John Myers
Trans fats are harmful fatty acids that can contribute to a variety of diseases. There is now an upper limit for trans fats in industrial foods in the EU. Here you can find out where else trans fats are contained and how you can avoid them as best as possible.
Trans fats are found in many foods
Trans fats (also known as trans fatty acids) are particularly found in industrially heavily processed products: in French fries, crisps, donuts, and puff pastry, instant soups, gravy, sausage, and even in muesli.
Trans fats are also formed when oil is overheated during frying and frying, and they occur naturally in dairy products and meat. Fat is an essential nutrient that has many functions in the body. But trans fats are not included. They are harmful to health and should be avoided as much as possible.
In recent years, under pressure, the food industry has made many efforts to reduce trans fat content in foods. Among other things, there has been an upper limit for trans fats in industrially processed foods in the EU since April 2021. The trans fat content may no longer exceed 2 percent per 100 g of fat in the product. Are unhealthy fatty acids a thing of the past?
What exactly are trans fats?
What exactly are trans fats? And how are they different from regular fatty acids? All fatty acids are made up of carbon chains. In the case of unsaturated fatty acids, there can be isolated double bonds between two carbon atoms in these chains. This is not the case with saturated fat. Saturated fatty acids therefore never have double bonds.
However, fatty acids are not just made up of interconnected carbon atoms. Every carbon atom has two hydrogen atoms wherever there is a single bond. However, the two carbon atoms that are linked by a double bond each have only one hydrogen atom. A trans fatty acid or a normal fatty acid can be identified by where these two hydrogen atoms are in the chain.
The difference between regular fats and trans fats
If both hydrogen atoms are together on one side, i.e. either both are on top or both are on the bottom, it is a normal, i.e. natural, unsaturated fatty acid. It is said to have the cis configuration because both hydrogen atoms are on the same side (cis is Latin and means this side). This creates a kink in the chain at the site of the double bond.
Trans fatty acids, on the other hand, can be recognized by their so-called trans configuration. This means one hydrogen atom is at the top of the chain and the other at the bottom. Trans is also Latin and means beyond, which means that a hydrogen atom has “jumped” to the other side of the chain, to the afterlife, so to speak. As a result, the chain can no longer bend and is straight instead.
Why trans fats are harmful
Bent fatty acids are ideal because they are built into our cell membranes (which consist of fatty acids, among other things) when we eat something fatty, and their kinks give the membranes a healthy and important elasticity. However, if the straight-ahead trans fatty acids are consumed, then these are also built into the cell membranes. Now, however, the cell membranes lose their elasticity and thus their ability to function.
This is how trans fats are formed
Trans fats occur naturally in certain foods, but they also occur during industrial processing and when fats are improperly prepared at home and in restaurants.
Industrial trans fats by hydrogenating fats
Trans fats or trans fatty acids are produced, for example, during the industrial hardening of vegetable fats (so-called hydrogenation). When the fat hardens, the structure of the fat changes from liquid to spreadable to solid. If fats are only partially hardened, i.e. made spreadable, trans fats are formed. If, on the other hand, fats are completely hardened, the proportion of trans fatty acids drops toward zero.
Before the health risks of trans fats were examined, fats for margarine, nut nougat creams, and the like were mostly partially hydrogenated. However, since the harmful effects of trans fats became known, the food industry has increasingly switched to fully hydrogenated fats. As a result, the trans fat content in finished products has fallen in recent years.
Natural trans fats in animal products
However, trans fats also form naturally in the digestive tract of ruminant animals such as cows, sheep, and goats. There, the unsaturated fatty acids from their food are converted into trans fatty acids by microorganisms. Humans then in turn absorb these trans fatty acids by consuming dairy products and meat. The fat from meat, milk, and co. consists of 2 to 3 percent trans fats.
It has long been assumed that natural trans fats, produced in the digestive tract of ruminants, are less harmful than trans fats produced during the processing of foods. However, recent research suggests that this is not the case.
Trans fats are formed during oil processing
Trans fats can also form during the processing of refined vegetable oils. In so-called deodorization, the oil is heated with steam at up to 250 degrees to remove unwanted odors and flavors.
This creates between 0.5 and 1.5% trans fats in refined oils, which isn’t much. Cold-pressed and virgin oils are not deodorized and therefore contain hardly any trans fats (less than 0.1%).
