What are Trans fats and where do they come from?

In 1901 a German chemist Wilhelm Norman proved that liquid oils could become solid by a process called hydrogenation. This means that a liquid vegetable oil is heated in the presence of hydrogen to render it into a solid state (1).Originally it was first thought this process was due to lower costs versus natural solid fats like butter, however advocates state that because saturated fatty acids where found to be bad for you, the food industry wanted to switch to using unsaturated (good) fat, as the health benefits of these fats where becoming well recognised. Yet because of the unstable nature of unsaturated fats, hydrogenation allowed the vegetables oils to become solid and it also increase the shelf life of products being made with it. So when food manufacturers began substituting Trans fats for saturated fats in products, there was no conclusive evidence to point out the dangers for human consumption (2). There were suggestions however in the scientific literature as early as 1988 that Trans fats could be a cause of the large increase in coronary artery disease and in 1994, the United States of America estimated that Trans fats caused 30,000 deaths annually in the form heart disease (2), yet still these fats are widely consumed by many Australians.

So what's the problem with Trans fatty acids?

According to research studies, Trans fats:

• elevate cardiovascular risk factors:
• increase cancer risk factors: interfere with liver detoxification, change B and T immune cell ratios and interfere with the functions of anti-cancer fatty acids.
• interfere with insulin function: making diabetes worse, and more likely to occur.
• decrease testosterone, increase abnormal sperm, & interfere with pregnancy in animals
• correlate with low birth weight babies, & lower human breast milk quality;
• change the fluidity of cell membranes, making them more leaky, thereby lowering cell vitality; and
• interfere with the healing fats, essential fatty acids - required for health (3).

Which are worse - saturated fatty acids or Trans unsaturated fatty acids?

Cholesterol is a soft, waxy substance found among the lipids (fats) in the bloodstream and in all your body's cells. LDL cholesterol is manufactured in the liver and is used to form cell membranes and involved in the production of sex hormones, among other things. HDL cholesterol is also involved in the formation of cell membranes and it also gathers excess LDL cholesterol flowing in the bloodstream that is not essential for bodily functions, returning them to the liver to be re-cycled or excreted from the body. When there are excess levels of LDL cholesterol in the blood stream, it can line the arteries creating plaque that ultimately leads to blockage of the arteries. The blockage can lead to a heart attack, stroke or other complications. Both saturated fats and Trans fatty acids are bad for you. Saturated fats are almost always found in foods that also contain cholesterol, and they increase your LDL cholesterol. Trans fats, even though originating from good fats, are even more detrimental to one’s health as they not only increase your LDL cholesterol; they also decrease you HDL cholesterol. This suggests that Trans fatty acids increase the risk of heart disease more than the intake of saturated fats (4), yet no studies have been conducted to definitively say which is worse.

Where are Trans fats found?

Trans fats are found in processed and convenience foods:

• Trans fats are present in partially hydrogenated vegetable oils, which are found in many margarines and in shortening.
• Trans fats are widespread in processed foods, including some muesli bars, breakfast cereals, low fat foods, fish sticks, frozen pizza, and other frozen foods.
• Trans fats are abundant in many baked goods (baked badly?) such as donuts, crackers, cookies, cakes, bread, and frostings.
• Trans fats are present in some puddings, peanut butter, instant soup mixes, and microwave popcorn.
• Trans fats are used in some spreads, sauces, dips, and gravy mixes.
• Trans fats are part of powdered non-dairy coffee creamers.
• Trans fats are used for frying in many fast food restaurants.
• Trans fats are present in fries packaged for home frying.
• Many potato and corn chips are fried in partially hydrogenated vegetable oils containing Trans fats.
• Trans fats are present even in some cooking oils (3).

Not all of the above foods contain Trans fats, as all the above foods can be made with out Trans fats. You as a consumer need to understand and read food labels in order to find out whether they contain Trans fats. The words “partially hydrogenated vegetable (or corn, or soybean, or canola) oil” or the words “vegetable shortening” indicate that Trans fats are present. If you need to buy a product that contains Trans fats, ensure that Trans fats appear at the end of the ingredient list, as this indicates that is it present in low qualities.

By law food manufactures do not need to state the amount of Trans fatty acids in products, therefore you need to do some math. All packaged food must include a nutritional information panel. On this panel fat content, including the proportion on saturated fat is required (5). Even though not mandatory at this stage, nutritional information panels will often state the amount of monounsaturated and polyunsaturated in the product. Therefore you can subtract the sum of the saturate, monounsaturated and polyunsaturated fatty acids from the total fat content to get the total amount of Trans fat in a product. Consumers choices will be made that much easier when it becomes compulsory to list the trans fat content of every manufactured food product, yet when FSANZ (Foods standards Australia New Zealand) considered whether to make mandatory labeling of trans fats, they decided it was more important to reduce the intake of saturated fat, hence to date unless a product makes a nutritional claim about cholesterol, saturated, unsaturated or trans fatty acids, FSANZ does not require manufactures to label the trans fats in foods (6)..

Can our body get rid of Trans fats?

Luckily our body has ways of dealing with these un-natural forms of fats, however our body’s capacity to destroy trans fats is limited and when our intake exceeds this limit, disease begins to manifest, as our body attempts to use this fats for vital structures and functions. The limit to which our body can deal with trans fats has yet to be clearly determined hence the need to limit our intake of trans fats as much as possible (3).

How can I decrease my intake of Trans fats in my diet?

Until we, as the consumer are given more information about the content of trans fats in manufactured products it is almost impossible to avoid trans fats, however you can take positive steps to reduce the amounts you consume:

• Avoid or reduce your intake of commercially prepared baked goods, snack foods, processed foods and fast foods
• Select soft margarines and liquid vegetable oils that contain no trans fats
• Learn to read food labels and the ingredients list on all manufactured products, choosing to buy products that have no or very little amounts of trans fats

So hopefully you have a better understanding of what these evil fats do to our bodies – lets vote with our dollars and purchase products that contain no or low amounts of trans fats and hope that Demark, Australia will soon ban any product that contains high amounts of this unnecessary fat!

Rachel Clark (Personal Trainer / Nutritionist)