Does Olive Oil Have Trans Fat

In this brief article, we will answer the question, “does olive oil have trans fat?”, what are trans fats, how they are formed while cooking, and why olive oil is considered the healthiest oil on Earth!

Does Olive Oil Have Trans Fat?

No, olive oil does not contain any trans fat, and even cooking olive oil under high heat does not produce trans fats. 

All oils will oxidize and hydrogenate to a minor degree when heated several times using high temperatures, such as those used in industrial frying processes. It has been documented that olive oil is less prone to oxidation and hydrogenation when heated than other oils when heated because it is rich in monounsaturated fat. Cooking with olive oil does not produce significant traces of trans fatty acids. In fact, olive oil is less prone to hydrogenation than other vegetable oils (1).

Olive oil is considered to be the most stable liquid fat to cook with, being naturally resistant to high temperatures. Also, olive oil is composed mainly of monounsaturated fats which are less likely to oxidize and turn into trans fats when heated.

Olive oil will ONLY turn into trans fat IF it is repeatedly heated and reused at extremely high temperatures. Formation of minor amounts of trans-oleic acid, inferior to 0.2 g/100 g fatty acids was observed for all the olive oil grades, which is lower than the trans amounts in other refined vegetable oils (1).

What Are Trans Fats?

Trans fats, or partially hydrogenated oils, are created when hydrogen is added to vegetable oils to solidify their consistency. Natural trans fats are also found in small quantities in certain beef and dairy products. Naturally occurring trans fat is mainly produced in the stomachs of ruminants (3).

The usual configuration of naturally occurring polyunsaturated fatty acids is the cis-form. Trans fatty acids in the diet are by-products primarily derived from fats chemically hydrogenated or hardened, such as fats used in the food industry and for frying or deep frying, but also from cakes, pastries and potato crisps. Compared to the cis form of unsaturated fatty acids, trans fatty acids have different physical and biochemical properties (2).

Artificially created trans fats are not considered good for health, since they increase the amount of low-density lipoprotein in the blood, also known as bad cholesterol while lowering the amount of good cholesterol or high-density lipoprotein.

This is why consuming large quantities of trans fats is linked with chronic health conditions, including obesity and heart disease.

Does Cooking Convert The Fat In Olive Oil Into Saturated/Trans Fat?

No, cooking does not change the composition of fats in olive oil. Turning oils into trans fats requires many hours of cooking the oil at very high temperatures, which generally does not occur during home cooking. The interconversion from cis to trans requires a lot of energy (~65 kcal/mole), however the use of a high temperature or a catalyst can enhance the reaction (1).

Saturated refers to the chemical structure of fat molecules, and this does not change on heating, even to high temperatures past the smoking point, which for olive oil lies between 365 and 400 degrees Fahrenheit. Unsaturated fatty acids contain double bonds in cis configuration causing a bend of the molecule, while trans isomeric fatty acids, similarly to saturated fatty acids, exhibit linear spatial configuration (3).

However, in many households all over the world oils are used not only once but reheated several times. During heating, many chemical processes occur, like the oxidation of different fatty acids and triacylglycerols, polymer or cyclic compound formation, loss of volatile compounds and the formation of polycyclic aromatic hydrocarbons. During the heating process the polyunsaturated fatty acid content of vegetable oils decreases while that of saturated fatty acids usually increases (3). 

So, if you need to cook at extremely high temperatures like those used for stir-frying, use canola or peanut oil which have an even higher smoking point than olive oil. 

Olive oil generally consists of 75 percent monounsaturated fat, 13 percent saturated fat, and 12 percent polyunsaturated fat, and this remains the same during and after cooking the oil.

The only way to convert unsaturated fats into saturated fats is via a process known as hydrogenation. 

On The Whole, Is Olive Oil a Good Cooking Oil?

Yes. Olive oil has been dubbed as the healthiest fat on Earth, and here are the reasons.

Nutritional Profile of Olive Oil

  • 124 Calories
  • 14 grams of fat (14 percent saturated, 73 percent monounsaturated, 11 percent polyunsaturated)
  • 13 percent of the Required Daily Intake (RDI) of Vitamin E
  • 7 percent of the RDI of Vitamin K

Olive oil excels in two main aspects of cooking oils: it has a moderately high smoking point and also shows oxidative stability. Both these properties mean that olive oil is not converted to trans fats during cooking. As a cooking medium olive oil has many functions, such as transferring heat from the heat source to the food, acting as a lubricant to prevent food from sticking to the cooking surface, adding flavor, crust and creating a more visually appealing look to the food. It is an extremely healthy oil to use for all types of cooking and there is a lot of existing and emerging research related to the health benefits due to high levels of antioxidants (some of which are unique to olive oil) and the ability of the oil to enhance the health attributes of some ingredients once cooked (1).

Here are a few other reasons why olive oil is the best oil to use for cooking:

  • Olive oil consists largely of monounsaturated fatty acids, which are relatively resistant to high temperature; heat-resistant monounsaturated and saturated fats constitute 87 percent of olive oil.
  • Olive oil is a rich source of vitamin E and various other potent antioxidants, which possess numerous health benefits. They help eliminate free radical species from the body that cause cell damage leading to various diseases, including cancer.
  • Even when exposed to very high temperatures for long periods, olive oil does not break down or develop a significant number of harmful or dangerous compounds. Again, this is mainly attributed to its high antioxidant content and low polyunsaturated fat content.
  • Certain experiments claim that intense heat and prolonged cooking destroy certain beneficial compounds in olive oil, including antioxidants. But remember; these reports are derived from studies where extreme methods and temperatures were applied. 

Conclusion

In this brief article, we answered the question, “does olive oil have trans fat?”, what are trans fats, how they are formed while cooking, and why olive oil is considered the healthiest oil on Earth!

If you have any more questions or comments please let us know.

References

  1. de Alzaa, Ana Florencia, Claudia Guillaume, and Leandro Ravetti. Cooking with Extra Virgin Olive Oil. 2021.
  2. Wahrburg, Ursel, Mario Kratz, and Paul Cullen. Mediterranean diet, olive oil and health. Euro J Lipid Sci Technol, 2002, 104, 698-705.
  3. Szabo, Zoltan, et al. Effects of Repeated Heating on Fatty Acid Composition of Plant-Based Cooking Oils. Foods, 2022, 11, 192.