How to preserve omega 3 in fish

In this brief guide, we are going to answer the question “how to preserve omega 3 in fish” and discuss the methods used to preserve omega 3 in fish.

How to preserve omega 3 in fish 

The best way to consume omega 3 is by eating marine algae or raw fish. However, due to the risk of commercializing and consuming raw fish, many people prefer to cook it. Long chain polyunsaturated fatty acids (PUFA) are susceptible to oxidation during heat treatments (1).

Omega 3 in fish can be preserved by using the correct cooking techniques and proper storage conditions. 

During cooking: use proper cooking methods such as steaming, poaching, baking, microwaving, and cooking under a vacuum. 

A study compared the effect of different cooking methods on the destruction of omega 3 and omega 6 of four fish species. Of the thermal-processes tested, oven-baking turned out to be the best heat treatment for preservation of all lipid features of the meat, including the PUFA content (1). 

Omega 3 in fish oil supplements can be preserved by storing under the correct environmental conditions.

Omega 3 is a polyunsaturated fatty acid with many health benefits. Omega 3 is destroyed at high temperatures 

Due to the numerous health benefits of omega 3, it is now provided as a supplement. However, we can get the same benefits by cooking and consuming fish correctly.

What destroys omega 3 in fish

  • Incorrect cooking method: Deep Frying and canning are two methods that destroy most of the omega 3 content in fish

Deep-frying: The high temperature used in deep-frying will destroy omega 3 in fish. Among cooking methods, pan-frying seems to be the most harmful procedure for freshwater fish, causing the most significant decrease in PUFA content (1). Deep-frying also introduces unhealthy fats. Deep-frying also increases the calories content of fish. 

Canning: Canning destroys omega 3 in fish because of the different processing techniques involved. Canning is a thermal treatment undertaken to inactivate microorganisms that can be done at 121°C for 15 minutes which is necessary to guarantee good palatability of the fish product. As a result of high temperature, fat may oxidize (2).

  • High temperature: High temperatures are responsible for destroying omega 3  while cooking. Opt for cooking methods that use low heat such as steaming, poaching, and cooking under a vacuum.
  • Incorrect storage conditions: Fresh fish has the highest content of omega 3. Over time the omega 3 content reduces. Freezing will preserve the omega 3 content for a longer time.

How to preserve omega 3 in fish during cooking

  • Steaming: Steaming is generally the best cooking technique to preserve nutrients.

During steaming, fish is kept separate from water so that nutrients remain in the fish without leaching into the water. 

However, a study comparing the effect of different cooking methods on the fatty acid content of salmon showed that, among the ways of heat treatment – steaming, cooking, baking and frying – only frying resulted in statistically significant decrease in the two essential PUFAs contents compare to unfrozen fish (3).

A drawback of steaming is that it doesn’t add much flavor to fish and the fish may taste bland. This can be remedied by adding extra seasonings such as salt, pepper, and spices.

  • Poaching: Poaching also preserved the omega 3 content as well as other nutrients in fish. During poaching, the fish is immersed in a liquid such as stock or water and then baked. Poaching uses a lower temperature than other cooking methods so omega 3 is preserved.
  • Baking: Baking involves the use of dry heat to cook fish. Baking preserves omega 3 in fish better than methods such as microwaving and frying. Using little to no oil will during baking will preserve the omega 3 content. It is better to use healthy oils such as olive oil.
  • Microwaving: Microwaving is a convenient and safe method to cook fish while preserving omega 3. Microwaving is also suitable for preserving the nutrients as it uses a minimal amount of water and has a short cooking time and lower temperature. According to a study, the microwave cooking of striped catfish filets results in an approximately 10% change in the amount of PUFA, including EPA and DHA, whereas the percentages of SFA and MUFA remain unchanged (5).
  • Cooking under a vacuum: Cooking under a vacuum is a french cooking technique originally known as sous vide. During cooking under a vacuum, the fish is placed inside a pouch which is then sealed and heated using a temperature-controlled water bath. Sous vide has proven to be a suitable cooking method to best preserve the nutrients in food, according to research (4).

A very low temperature is used when cooking and the sealed pouch does not allow nutrients to escape, so this is considered a very healthy way of cooking.

The drawback of this technique is that it takes a long time to cook the fish. 

How to preserve omega 3 in fish oil supplements

Fish oil supplements are available that contain the same omega 3 as fish. These supplements can be taken by people who do not have easy access to fish or who dislike the taste of wish. The omega 3 content of fish oil supplements will also degrade if not stored properly. 

To preserve the omega 3 content in fish oil (6):

  • Store fish oil in a cool environment. If you live in a warm climate it is best to store them in the fridge.
  • Store fish oil away from direct sunlight.
  • Seal the fish oil tablets in a ziplock bag and remove the air before for storage. This prevents oxidation.

Benefits of omega 3

Fish contains 2 types of omega 3 fatty acids: docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA).

Cardiovascular diseases are the most frequent causes of death in western countries. The intake of omega 3 PUFAs reduces the incidence and decreases the risk of fatal coronary heart disease or sudden cardiac death. Some of the underlying mechanisms for this protective effect include prevention of arrhythmia, reduction of blood pressure and heart rate, improvement of endothelial function, vascular reactivity and cardiac electrophysiology; and reduced platelet aggregation (1).

Omega 3 fatty acids are crucial to a healthy body. Omega 3 can be gained from both fish and vegetables, but fish has the highest content of omega 3. Eating properly cooked fish at least twice a week will provide a lot of benefits. Long-chain omega 3 PUFAs, especially DHA, which is present at high levels in brain tissue, are significant contributors to brain development and function. Deficiency of omega 3 PUFAs decreases the DHA concentration in the brain and has a negative effect on neural development and visual acuity. Lack of DHA is also associated with disorders of the nervous system, including Alzheimer’s disease, schizophrenia, and depression (1)

Benefits of omega 3 fatty acids include:

  • Lowers blood cholesterol levels. 
  • Reduces the chance of heart attacks and strokes.
  • Helps to control blood pressure.
  • Reduces the likelihood of depression.

Other FAQs about Fish that you may be interested in.

Can you eat Muskie fish?

Can you eat mullet fish?

Can you eat monkfish?


In this brief guide, we answered the question “how to preserve omega 3 in fish” and discussed in depth the main methods used to preserve omega 3 in fish. We also looked at the benefits of omega 3.

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


  1. Schneedorferová, Ivana, Aleš Tomčala, and Irena Valterová. Effect of heat treatment on the n-3/n-6 ratio and content of polyunsaturated fatty acids in fish tissues. Food Chem, 2015, 176, 205-211.
  2. Abraha, Bereket, et al. Effect of processing methods on nutritional and physico-chemical composition of fish: a review. MOJ Food Process Technol, 2018, 6, 376-382.
  3. Gladyshev, Michail I., et al. Effect of way of cooking on content of essential polyunsaturated fatty acids in muscle tissue of humpback salmon (Oncorhynchus gorbuscha). Food chem, 2006, 96, 446-451.
  4. Kathuria, Deepika, Anju K. Dhiman, and Surekha Attri. Sous vide, a culinary technique for improving quality of food products: A review. Trend Food Sci Technol, 2022, 119, 57-68.
  5. Domiszewski, Zdzisław, Grzegorz Bienkiewicz, and Dominika Plust. Effects of different heat treatments on lipid quality of striped catfish (Pangasius hypophthalmus). Acta Scient Polon Technol Aliment, 2011, 10, 359-373.
  6. Shafaat, Kausar, et al. An overview: storage of pharmaceutical products. World J Pharm Pharm Sci, 2013, 2, 2499-2515.