If a popular film is produced on fatty acids consumed in food, it might be titled, “The Good, the Bad and the Ugly”, with a nod to the Clint Eastwood film of 1966. The unsaturated fatty acids would be labelled as good, saturated fatty acids as bad and trans-fatty acids as ugly. This is based on the amount of damage they could do to the body’s arteries, by way of atherosclerosis (fat deposition) and thrombosis (clotting).
Of course, that would be a bit simplistic, as there are differences within the group of unsaturated fats, where the nature and extent of arterial protection and damage would vary between mono and poly-unsaturated fatty acids and the ratio of n-3 (omega-3) and n-6 (omega-6) fatty acids based on positioning of the terminal double bond within the poly-unsaturated fatty acid group. Also, there are differences between short chain and long chain fatty acids in the saturated fatty acid group. However, such nuances are not needed when we label dietary trans-fats as the most dangerous of fatty acids in terms of adverse health effects. Especially, in terms of the damage they do to blood vessels.
There have been a host of studies which corroborate the unequivocal “guilty” verdict on trans-fats in the context of dangerous assault on blood vessels. These fatty acids markedly raise the blood levels of atherogenic LDL cholesterol fraction of blood levels, much more than even the commonly incriminated saturated fats. The fraction of blood cholesterol which protects blood vessels (HDL cholesterol) is decreased. They increase the tendency of blood to clot, through activation and aggregation of platelets. They inflame the inner lining of blood vessels. There is also an enhanced risk of developing Type 2 diabetes. All of these script a villainous assault on arteries everywhere in the body. Involvement of the coronary arteries leads to heart attacks. Similarly, there is an increased risk of stroke and paralysis when blood vessels supplying blood to the brain are affected. Arteries supplying blood to the limbs too can be compromised.
Trans-fats can be of natural origin, produced in the gut of ruminant animals and found in milk and meat sourced from them. However, trans-fats in human diet are now mostly derived from industrial processes, which partially hydrogenate liquid vegetable oils to make them more solid. Apart from enhancing taste and texture of the food products which use them, their use lengthens the shelf life of the foods which contain them. Unfortunately, they also shorten human life when frequently consumed.
They are often found in baked products such as pastries, biscuits, frozen pizza, margarines and other spreads as well as fried foods like doughnuts. Industrially produced trans-fats have a more deleterious effect on blood vessels than those present in natural foods. This is understandable, as the human physiology has not adapted to these industrial products which have assaulted our bodies only in the past half century.
Cardiovascular disease, principally manifesting as coronary heart disease and stroke, is the leading cause of death worldwide. This burden is not only evident in high income countries but is rising fast in middle and low income countries. Diet plays an important role in the prevention of cardiovascular disease and diabetes. While promotion of diverse diets as a combination of several healthy natural foods is contingent both on food policies and personal choices, there is a pressing need to eliminate the source of harm which is related to industrial processing rather than having a natural origin. Even as we promote the consumption of good fats and reduce the consumption of bad fats, there is compelling logic to eliminate the ugly fats which were foolishly introduced into our foods.
The World Health Organisation (WHO) estimates that 50,00,000 lives are lost due to premature deaths from coronary heart disease which are attributable to consumption of trans-fats. Yet five billion people are still extremely vulnerable to their harm globally, because of absence of national policies directed at their elimination from industrially processed foods. Several countries, including India, have started implementing policies which mandate the reduction or eliminate the levels of trans-fats in food products. However, many other countries have not pursued that path. WHO’s call for elimination of trans-fats by 2023 has not been heeded or pursued with the needed level of political and policy commitment. Without such commitment, dominant sections of the food industry will be in no hurry to change their practice. In a globalised world, this spells danger to all countries. Policy makers have also been preoccupied with the COVID-19 pandemic. Now that the pandemic threat is abating, can there be a renewed global thrust to counter this global threat? Time for countries to come out of a trance to eliminate the danger from trans-fats.
(K. Srinath Reddy is Honorary Distinguished Professor, Public Health Foundation of India. Views expressed are personal).
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