Omega-3 is not a single fatty acid, but a group of polyunsaturated fatty acids. For nutrition, ALA, EPA and DHA are particularly relevant. ALA is found predominantly in plant-based foods. EPA and DHA are found mainly in fish, seafood and algal oil.
For the targeted intake of long-chain omega-3 fatty acids, one question is particularly important: How many milligrams of EPA and DHA are actually consumed?
The human body can convert ALA into EPA and DHA, but only to a limited extent. Therefore, ALA, EPA and DHA should not simply be treated as equivalent under the umbrella term omega-3.
EPA AND DHA ARE WHAT MATTER
When it comes to omega-3 supplements, you will encounter many figures: 1,000 mg of fish oil, 2,000 mg of fish oil per daily serving, or a particularly high total omega-3 content.
For targeted EPA/DHA intake, however, the amount of fish oil is not the decisive reference value. What matters is:
EPA per capsule. DHA per capsule. EPA + DHA per capsule.
Two capsules can each contain 1,000 mg of fish oil and still provide completely different amounts of EPA and DHA. Figures stated per daily serving can also make comparisons more difficult because, depending on the manufacturer, these may refer to one, two, three or more capsules.
EPA and DHA are also at the centre of a large proportion of human research. They are incorporated into cell membranes, influence lipid metabolism and serve as precursors for various lipid mediators. DHA is also found in high concentrations in the brain and retina.
QUALITY REQUIRES MEASURED VALUES
The amount of active ingredients, however, is only the first part of assessing quality. What an omega-3 supplement contains in addition is equally relevant.
For marine oils, analyses for relevant contaminants such as heavy metals, dioxins and PCBs are therefore part of a sound quality control process.
There is an important distinction between “below the legal maximum level” and “below the detection limit”. In the first case, a substance may be measurably present but remains within legal limits. In the second case, the method used did not detect a concentration above its detection limit.
This is why statements such as “laboratory tested”, a quality seal or a certificate of marketability are not sufficient for a detailed quality assessment. What matters are specific measured values.
A complete laboratory report, preferably specific to the batch, should show what was tested, which values were measured and which detection limits were used.
FRESHNESS CAN BE MEASURED
With fish oil, there is another dimension of quality: the oxidation of the fish oil, i.e. how fresh was it after filling? EPA and DHA contain multiple double bonds and are therefore comparatively susceptible to oxidation. Oxygen, light, temperature and storage time can influence oxidation.
One important parameter is the TOTOX value. For consumers, the principle is more important than the calculation: The lower the measured oxidation, the less oxidised the oil was at the time of analysis.
The GOED specification sets a maximum TOTOX value of 26 as a quality limit. A value well below 10 indicates very low measured oxidation. However, there is no universally defined threshold for the term “very fresh”.
It is also important when the measurement was taken. An excellent TOTOX value for the raw oil does not automatically describe the condition of the capsules subsequently sold. Processing, transport, encapsulation and storage all take place in between.
Therefore, a current TOTOX value for the actual batch of the finished product being sold is considerably more informative than a general value for the original raw oil.