EPA to DHA Ratio Recommendation September 07 2012

Q: What is the best ratio of EPA to DHA in an Omega-3 supplement?

A:

Both EPA and DHA are critical to the functioning of our bodies. Both can be said to be essential nutrients; that means that we must consume them because our bodies won’t make them*.

Both marine fatty acids EPA and DHA have some overlapping and some unique roles.

DHA has more of a structural role as a building blog of the cell membranes of brain and eyes. That is the reason why consumption of DHA is emphasized for pregnant and lactating women.

This is not to say that other cells in our bodies do not need EPA and DHA. Every cell in our body requires both EPA and DHA. Both are built into cell membranes. When the dietary intake of EPA and DHA is insufficient, the cells will use Omega-6 (pro-inflammatory impact) and/or saturated fatty acids (make cell membranes inflexible and do not let nutrients in) to build its membranes.

Further, both EPA and DHA have slightly differing functional roles:

  • EPA and DHA are necessary for the gene expression. They interact directly with DNA as well as with proteins that affect the processing of transcription factors;
  • An extension of the gene expression effect worthy of stating separately is the fact that DHA produces an epigenetic signal that turns on the BDNF (brain derived neurotrophic factor) gene, and the latter activates neurogenesis and neuroplasticity in the brain;
  • EPA is a precursor of a certain type of prostaglandins, which are hormone-like compounds that serve as catalysts and mediators for a large number of physiological processes within cells and tissues. For example, prostaglandins derived from EPA counteract pro-inflammatory prostaglandins derived from Omega-6. Counteracting pro-inflammatory Omega-6 acids is of a particular importance considering that the ratio of Omega-6 to Omega-3 in modern human diet exceeds up to 10-15 fold the ratio of these two acids, on which humans evolved;
  • Both EPA and DHA participate in modulation of molecules and enzymes participating in various signal transduction pathways in the functioning of cells, tissues, and organs. The pathways impacted by the Omega-3s are numerous and interactive, and the Omega-3 health effects may be due to multiple interrelated mechanisms.

 

To conclude, EPA has slightly more of functional role, and DHA –slightly more of a structural role; and we need both.

As for the precise ratios of EPA and DHA, the rule of thumb that one wants to follow with any nutrients, food or dietary supplements is to follow the path of nature. Our ancestors ate fish. The tables with the EPA and DHA content of various fish species in this article show that EPA to DHA ratio varies in fish between 1-to-2 to 2-to-1.

And that natural ratio is consistent with the only authoritative pronouncement of health authorities on the recommended EPA to DHA ratio -

In 1999 the Workshop on the Essentiality of and Recommended Dietary Intakes (RDIs) for Omega-6 and Omega-3 Fatty Acids was held at The Cloisters, National Institutes of Health (NIH) in Bethesda, Maryland, USA. The workshop was sponsored by a number of scientific organizations and had international experts invited. The working group concluded that there are good data to make recommendations for Adequate Intakes (AI) for healthy Adults; that recommendation is 650 mg of EPA and DHA per day with at least 1/3 coming from either EPA or DHA. In other words, a recommended EPA:DHA ratio is from 2:1 to 1:2.

 

 

*  Conversion to EPA and DHA from the parent ALA fatty acid is limited to about 5%