Omega-3s Fatty Acids and Mental Health: Part I. Omega-3s and Depression.

Omega-3’s and Mental Health[1]

M. Russell Thomas, PhD

By now, most Americans are aware of a nutrient known as Omega-3.  In fact, it is estimated that upwards of 30 to 50 million Americans may currently be supplementing with an Omega-3 product.  The health benefits of Omega-3s have been well established in a number of domains, most notably heart health[1]^,[2] and its anti-inflammatory properties[3]^,[4].   Of particular interest to me are studies that have emerged over the past 10 to 15 years in the area of mental health.  The purpose of this article is to summarize the empirical data into a brief, information article in order that our readers may understand the benefits and some of the caveats of Omega-3s in order to make informed decisions regarding their health.

THE NERVOUS SYSTEM

Understanding the Nervous System and its needs.  To understand the enormous importance of Omega-3’s in the brain and human body, we must understand a few basic facts about the nervous system.  To understand the nervous system in any level of detail requires a tremendous amount of time and study.  People have devoted lifetimes and careers to the study of the complex interplay of neuronal communications in what we call the Central Nervous System, or CNS and to talk about it in a few paragraphs is a difficult undertaking.  However, that is what I will attempt to do. 

The CNS is comprised of the brain and spinal cord and is involved in virtually every single function in the human body.  It is some of God’s most intricate work!  The CNS is made up of unique cells called neurons.  These neurons carry electrical impulses or messages throughout the body.  They are messages that tell your hand to move, your heart to beat, your temperature to regulate and even your mood to fluctuate.  These neurons are made up and defined by a double layer membrane which forms its walls.  And what is this double layer wall is made of?  Fatty acids.  The walls are essential in the transference of the electrical impulses and messages from one neuron to another.  It is critical that they are healthy in order for the messages to effectively pass through from one cell to another throughout the nervous system.  While I have discussed these mechanisms in more detail and in rather colloquial terms elsewhere (see my book Turbo Charged Childhood, Chapter 7, Brain Goobly-Gook) suffice it to say at this point that various chemicals and substances must be able to pass through the wall efficiently or the system simply will not function as it was designed to do, i.e, there will be negative consequences.  Think of this process as tiny flood gates opening and shutting in order to let the messengers pass through from the inside of the cell to the outside, where it can then cross over to another cell where the flood gates open and allow the messenger in.  And so the process repeats itself.

The question that we must ask is, “what makes these ‘gaits’ function effectively?”  While there are a number of compounds and nutrients important in this process, Fatty acids play a central and critical role.  These fatty acid membranes are maintained by essential fatty acids found in our diet, specifically, Omega-3 fatty acids. 

OMEGA-3s

What we need to know about Omega-3 fatty acids and the CNS.  Again, this is a complex area of study and I don’t mean to be offensive to those who have given careers to the study of such things, but let it suffice right now to say that there are 3 fatty acids:  alpha linolenic acid (ALA), eicosapentaenoic acid (EPA), and decosahexaenoic acid (DHA).  While all 3 serve important functions in the human body and brain, in terms of mental health functions, it appears that EPA and DHA are of the utmost of importance.  In fact, the membranes of the nervous system cells are comprised largely of DHA. 

What else we need to know about Omega-3’s and the CNS.  We begin to see the importance of Omega-3’s when we consider the cell membrane composition, but what we also need to understand is the concept that these are called “essential fatty acids”.  So what does “essential fatty acids” mean?  In essence, it means that they are essential to the human body and that the human body cannot manufacture them on its own or, at least, cannot manufacture ample amounts via its own resources.  The body must rely on dietary sources to provide these materials.  Unfortunately, many studies have documented the inadequate diets, particularly of Westerners.  Simply put, most Americans fall incredibly short of providing their bodies with the proper daily amounts of Omega-3’s.  It is no wonder that the depression rates in America dwarf those of other countries that consume many more times the amount of Omega-3s in their diets.  We will talk about the association between Omega-3s and depression more in just a minute.

What does all of this mean for mental health?  The bottom line is that Omega-3s are incredibly important in mental health and play a key role in numerous mental functions.  We will now take a look at some of the areas of mental functioning that have either well established associations with Omega-3s or are currently under investigation because of their suspected association with Omega-3s.  I will discuss these associations both in terms of mental health diagnosis and specific mental health and/or behavioral functions.

What we need to know about Omega-3s.  The first fact about omega-3s to consider is where they come from.  Omega-3s are found in their richest source in fish.  While omega-3s are also found in some plants, such as flax seed, the do not appear to accomplish the same thing when consumed by the human body.  Therefore, fish, particularly those lower in the food chain, are considered the best dietary source of omega-3s.  The problem for most of us here in America is that we are not a heavy fish-eating nation.  Consider that the incident rates of depression are some 10 times higher in America than in Japan and we begin to see the differences in fish consumption accentuated.  In fact, the average Japanese man or woman consumes fish almost on a daily basis, while the average American consumes fish only a few times per month.  This gives us some idea of the efficacy of omega-3s and the body’s need for these essential fatty acids.

A second fact that we need to know about omega-3s involves safety.  Other than some caveats regarding supplementing omega-3s while using a blood thinner medication such as Coumadine (warfarin), their do not appear to be any other health risks associated with omega-3 supplementation other than questions of contamination.  Specifically, the concern of contamination focuses on the amount of mercury in the omega-3 supplement.  The general rule of thumb is that the warmer the waters from which the fish were harvested, the higher the mercury content.  Fish harvested from colder waters, particularly in the higher Atlantic Ocean regions, are going to be less likely to have the problem of high mercury content.

