Posted by Larry Hoover on June 27, 2004, at 10:13:21
In reply to Fish Oil, posted by Glydin on June 14, 2004, at 8:03:50
> Can someone tell me what is the actually action of Fish Oil in the brain? As in, how does it work with mood & emotional states for improvement?
There are a whole lot of reasons, and I am a little concerned that I will overwhelm with detail....I'll try to keep it simple.
There are two particular fatty acids in fish oil that are linked with beneficial brain effects. They are both omega-3 polyunsaturated fatty acids. One is EPA, and the other, its slightly longer, slightly more unsaturated partner, DHA. They have radically different, but complimentary, effects in the brain.
EPA decreases inflammatory response. What has that to do with mood? We know that depression is associated with disruptions in the immune system, especially increases in immune reactivity. Whether that is cause or effect, we do know that if you get the immune response more normalized, mood tends to go with it. EPA counteracts the effects of another fatty acid that has the same length, but which is an omega-6 fatty acid with one less unsaturated bond (arichidonic acid, AA). The predominant effect of EPA is believed to lie in its dampening of the adverse effect of AA. We get far too much AA in diet, and not enough EPA. In this regard, we are malnourished in EPA.
DHA has more of a direct effect on neuronal behaviour. DHA is a structural component of neuronal membranes. When it is deficient in diet, it is replaced by AA, and the membranes become less fluid. That inhibits receptors from working properly. The brain undergoes general stress from this, having to work harder to accomplish the "desired" response from neurotransmitter release. DHA is also cleaved from membranes under certain events, and it too counteracts the adverse effects of AA release via the same mechanism. If you don't have the DHA to release, you only get the AA effect.
DHA is also linked to changes in genetic regulation of neuron behaviour. There are substantial changes in genes which regulate energy metabolism, membrane protein expression, neuronal plasticity, and other beneficial changes. (See: http://www.pubmedcentral.gov/articlerender.fcgi?tool=pmcentrez&artid=122397, Table 5)
There is substantial evidence that man evolved on a diet that provided an omega-6:omega-3 ratio of about 1:1. Current western-type diets provide an imbalanced ratio of between 30:1 and 200:1. Culturally, we are all omega-3 deficient. This may alone be responsible for the increase in mood disorders in western society.
There is some controversy over whether supplementing with the shorter omega-3 fatty acid alpha-linolenic (e.g. flax oil) is sufficient to overcome the imbalance from diet, as there are five chemical reactions required to convert it to DHA. The yield, the efficiency of that process, has been estimated to be close to zero in men, and no more than 7% in women. Therefore, it is best, IMHO, to use fish oil, as it contains the fatty acids already formed. (There are exceptions, of course. I have a bipolar friend who goes manic on fish oil, but who is stabilized by flax oil. I make no promises.)
There are no concerns about heavy metal contamination of fish oil. Heavy metals segregate out with proteins in the purification process. There is no protein in the purified product (what you buy), so there are no heavy metals, either.
Fish oil confers other major health benefits, such as enhanced cardiovascular health, resistance to the development of Alzheimer's, resistance to certain causes of blindness, resistance to diabetes, reduction of blood pressure, beneficial changes in HDL/LDL cholesterol ratios, and so on.
I will pause here, but I welcome further questions.
Lar
poster:Larry Hoover
thread:356500
URL: http://www.dr-bob.org/babble/alter/20040613/msgs/360942.html