Flaxseed oil has recently been gaining momentum as a healthy oil due to its high levels of polyunsaturated fats; but how does it compare to the well-researched extra virgin olive oil? Read on to find out the differences between these two oils, and which one should be the everyday kitchen staple.
Fatty acid profile
Both extra virgin olive oil and flaxseed oil are full of healthy unsaturated fats, however they differ in the type. Flaxseed oil is predominately polyunsaturated fat (66%), with the main fatty acid being alpha linolenic acid1, while extra virgin olive oil is mainly monounsaturated fat (67%), with the main fatty acid being oleic acid1.
One of the main reasons why flaxseed oil is considered healthy is because it contains alpha linolenic acid (ALA), a plant-based omega-3 fatty acid. Omega-3’s are essential fatty acids (meaning the body cannot synthesize them and therefore they must be consumed via food) and have been shown to have beneficial outcomes on heart health2. However, ALA must be converted to other forms of omega-3 by the body in order to have these health benefits, and this process in inefficient with only a small percentage actually converted3,4. In fact, the best and most efficient source of omega-3 fatty acids is oily fish. So, while the ALA in flaxseed oil can provide bonus omega 3’s, it shouldn’t be considered the main source. The DHA and EPA found in oily fish are much more potent and efficient forms of omega-3 fatty acids, which is why health advice recommends consuming 2-3 serves of oily fish per week5.
Extra virgin olive oil is one of the most researched cooking oils in the world, and it has been shown to have numerous health benefits. In particular, extra virgin olive oil is the primary fat source in the Mediterranean Diet. This eating pattern has a strong body of evidence showing beneficial health outcomes on a variety of areas such as cardiovascular health, neurodegenerative diseases, and diabetes6. There is also evidence to support the health benefits of extra virgin olive oil as an individual food, due to its high levels of bioactive compounds. These bioactive compounds have antimicrobial, anti-inflammatory and antioxidant properties7.
In contrast, the evidence to support flaxseed oil for health is nowhere near as strong. While there have been some reported benefits for conditions such as diabetes, cancer prevention, and cardiovascular disease, the evidence is inconsistent and generally in animals8. It is also important to note that much of the evidence for these health benefits is for whole flaxseeds or flaxseed powder, rather than flaxseed oil.
Another major difference between extra virgin olive oil and flaxseed oil is the stability. Due to its high percentage of alpha linolenic acid, flaxseed oil is incredibly prone to oxidation making it highly unstable9. In fact, flaxseed oil is so unstable that it cannot be heated or used for cooking9. It must also be stored in a refrigerator and used within a few weeks, or it may go rancid.
There is an enduring myth that extra virgin olive oil can’t be used for high temperature cooking due to its smoke point, however this has been debunked. Research has instead shown that smoke point is not a reliable indicator of suitability for cooking and that fat profile and antioxidant levels are more indicative of stability10. With its high monounsaturated fat and antioxidant content, extra virgin olive oil can and should be used for all types of cooking including frying, roasting, and baking – making it a highly versatile oil.
While both oils contain predominately healthy unsaturated fats, extra virgin olive oil is far superior when it comes to health benefits, as well as being the more well researched, stable, and versatile of the two oils. Our advice is to use extra virgin olive oil as your main oil in the kitchen and stick to consuming whole or crushed flaxseeds/linseeds rather than the flaxseed oil.
View article references
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5. National Heart Foundation of Australia. Position Statement – Fish, Seafood and Heart Healthy Eating [Internet]. Melbourne VIC, National Heart Foundation of Australia; 2015 [cited 2021 Dec 20] Available from: https://www.heartfoundation.org.au/getmedia/0678aaa5-5828-4cf0-ac35-e34d02bec705/190729_Nutrition_Position_Statement_-_Fish_and_Seafood.pdf
6. Dinu M, Pagliai G, Casini A, et al. Mediterranean diet and multiple health outcomes: an umbrella review of meta-analyses of observational studies and randomised trials. European journal of clinical nutrition 2017; 1: 14
7. Martín‐Peláez S, Covas MI, Fitó M, et al. Health effects of olive oil polyphenols: recent advances and possibilities for the use of health claims. Molecular nutrition & food research 2013; 57: 760-771.
8. Goyal A, Sharma V, Upadhyay N, et al. Flax and flaxseed oil: an ancient medicine & modern functional food. J Food Sci Technol. 2014 Sep;51(9):1633-53. doi: 10.1007/s13197-013-1247-9.
9. Jung, H., et al. (2021). "Oxidative stability of chia seed oil and flax seed oil and impact of rosemary (Rosmarinus officinalis L.) and garlic (Allium cepa L.) extracts on the prevention of lipid oxidation." Applied Biological Chemistry 64(1): 6.
10. De Alzaa F, Guillaume C, Ravetti L. Evaluation of Chemical and Physical Changes in Different Commercial Oils during Heating. Acta Scientific. 2018;2(6):2-11.