Trans fats are formed when oil is overheated
If you use an unsuitable oil for frying and frying, this can also result in trans fats. Because not every oil can withstand high temperatures. The decisive factor is the smoke point, i.e. the point at which oils begin to smoke and decompose.
The most heat-stable are coconut oil and high-oleic sunflower and rapeseed oil (“high oleic oils”). High-oleic sunflower oil and high-oleic rapeseed oil can withstand temperatures of up to 210 degrees due to the cultivation of special plant varieties. Temperatures of up to 180 degrees usually occur when deep-frying, and up to 200 degrees when roasting.
In principle, however, the amounts of trans fat produced when cooking with vegetable oils are kept within limits: if native or refined vegetable oils are fried for 54 hours, the maximum content of trans fatty acids is 2% (from originally 0 to 1.5%) – but of course, nobody would think so long to fry.
Trans fatty acids are also formed when oils are repeatedly heated. Because if the oil cools down and is heated again, it decomposes more. In sunflower oil, the trans fat content doubled (from 0.12 to 0.24%) from the first to the second frying at 190 degrees.
Where are trans fats found?
Below is a list of foods that contain trans fats:
- Ready-made products and meals (e.g. ready-made pizza, fish fingers, dry soups)
- Baked goods such as croissants, donuts, donuts, puff pastries, etc.
- Fast food and fried foods (e.g. French fries, chicken wings)
- Sweets
- Salty snacks: chips, popcorn, flips, etc.
- Spreads: margarine, hazelnut spread, peanut butter, etc.
- Spreadable sauces and dips (e.g. mayonnaise, remoulade)
- Dairy products: butter, milk, yogurt, milk chocolate
- Meat from ruminants: cows, sheep, goats, etc.
- Muesli and granola bars
- Ghee (clarified butter)
The upper limit for trans fats in the EU
The WHO recommends consuming less than 1% of daily energy from trans fats. That equates to an upper limit of 2.2 grams of trans fat at 2,000 calories per day ( 2Trusted Source ). Since April 2021, the EU has had an upper limit for trans fats of 2% per 100 g of fat in industrial foods – i.e. 2 grams per 100 g of fat. Previously, there was only a limit of 3% for baby food and olive oil.
Only the obligation to declare with the inscription “contains partially hydrogenated/hydrogenated fats” previously offered a clue. Nevertheless, it is hardly possible for the consumer to estimate whether he is exceeding the 1 percent limit recommended by the WHO or not.
That’s how many trans fats we eat
Unfortunately, no current figures on trans fat intake in the population can be found. It would be interesting to see what exactly the food manufacturers’ efforts and the EU cap have achieved.
According to a statement by the Federal Institute for Risk Assessment from 2013, the intake of trans fatty acids in Germany is harmless because it is only 1.6 g per day or 0.66% of the total energy – i.e. below the WHO recommendation. Only 10% of the population would eat a diet that consumes between 1% and 2% of dietary energy from trans fats.
However, the Federal Institute itself writes that the data on which this assessment is based is very inconsistent, as some very high and some very low trans fat levels were measured for each type of food. Frying oils and industrial baking ingredients, among other things, were also not included in the assessment – i.e. precisely those ingredients for which the trans fats are not declared in the bakery, at the snack stand, or in the restaurant.
According to a study, the age group with the highest trans fat consumption is 15 to 35 years old. The Federal Institute for Risk Assessment came to the same conclusion: Around 36% of 19- to 24-year-old men would get more than 1% of their dietary energy from trans fats – among 25- to 34-year-old men the figure was around 28%. For women, the figures are 22% for those aged 19 to 24 and 16% for those aged 25 to 34.
In a national comparison, Germany did not fare badly: In the TransFair study from 1999, 2.2 grams of trans fats per day were measured for Germany. At that time, the front runners were the USA with 8.1 to 12.8 grams and the Netherlands with 10.0 to 17.4 grams. On the other hand, the content was lower around the Mediterranean with 1.5 grams in Spain and 1.7 grams in Italy.
Trans fat intake in unhealthy diets
We have therefore calculated how many trans fats you consume per day with an unhealthy diet. For example, if you ate a croissant for breakfast, a hamburger for lunch, a Wiener Schnitzel for dinner, and then a third of a packet of chips and a third of a packet of cookies, you would have consumed about 1 gram of trans fat. So you would have to eat a very unhealthy diet to get more than the WHO recommended upper limit of 1% of your daily energy from trans fats.