A third fact that we need to understand about omega-3’s is taste.  Put bluntly, fish oil is nasty tasting and many people have a difficult time managing the flavor, particularly the experience 30 minutes after taking the supplement.  I have personally tried many of the liquids that have tried to mask the fish oil taste with everything from lemon to orange to cream.  While many of these products do a decent job of masking the flavor as you take it, I have not found any of those products to deal effectively with the taste after it is taken.  Inevitably, the fish taste is experienced 15-30 minutes after the product is taken and some of continue up to 6-8 hours.  Other manufacturers put their product in a gel cap which again, is pretty effective to mask the taste when consumed, but many of which provide that backwash of fishy flavor later.  Part of choosing an Omega-3 product and making sure that daily recommendations are consistently met is finding one that you can consistently take and not discontinue because the taste is so bad that even a stray cat wouldn’t down it!

A fourth consideration is absorption.  Perhaps no issue is more important than absorption.  Pharmaceutical companies understand this a pay big bucks to specialists to get their compounds into a form that the body can easily assimilate.  Nutriceuticals have come to understand a simple principle:  a nutrient is no better than its absorption rate.  The problem is amplified when dealing with a fat soluable compound due to their relatively large, bulky size (roughly 20 times that of a water soluable molecule).  Companies do a number of things to improve absorption rates including everything from chewable tablets to enhanced dissolving pills to gel caps to elixir liquids.  While these techniques do improve absorption, rates of absorption with these methods remain low, generally in the 33-40% range.  This means that somewhere between 2/3rds and a half of that product are being flushed down the toilet…literally!

One method to increase absorption that has proven to be very effective is called micellization.  Of all the techniques to improve absorption, micellization has by far demonstrated the most effective way to increase rates.  Studies with Vitamin E, for example, show upwards of 90% absorption[5] verses other formulations.  Pill forms were particularly poor for absorption, weighing in around 25%, give or take a little.  Most Omega-3 compounds are manufacturer in a gel cap and do not use the micellization process.  In fact, as far as I am aware, only one manufacturer uses the micellization process with Omega-3’s[2].  I have personally tried this product and have been quite pleased with both the results and the fact that it is maximizing absorption.  In addition, I have also noted a lack of fish taste both during consumption and afterwards.

DEPRESSION and OMEGA-3s

In terms of mental health, Omega-3s have demonstrated a strong, positive relationship with various forms of depression.  A review of the professional literature yields a plethora of studies that have documented this relationship between Omega-3 consumption and depressive symptoms.  Generally, these studies link increased rates of depression in countries that consume less fish (a major source of Omega-3s) when compared to countries that eat fish at least several times per week.  While this body of literature describing the link between Omega-3s to depression, I will summarize the data that is generally well accepted by the mental health community.

• Abnormally low amounts of Omega-3 polyunsaturaged fatty acids (PUFA) in cell membranes, plasma, etc. specifically, significantly low EPA and DHA are associated with higher depressive symptoms.
• Improvement in depressive symptoms when an Omega-3 supplement is added to medication treatment regimen.
• Omega-3 supplements were well tolerated by patients with only a small percentage reporting even minor gastrointestinal side effects (gas!).
• Supplementing with Omega-3s are deemed to be safe. 

Lower Omega-3 levels have been associated with a number of specific and unique mental health situations involving depressed mood.  For example, low Omega-3 levels were found to be associated with depression in pregnant women and post-partum women[6]^,[7].  This shouldn’t surprise us, as pregnant women are in a unique position of competing with their unborn babies for Omega-3s because the developing baby’s brain requires higher levels of DHA in order to mature properly.  The demand for DHA may leave the expectant mother vulnerable to depression.  Studies have demonstrated positive therapeutic effects on pregnant women including lower depressive symptoms.   

In a very unique study, there is evidence that Omega-3s may be a predictor of suicide risk[8].  Piggybacking on previous studies which established an association between Omega-3s, depression and suicidal tendencies among the depressed, researchers investigated the possibility that lower DHA levels may predict future suicidal behavior.  Following 33 medication-free depressed patients for 2 years, 7 individuals attempted suicide during that timeframe.  They were found to have low DHA plasma levels and an inordinate and higher ratio of Omega 6s to Omega-3s.

Studies conducted with children, although not plentiful, seem to echo the same results found in adults[9].  That is, supplementation with Omega-3s has been shown to be linked with a subsequent lowering of depressive symptoms as measured by both self and others (parents, teachers, etc.).  It is noted that the beauty of these studies is that there were no adverse side effects or reactions reported in these studies with children.

A final word about Omega-3s and Depression.  There has been some confusion about which Omega-3 seems to generate the positive response in depression.  Namely, it was initially thought that DHA, which is rich in the brain and vital in cell membrane activities, was the player of impact.  However, more recent studies, as well as some older, have provided strong evidence supporting the critical role of EPA in the alleviation of depressive symptoms[10].  Additionally, it appears that initially, a larger dose may be beneficial, somewhere in the 2.0 grams range, while on an ongoing basis, say after the first month, 1 gram may be sufficient to generate therapeutic effect[11]^,[12].  Finally, it is noted that Omega-3’s may not be an immediate response.  Most studies observed changes over a number of weeks.  It is generally felt that the brain is assimilating and repairing itself during this time.  It is further noted that many of the antidepressant medications also require a period of time to reach maximum benefit, generally 10-14 days.