December 2019 theStar; There is one thing that everyone in the nutrition field, myself included, agrees on – foods containing artificial trans-fats are absolutely the worst you could eat. We’ve long suspected that trans-fats increase the risk of heart disease by promoting inflammation, and we now have good quality evidence supporting this position. Artificial trans-fats are downright dangerous and rather than being minimised, they should be avoided altogether.
There are two types of trans-fats – natural and artificial. Trans-fats, also known as trans-unsaturated fatty acids or trans-fatty acids, are a type of unsaturated fat. Natural trans-fats are formed by the bacteria that reside in the stomachs of ruminant animals, and they make their way, in small amounts, to the milk or meat products that we consume. Butter, for example, contains about three per cent trans-fat.
On the other hand, artificial trans-fats are mainly formed during hydrogenation. Hydrogenation is an industrial process that uses heat and pressure to add hydrogen molecules to liquid oils. This is one of a number of methods that give margarine and shortening a harder consistency. It also extends their shelf-life. Hydrogenation turns some of the vegetable oils into trans-fats, which resemble saturated fat, but are distinctly different from natural, healthy saturated fat.
Trans-fats are known to cause inflammation and the hardening of arteries, raising your risk of death from heart disease and stroke. Trans-fats can also interfere with normal function of cells, nerves and the brain.
In light of the scientific consensus, nutrition authorities worldwide consider all artificial trans-fats harmful to health and recommend that their consumption be reduced to trace amounts, or eliminated altogether. In 2018, the World Health Organisation introduced a 6-step guide to eliminate industrially-produced trans-fats from the global food supply.
A number of food producers, under pressure from consumer lobby groups or national legislation, have agreed to cut out trans-fats. This is a good move, and far fewer trans-fat containing products are on the market. So why am I still raising concerns? Because a number of foods still contain them, in disguise. Often listed as ‘mono and diglycerides of fatty acids’, they can be found in many products including donuts, pastries, ice-cream, cooking fats and bread. Emulsifiers are chemical compounds that help prevent some of the constituent ingredients of a food from separating out from each other.
Worldwide, shortening has been falling out of favour and fashion because of its high trans-fat content, necessitating reformulation by manufacturers. The term “shortening” technically refers to any type of fat that is solid at room temperature. We have a number of these brands in Kenya which remain very popular due to their low consumer cost and long shelf-life. To draw attention away from what you’re actually buying, these fats are heavily marketed as being ‘vegetable-based’ and ‘cholesterol-free’, with added vitamins – attributes that many consumers are looking for in foods today. However, as more and more people become enlightened on the dangers of these fats and on the fact that dietary cholesterol is safe to eat, fewer are choosing to purchase these products, opting instead for more natural fats and oils, such as olive oil and coconut oil.
The primary dietary source of trans-fats in processed food is ‘partially hydrogenated oils’. These appear in highly processed junk foods and are the worst fats, and foods, that you can eat. Examples include fried foods like donuts and potato chips and baked goods like cakes and biscuits. Recall that these foods are also high in added sugars – a double blow for those seeking to lose weight or gain health.
The evidence agrees. Recent studies have confirmed that excessive consumption of trans-fats and carbohydrates from refined starches or sugars were associated with a higher risk of heart disease.
Many restaurants and takeaway shops fry potato chips in vegetable oil, which can contain trans-fats that permeate the food. Furthermore, high frying temperatures can increase the trans-fat content each time the same oil is re-used for frying.
In summary, be mindful that a food may be labelled as “0% trans-fat”, yet still contain trans-fatty acids from emulsifiers. Here, we should ignore the front-of-package marketing and always read the ingredients list. I’m always suspicious of food packaging that contains heavy marketing. I often suspect that they are trying to draw my attention away from something less appealing that the said food contains.
Remember that real, whole food contains next-to-no packaging. Think of the foods sold in an open market as opposed to a supermarket. Perhaps therein lies the clue – eat real, whole food.
Until next time.Dr Nyambura Mburu is a UK based Consultant Physician and Obesity Management expert.