What fish oil contains

Fish oil. Two words that are nowadays almost synonymous with a healthy lifestyle. Most of us know that its strength lies in its omega-3 fatty acid content, especially EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), which are key to heart, brain and eye health. We buy supplements thinking that we are giving our bodies the best of the marine world. But what if we told you that the contents of a capsule are much more complex? That there is no such thing as fish oil and that quality is absolutely crucial to its effectiveness?

In this article, we'll delve deeper beneath the surface and take a look at what's really in fish oil supplements with the help of scientific studies. We won't rely on marketing claims, but on hard data from peer-reviewed scientific publications. The goal is for you as a consumer to make informed decisions about your health.

Article Content:

• Ingredients are not just about Omega-3: A diverse mosaic of fats
• The Hidden Threat: Oxidation and excess saturated fat
• Why is oxidized oil a problem? A double whammy against your health

Composition isn't just about Omega-3: A varied mosaic of fats

The first thing to realize is that fish oil is not a pure, isolated omega-3 fatty acid. It's a complex mixture of different types of fats, primarily in the form of triglycerides. Think of a triglyceride as a little "structure" where three different fatty acids are attached to the basic backbone (glycerol). And it is the type of these fatty acids that determines the properties and quality of the whole oil.

A scientific study published in PubMed looked at the detailed analysis of triglycerides in different types of fish oils¹. Using an advanced chromatographic method (which is essentially a very sophisticated technique for separating complex mixtures), the researchers found that the fatty acid profile varies dramatically depending on the species and part of the fish from which the oil is extracted.

For example, cod liver oil or monkfish liver oil had similar compositions. In contrast, oils from the body of fatty fish such as mackerel, herring or capelin (a type of small marine fish) showed a completely different and characteristic profile. The study revealed that some fish oils, such as those from anchovies or sardines, contain a much higher proportion of highly unsaturated triglycerides - the ones that carry the most highly valued omega-3 fatty acids.

What does this mean for us? That the origin of the oil is extremely important. It doesn't matter if the oil is derived from cod liver or from whole anchovy bodies. Each source provides a unique cocktail of fatty acids. In addition to the famous polyunsaturated omega-3s (PUFAs), fish oils contain monounsaturated (MUFAs) and even saturated fatty acids (SFAs). And this is where we come to the first potential problem.

The hidden threat: oxidation and excess saturated fat

While the presence of small amounts of various types of fats is natural, a second, more recent study brings up some disturbing findings about commercially available dietary supplements². This research looked at the three best-selling brands of fish oil in the US and compared them to prescription omega-3s. The results were surprising.

The dietary supplements analyzed turned out to contain more than 30 different fatty acids. Of these, up to 36% were saturated fatty acids. This is considerably more than a consumer would expect when buying a product primarily for omega-3s. But the main problem lay elsewhere - in oxidation.

Oxidation is a process we all know from the kitchen. It's the reason why an apple turns brown in the air or why oil in a pan starts to smell and 'rancid' after a while. Polyunsaturated fatty acids such as EPA and DHA are very susceptible to oxidation because of their chemical structure. They can literally 'spoil' on contact with air, light or heat.

This degradation process not only destroys valuable omega-3s, but also creates new, potentially problematic substances - oxidised lipids. The study found that the levels of both primary and secondary oxidation products in the dietary supplements tested exceeded the maximum limits set by international quality standards. In contrast, the prescription product met these standards.

Why is oxidized oil a problem? A double blow against your health

You may be thinking that a little "rancid" fat can't hurt. But scientists have shown that it's not that simple. Oxidation has a double negative impact:

1. It reduces potency: you buy a product for the benefits of omega-3s, but when those fatty acids are oxidized, their positive properties are lost.
2. It can be counterproductive: The study went one step further. In laboratory conditions, researchers tested the ability of omega-3s to protect "bad" LDL cholesterol from oxidation, one of the key mechanisms for their protective effect on blood vessels. They found that pure, unoxidized omega-3s were able to provide this protection with more than 95% effectiveness. However, a mixture of oxidized and unoxidized omega-3s, isolated directly from commercial dietary supplements, failed in this test.

In other words, oxidized fish oil not only fails to provide the expected benefits, but may even interfere with the biological processes we are trying to support. You are paying for something that at best doesn't work and at worst can be a burden on the body.

Conclusion: quality is not a luxury, but a necessity

What can we take away from these scientific findings? First and foremost, that when choosing a fish oil supplement, awareness and attention to quality is absolutely essential.

1. The origin and composition vary: There is no fish oil like fish oil. Oils from different species of fish have different compositions and it is a good idea to prefer those from small, oily fish that are rich in highly unsaturated fatty acids¹.
2. Oxidation is a real enemy: Many commercially available products on the market may contain oxidised oil that does not meet international quality standards and lacks biological efficacy².
3. Price should not be the only criterion: a cheap product can end up being expensive if it is made from low-quality, oxidised raw material that does nothing for your health. Investing in a product from a reputable manufacturer that guarantees freshness, purity and low oxidation (often backed by third-party certifications) is an investment in your health.

When buying, ask about the origin of the oil, the processing methods, and testing for purity and oxidation. Your body deserves the best - not just an empty promise in a shiny capsule, but real, biologically active, pure power from the depths of the ocean.

Sources:

• ¹ Ackman, R. G. (1992). A study of the composition of fish liver and body oil triglycerides. Lipids, 27(8), 624-627.
• ² Mason, R. P., & Sherratt, S. C. (2017). Omega-3 fatty acid fish oil dietary supplements contain saturated fats and oxidized lipids that may interfere with their intended biological benefits. Biochemical and Biophysical Research Communications, 483(1), 425-429.