Monday, January 31, 2011

Omega-3 deficiency and low dietary omega-3 to omega-6 ratio may exacerbate depression and reduce neuroplasticity

Here's an interesting update on the dietary fatty acid issue, as it pertains to mood disorders and neuroplasticity:

This article, published in Nature Neuroscience (January 30, 2011), is an example of some good research being done by a group at the University of Bordeaux in France.  They demonstrate substantial negative neurophysiological changes in mice as a result of an omega-3 deficient diet.  It is interesting to note that the brain's endocanniboid system is specifically affected by omega-3 deficiency, according to this research.

This is further evidence supporting the importance of attending to a healthy diet, in maintaining optimal mental health.  Omega-3 fatty acids are one element of a healthy diet.  While omega-6 fatty acids are also needed in the diet, these lipids behave to some degree competitively with omega-3.  Therefore,  the ratio of dietary omega-3 to omega-6 is is very important.  Western diets tend to have an unhealthy ratio of these lipids, due to excessive omega-6. 

An ongoing issue of debate has to do with whether plant sources of omega-3 (primarily ALA) are as useful as fish sources (DHA and EPA).  Existing evidence shows that DHA and EPA are more important.  ALA can be converted in the body to DHA and EPA, but the efficiency of this may vary from person to person.

Wikipedia has a nice review of this subject:
but some of the sources are less than ideal.

It is interesting to consider that the DHA/EPA issue is not a "micronutrient" issue.  They could be considered  "macronutrients."  The solid mass of the brain consists mostly of lipids (60-80 % of the non-aqueous mass); DHA and EPA  make up over 10% of this lipid mass, which is a very high concentration.

Here's a link to a paper which quantifies the  high fractions of omega-3 lipids in brain mass:   --this paper also showed that dietary changes substantially altered the proportion of omega-3 lipids in brain tissue


Anonymous said...


I know you commented on this somewhere else on your blog but I can't find it.

If one were to add fish oil to the diet... which kind and how many mgs of EPA and DHA should there be per "serving?" Do you recommend any brands that you trust that can be found in canada?

Keep in mind, I am looking for the cheapest thing that will do the job. (although at the same time I am investigating sardine recipes.)

My problem is I go and investigate this in a supermarket and find there are about 30 different kind, which is a frustration in itself.


GK said...

I'll try to respond in more detail later--but in brief, a typical reasonable dha/epa dose per day would be supplied by three 1-gram fish oil capsules daily (type of fish shouldn't matter much, so you could look for a good deal). This would contain about 900 mg epa + dha combined. Some studies have used twice as high a daily dose or more. With fish oil, freshness should be a strong consideration. If you don't like capsules you can get pure refrigerated fish oil (e.g. one good brand is Nutri-Sea), which can be added to a fruit smoothie or yogurt, etc. as long as you consume it right away & of course don't heat it.