Trans fats are also known as ‘partially hydrogenated oils’ or ‘vegetable shortening’. They are made by bubbling hydrogen gas to unsaturated fats to make them resemble saturated fats. This process is known as hydrogenation...
Unsaturated fats are the “good fats” & are mainly from plants, while saturated fats are the “bad fats” & are mainly from animal sources. In a nutshell, hydrogenation changes the good fats into bad fats. They are found in baked products, some solid fats like margarine, biscuits, crisps, French fries, cakes, salad dressings & some liquid oil.
Partially hydrogenated oils don’t spoil as easily as non-hydrogenated fats. They can withstand repeated heating without breaking down. And the process can turn liquid oil into a solid, which allowed for easier transportation and wider uses; this solid plant fat is also much less expensive than solid animal fats. In the 19th century, this was thought to be a good thing because switching from butter or lard (both of which are from animal sources & contain high amounts of saturated fat) to a product made from healthy vegetable oil seemed to make sense.
Before the advent of partial hydrogenation, the only trans fat that humans consumed came from eating cows (or dairy products), lamb and deer; in ruminants like these, bacteria living in the stomach make small amounts of trans fat. But due to industrialization, by the early 1990s, trans fat intake averaged 4-7% of calories from fat.
Today, this process is found to be very disgusting and it amazes me to think that someone thought these fats would be suitable for human consumption. Trans fats adversely raise the levels of low-density lipoprotein (LDL)/ bad cholesterol and lower the levels of high-density lipoprotein (HDL)/ good cholesterol, they cause abdominal obesity, inflammation and insulin resistance.
In the long term, consumption of trans fats raises the risk of obesity, diabetes, heart disease, stroke, Alzheimer’s, depression and many more diseases.
The myth of margarine being a heart-healthy alternative to butter has been spread for years. Since margarine was made from vegetable oils, most people assume it is better for long-term health compared to butter, which was known to contain a lot of cholesterol and saturated fat. This is wrong. Research showed that some forms of margarine—specifically the hard stick margarines—were worse for the heart than butter. This was because they contained large amounts of trans fats from partially hydrogenated vegetable oils.
The Nurses’ Health Study (Harvard) found that women who ate 4 teaspoons of stick margarine a day had a 50% greater risk of heart disease than women who ate margarine only rarely.
Nutrition experts have not set a specific limit of trans fats in our food, because there are no known requirements for the body; we therefore need to avoid trans fats in our foods, because all they do is cause us damage.
As a consumer, check the nutrition labels on food packages for trans fats so as to avoid sickness in the future. Check the ingredient list for names like “partially hydrogenated vegetable oil” or “vegetable shortening” as they are synonymous to trans fats.
Secondly, read the labels for nutrient facts/content. It is best to buy trans-fat free foods, because when a package reads like the picture below (0.0g), it could mean that there is up to 0.5g of trans fats per serving. As much as this sounds very little, it adds up to a large amount as we eat these foods with time.
Also, choose liquid vegetable oils like olive, sunflower, peanut, canola or corn oil. Remember non-hydrogenated/ unsaturated/ ‘good’ fats are normally liquid at room temperature. They are the healthy fats & this means that any fat that solidifies at room temperature is an unhealthy saturated or partially hydrogenated fat.
In reality, we can never avoid ALL foods containing trans fats. The last resort is to eat products that list the partially hydrogenated oils near the end of the ingredient list; meaning that they are in the least amounts. In addition to avoiding them, we should replace them with foods rich in the unsaturated/ good fats and not with refined carbohydrates –this is a common mistake people make.