Omega-3 Index

Category: Integrative Nutrition

Learn how the omega-3 index affects cardio vascular and brain health

What are essential fatty acids?

Essential fatty acids are the healthy fats that the body needs and is not able to synthesize so they must necessarily be incorporated in the diet. The fatty acids α-linolenic acid (18:3, precursor of the AGPI-ω3) and linoleic acid (18:2, precursor of the AGPI-ω6) are considered essential. The diet must contain them in adequate proportions because their lack or imbalance in the intake can cause serious metabolic disorders.

Among the foods rich in omega 3 we find oily fish (tuna, salmon), algae, flax seeds, pumpkin seeds and chia.

On the other hand, among the foods high in omega 6 we have sunflower oil, avocado, seeds and nuts.


Of the ω3 line, the most relevant polyunsaturated fatty acids (PUFA) are EPA and DHA which, although they are not essential, their low conversion efficiency has led them to be considered as such. (1)

  • In men: 8% of α-linolenic acid (ALA) is converted to EPA and 0-4% to DHA.
  • In women: 21% of α-linolenic acid (ALA) is converted to EPA and 9% to DHA.

The elongase and desaturase enzymes used in the metabolic pathways of omega-3 and 6 acids are common and competitive. The elongase and desaturase enzymes used in the metabolic pathways of omega-3 and 6 acids are common and competitive. When there is more omega-6 substrate than 3, the conversion of α-linolenic acid (ALA) to its derivatives EPA and DHA is greatly reduced, increasing the synthesis of arachidonic acid (AA) and thus the inflammatory response.

For proper health, the omega-6: omega-3 ratio should be around 4:1, but unfortunately the new lifestyle has changed eating habits and the standard western diet has an average ratio of 15:1. This imbalance in favour of omega-6 could be the cause of many diseases related to immune response and inflammation. (2)

An adequate intake of omega-3 fatty acids helps to preserve health and prevents the development of diseases.

WHO and FAO recommend 1000 mg/day of omega 3. In Spain, this consumption is 100 mg/day on average.

The PUFA-ω3 are part of the membrane phospholipids and have functional and metabolic effects. On the one hand, they increase the permeability of the cell membrane offering more elasticity and plasticity to the cells, which translates into a greater input of O2 and nutrients and output of waste.
On the other hand, they not only act as precursors in the synthesis of eicosanoids and docosanoids but also regulate the expression of various genes involved in the control of inflammatory processes, cognitive functions, vascular homeostasis and platelet aggregation. They are also attributed with favourable effects on the lipid profile (decrease in triglycerides and VLDL cholesterol, possible increase in HDL cholesterol) and hypotensive properties. (3)


The Omega-3 index is an excellent tool to determine the risk of suffering from cardiovascular and brain diseases. It evaluates the presence of EPA and DHA provided both through food and endogenous synthesis.

This index calculates the percentage of EPA and DHA as a percentage of the total fatty acids present in the red blood cell membrane. A low omega-3 index is correlated with an increased risk of suffering a cardiovascular or cerebrovascular event. It is considered an acceptable level from 6-7% and optimal more than 8%. (4)


Elevated risk of a cardiovascular or cerebrovascular event

Very increased risk of neurodegenerative diseases.

Very high predisposition to depression.

Significantly increased risk of cardiovascular or cerebrovascular accidents.

Some risk of suffering from degenerative brain diseases.

Significant predisposition to depression.

Very low predisposition to a cardiovascular or cerebrovascular event

Very low probability of suffering neurodegenerative diseases.

Very low predisposition to depression.

Omega-3 index applications

  • Cardiovascular diseases
  • Depression
  • Pregnancy
  • Hyperactivity and inattention
  • Sport

How can I increase my omega-3 index?

A good start to increasing the omega-3 index would be to restore the omega-6/omega-3 balance by reducing consumption of processed foods and excess vegetable oils in favour of a more natural omega-3 enriched intake. However, when we consume omega-3s, they must be transformed into longer chain acids (EPA and DHA) to have a beneficial effect on our health. Since their bioavailability in food is very limited and many people lose the ability to transform the omega-3 precursor (α-linolenic acid) into its derivatives with age and unhealthy lifestyles, we must resort to supplementation to ensure a high omega-3 index.

Which omega 3 supplement should I take?

Not all Omega-3s are the same, so when choosing a supplement, you have to take into account the source, the concentration of DHA in relation to EPA and the method of extraction and purification (free of toxins).

Although EPA is more commonly consumed, clinical studies indicate that administering pure DHA provides a higher % of omega-3 to the body than when administering a mixture of EPA+DHA (3:2). (5) Therefore, EPA acts by inhibiting the absorption and bioavailability of DHA in the body. On the other hand, DHA decreases the level of triglycerides in the blood to a greater extent than EPA, (6) favouring circulation and preventing platelet aggregation and thrombus formation.

DHA accumulates and concentrates in three target organs: brain, retina and gonads.

In addition, DHA generates protectins and resolvins of the D series, such as NPD1, whose anti-inflammatory capacity is significantly superior to those of the resolvins of the E series derived from EPA. Therefore, it is concluded that DHA has a greater cardioprotective capacity than EPA and DHA when administered together.

Mederi Laboratories has a high purity DHA (76% min. DHA, 5% max. EPA), obtained by supercritical CO2 technology, free of phytanic acid, with a very high bioavailability and safety, which guarantees the necessary and daily absorption of omega 3 in the body. One pearl per day (1000 mg of DHA) is the ideal dose for healthy people who wish to preserve cognitive, visual and fertility function, in addition to improving the Omega 3 index.


  1. Aterburn-LM et al. Distribution, interconversion, and dose response of n-3 fatty acids in humans. Am J Clin Nutr, 2006; 83 (suppl):1467S-76S.
  2. Simopoulos AP. The importance of the ratio of omega-6/omega-3 essential fatty acids. Biomed. Pharmacother. 2002; 56(8):365-379.
  3. John H. al. Omega-3 Fatty Acids for Cardioprotection. Mayo Clin Proc. 2008, 83 (3), 324-332.
  4. Harris WS. Omega-3 fatty acids and cardiovascular disease: A case for omega-3 index as a new risk factor. Pharmacological Research, 2007; 55: 217-223.
  5. Allairea, J. et. al. Supplementation with high-dose docosahexaenoic acid increases the Omega-3 Index more than high-dose eicosapentaenoic acid. Prostaglandins, Leukot, Essent. Fatty Acids, 2017, 120, 8–14.
  6. Innes J.K. et al. The Differential Effects of Eicosapentaenoic Acid and Docosahexaenoic Acid on Cardiometabolic Risk Factors: A Systematic Review. Int. J. Mol. Sci. 2018, 19, 532-524.
Laboratorios Méderi Nutrición Integrativalogo-méderi

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