega 3/Omega 6 Imbalance
Although we do need both omega 3’s and omega 6’s, it is becoming increasingly clear that an excess of omega 6 fatty acids can have dire consequences on our health. Many scientists believe that a major reason for the high incidence of many chronic diseases is the profound imbalance between our intake of omega 6 and omega 3 fatty acids.
Omega 6 is essential to the chemical process of inflammation and we need inflammation to survive. However, excess inflammation has the complete opposite effect – it is of great danger to our health. If the ratio between omega 3 omega 6 is imbalanced in your body (which for the majority it is) then there is likely to be excess inflammation in your body.
If the membrane phospholipids in your body are high in omega 6 then this promotes the ‘Arachidonic Acid Cascade’ that forms Prostaglandin 2 and Leukotriene 4 (pro-inflammatory eicosanoids).
However, if the diet is high in omega 3 fatty acids, then they will compete with arachidonic acid for enzymes necessary to form eicosanoids. If more omega 3 eicosanoids are formed (Prostaglandin 3 and Leukotriene 5 – anti inflammatory agents) then this means less inflammation.
A cause for concern
The problem then becomes clear. Our ancestors evolved on a diet with a ratio of omega 6 to omega 3 of about 1:1. However, a huge change in dietary habits over the last few centuries has changed this ratio to something closer to 20:1. It is believed that around 85% of people in the Western World are deficient in omega 3 fatty acid. As a result of this huge imbalance, omega 6 (pro-inflammatory) eicosanoids are much more likely to be produced in the body resulting in excess inflammation.
This just highlights the vast differentiation between the different types of fats and a need for moderation and balance. Although it is essential that we cut ‘trans fats’ entirely out of our diets, the huge imbalance mentioned above is also something that clearly needs to be addressed.
Fat is essential for the maintenance of health. But – especially in the Western World – we are consuming the wrong forms.
The primary food source of Omega 3 is fish and especially oily fish such as sardines, Shellfish, algae and seed oils such as flaxseed are other excellent sources (the latter ideal for vegetarians and vegans). Fish and crustacean sources have positive benefits requiring much smaller daily amounts than seed oils, for example, and provide omega 3 in a form that is well utilised by the body.
When we ingest Omega 3 our body breaks the fatty acids down to 2 other fatty acids – Eicosapentaenoic acid (EPA) and Docosahexaenoic acid (DHA), and these are the components our body uses for many essential activities such as the maintenance of eye health, cell membrane integrity, skin health, joint mobility, and normal liver function.
Unfortunately, in the United Kingdom there are currently no legal requirements for food manufacturing companies to label ‘trans fats’ so it is important that you actively look for the term ‘partially hydrogenated’ when assessing a label. If this term is present on the food label then the item almost certainly contains a ‘trans fat’.
Also – in terms of home cooking – make sure you never ‘overheat’ oil so that it is ‘smoking’ as this will break the bond and turn the fat into a ‘trans fat’.
As there are no specific guidelines relating to the consumption of ‘trans fats’ it is best to act via the philosophy of ‘the lower the better’ – ideally you do not want to be consuming ‘trans fats’ at all.
The key point when it comes to fats in general is that we are, on the whole, consuming a high amount of the unhealthy forms such as ‘trans fats’, and a low amount of the more healthy forms – namely polyunsaturated fats (omega 3). And whether one refers to completely eradicating the intake of ‘trans fats’ from our diet or addressing the imbalance of omega 3 and omega 6 – the weight of importance remains the same and is pivotal for the maintenance of our overall health and well being.
If you have any questions regarding the health topics raised in this article then please do get in touch via phone (01684 310099) or e-mail ([email protected])
Cytoplan Editorial Team
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