For the calculation, we used the trans fat values of foods from the EU from 2016 (since no more recent figures are available so far). At that time, the EU upper limit of 2% was not yet in force. We therefore only used values from products that already complied with the EU upper limit of 2% at the time.
Why are trans fats used in food production?
With the invention of partially hydrogenated fats in the late 19th and early 20th centuries, trans fats were first specifically used in the food industry. They are used to make foods and oils last longer and to change their texture, for example, to make a spread spreadable. In addition, hydrogenated oils are cheaper than animal fats.
Towards the end of the last century, however, the number of studies showing the negative effects of trans fats on health and especially on the cardiovascular system increased, with the result that individual countries banned trans fats (USA) or imposed upper limits (Denmark).
How unhealthy are trans fats?
The WHO estimates that more than 500,000 people died worldwide in 2010 as a result of eating too much trans fat. Because trans fats increase the risk of many diseases. The following adverse health effects of trans fats have been identified so far:
- They worsen cholesterol levels
- They increase the risk of heart disease
They promote inflammation that is involved in the development of diseases such as diabetes, depression, Alzheimer’s, rheumatism, psoriasis, cancer, and chronic intestinal inflammation such as Crohn’s disease and ulcerative colitis - Trans fats increase the risk of depression
- They increase the risk of prostate and colon cancer
- Trans fats impair memory
- During pregnancy, they can reduce the baby’s birth weight
- They could lower testosterone levels and reduce sperm quality
- They promote acne
It should also be considered that trans fats often come from finished products, so they often contain all sorts of flavorings and preservatives as well as sugar, which has an additional negative effect on health.
Natural trans fats are also harmful
It has long been assumed that only industrial trans fats have a negative effect on health. Now, a study published in the American Journal of Clinical Nutrition found that natural trans fats are also detrimental to cholesterol and cardiovascular health.
As long as you eat a healthy diet and occasionally spread some butter or margarine on your bread, these trans fats won’t do you any harm. However, if you eat mainly animal products and ready meals, the situation is of course different.
Margarine: Hardly any trans fats anymore
In the past, there have been food producers who reacted to the dangers of trans fats at an early stage. Ultimately, however, it took public criticism to get the food industry to rethink. This has contributed to the search for alternatives that do not pose a health risk.
Margarine in particular suffered from the bad reputation of trans fats. Manufacturers, therefore, did a lot to reduce the trans fats in margarine even before the EU upper limit: Completely hardened vegetable oil is mixed with liquid vegetable oil to create a spreadable consistency.
Margarine made this way is virtually free of trans fats. In Germany, for example, the trans fat content in margarine fell from an average of 22% in 1994 to 1.8% in 2008.
How to avoid trans fats
Although our diet contains far fewer trans fats today than it did 10 to 15 years ago, trans fats should still be avoided as much as possible. You can further reduce your trans fat intake by observing the following points:
- Prepare your food fresh and do without ready-made products, fast food, etc. With our recipes for homemade margarine, instant powder for gravy, vegetable broth powder, and Co., you don’t even have to resort to industrial ready-made products, but can use high-quality food products in the best quality.
- When shopping, look for warnings such as “contains hydrogenated / partially hydrogenated fats” and avoid the respective products.
- Fry only in the hot air fryer, because much less fat is used than in conventional fryers.
- When using oils, make sure that they can be heated, and use coconut oil, high-oleic sunflower oil, or high-oleic rapeseed oil when frying and deep-frying. Refined peanut oil can be heated up to a temperature of 230 degrees, but as described above, it often contains trans fats as a result of the refining process. Unrefined peanut oil, on the other hand, can only be heated up to 170 degrees.
- The more saturated fat a vegetable oil contains, the more heat-stable it is, meaning you can use it for frying and other high-heating without trans fat build-up.
- The more unsaturated fatty acids a vegetable oil contains, the more sensitive it is, which means that you can only use it for cold cooking or add it to the food after cooking.
- If the oil begins to smoke while frying, you should stop using it. This is a sign that it has decomposed.
- Do not heat oil more than once.
- Rely on a healthy, vital substance-rich plant diet with as little industrial food as possible.
