There are two main types of fat: saturated fats and unsaturated fats. However, there is also a third type knows as trans fats. Trans fats occur naturally in very small amounts within dairy products and certain types of meat. Trans fats from these sources usually isn’t that much of an issue – the problem stems from the trans fats pumped into commercial goods, particularly baked goods.

See, the problem is that trans fats cause a rise in the amount of harmful LDL cholesterol in the bloodstream whilst reducing the amount of beneficial HDL cholesterol. This makes your body more prone to inflammation which is linked to heart disease, stroke, diabetes and other chronic conditions.

What Are Trans Fats?

Think about the typical fats you would find in a supermarket: coconut oil, olive oil, sunflower oil, lard and butter. Some of these are solid at room temperature and others are liquid.

The solid cooking fats are lard and butter – these are saturated fats. This means that all the carbon atoms are joined to as many hydrogen atoms as possible within the fat molecule.

The fats that are liquid at room temperature are unsaturated. This means that within their structure, there is a double bond between carbon atoms giving the fat a lower boiling point, hence why it is liquid at room temperature.

Saturated and cis-Unsaturated Fat Molecule

Trans fats are a type of unsaturated fat. This is where things get slightly more complicated. In nature, around the C=C (carbon-carbon double bond) both hydrogens are found in cis transfigurations as opposed to trans transfigurations.

In a ‘cis’ transfiguration, both hydrogen atoms attached to the carbon’s in the C=C are on the same side. In a ‘trans’ transfiguration, both hydrogen atoms are attached on opposite sides.

Trans (left), cis-unsaturated (middle) and saturated (right) fat molecules. Note that each corner of the ‘zig-zag’ represents a carbon atom. Hydrogen atoms are joined to each carbon atom so that 4 bonds are formed.

Trans fats still contain a double bond, however the rearrangement of the hydrogen atoms around the C=C. This small change in chemical structure is believed to be responsible for numerous health issues associated with trans fats. Due to the more linear structure formed, unsaturated fats which were liquid at room temperature can be made solid at room temperature by forcing the double bond to become a single bond and adding a hydrogen atom to the opposite side.

Different fatty acid molecules

This is known as partial hydrogenation and you usually find this on labels as ‘partially hydrogenated oils’. If you see a label for ‘hydrogenated oils’ this means that the cis-unsaturated fat has had hydrogen atoms forcibly attached to form a saturated fatty acid – these should also be avoided if possible.

Foods Rich in Trans Fats

If possible you want to avoid foods rich in trans fats as these tend to increase your risk of chronic diseases. Whilst small amounts of transfats generally aren’t a problem, if you consume any of these foods that may contain transfats on a regular basis, you may want to check the ingredients just to be safe as this could have damaging effects to your health over time.

Foods that are known to contain trans fats include:

  • Cakes, pies and cookies (particularly with frosting)
  • Biscuits
  • Breakfast sandwiches
  • Margarine
  • Fried fast food
  • Vegetable oils (when heated to fry foods at high temperatures)
  • Crackers
  • Deserts
  • Pastries, doughnuts and croissants
  • Frozen pizza
  • Processed meats

In the USA, the main thing to look out for on the labelling is for the trans fats label underneath where it says fats. However, note that products which contain less than 0.5g of trans fats per serving (this could be 100g or 16g or any other amount) can call themselves trans fat-free.

However, in the UK there is no obligation for manufacturers to state the number of grams of trans fats in their product.

Because of this, you should look out for the word: hydrogenated on the labelling where the ingredients are. If this word is there, you can be certain that the product contains trans fats so try to be mindful about consuming products with hydrogenated oils on a regular basis. The best way to avoid trans fats anywhere though is to try and limit processed foods, swapping them for whole foods i.e. roast chicken instead of chicken nuggets or homemade fries instead of store bought chips.

What About Trans Fats in Meat and Dairy Products?

The trans fats found in meat and dairy products are not something to worry about so much as several review studies have found that a moderate intake of trans fats does not appear to be harmful (1, 2, 3), so I would say that as long as you’re not guzzling meat and dairy produce down your throat you should be fine.

Ruminant trans fats have been a part of the human diet since we began eating animals so this is something we have been consuming for a very long time. These are trans fats from animals such as cattle, sheep, goats, deer, antelopes, cows, giraffes and the like.

They make up around 2-5% of the fat in dairy products and 3-9% of the fat in beef and lamb. In addition, ruminant trans fats contribute to far less trans fats than artificially produced trans fats within the average diet.

One of the most well known ruminant trans fats is conjugated linoleic acid (CLA), which is believed to be beneficial and consumed as a supplement due to some of the benefits such as: combating cancer, improving insulin action, reducing circulating glucose, preventing hypertension and reducing inflammation. it has been shown to have.

As well as this, ruminant trans fats have been found in larger amounts in dairy fat from grass-fed cows, which are healthier than your conventional grain or corn-fed cows.

Health Risks of the Regular Consumption of Trans Fats

Trans fats aren’t something to turn a blind eye to just because you enjoy your cakes, pies, cookies and the like. They’re certainly something you should at least be mindful of. In the UK, the NHS has acknowledged that between 2015 and 2020 a trans fat ban could save 7,200 lives, and that’s without considering all the health implications that the regular consumption of trans fats could have.

The main problem with trans fats is that they increase the ‘bad’ LDL cholesterol whilst lowering the ‘good’ HDL cholesterol.

Here are some of the health risks of consuming trans fats:

  • Increased risk of coronary heart disease.
  • Decreased insulin sensitivity and abdominal obesity (in monkeys) – seriously, this study is an interesting one though.
  • Excess inflammation such as heart disease, metabolic syndrome, arthritis, diabetes and other chronic diseases.
  • Damage to the endothelium (inner lining of blood vessels) and lowered ability of the arteries to dilate.
  • Increased risk of diabetes (there is growing concern over the correlation between the risk of type 2 diabetes and trans fat consumption)
  • Impaired memory and learning (which may lead to an increased risk of Alzheimer’s)

Summary of Trans Fats

Don’t worry about the consumption of ruminant trans fats from animal products.

Avoid industrialised, artificial trans fats – they are not good in any way whatsoever (do this by limiting processed foods).

Watch out for products with the word hydrogenated on the label, and try not to consume these products on a regular basis.

Whilst, I strongly believe trans fats should be avoided, this does not mean you cannot have these foods as part of a healthy lifestyle and enjoy them.

Were you aware of what foods contained trans fats? Let me know down below!