How DHA Is Vital for the Health of Brain and Mind
Let's take a look at how the brain really works
I'm indebted to Wikepedia for this beautiful drawing
(See overview of Omega-3 fatty acids at http://en.wikipedia.org/wiki/Omega-3_fatty_acid)
The Importance of DHA
The nerve cell shown above is covered by a membrane that plays a vital role in how the nerve cell functions. DHA is a key component of this membrane.
The drawing also illustrates the many junctions a single nerve cell makes with other nerve cells in the brain - at meeting points known as "synapses". Here (seen in the synapse blow-up) chemicals are secreted by the nerve cell that transmit signals to other nerve cells. DHA is especially concentrated in the vast proliferation of synapses that ramify throughout the cortex, or “thinking part” of our brain. We know that deficiency of the omega-3s, and DHA in particular, causes a reduction in the chemicals that transmit signals in these synapses, causing a demonstrable malfunction in some of the key brain pathways.
DHA is also a major component of the myelin sheath, which is wrapped like insulation, around the long processes of nerves (see the other blow up). Integrity of the myelin is of the utmost importance for normal brain function.
Key chemical roles of DHA in the brain
Increases the "fluidity" of the nerve cell membrane
Enhances the activity of membrane-bound enzymes
Modifies the number and affinity of membrane receptors
Modifies the function of ion channels
Modifies the production and activity of neurotransmitters
Modifies signal transduction, which in turn controls the activity of neurotransmitters and neuronal growth factors
It is should be altogether obvious that DHA is a vitally important structural and functional ingredient of the human brain. Since we cannot manufacture enough of it from non-marine dietary ingredients, the only way we can get enough of it is through eating fish, or other marine foods, or through taking a dietary supplement of fish oil or omega-3s.
References and Further Reading
See overview of Omega-3 fatty acids at http://en.wikipedia.org/wiki/Omega-3_fatty_acid
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Yehuda S, Rabinovitz S, et al (2002). The role of polyunsaturated fatty acids in restoring the aging neuronal membrane. Neurobiol. Aging 23: 843-853.
Yehuda S (2003). Omega-6/Omega-3 Ratio and Brain-Related Functions. In Simopoulos AP, Cleland LG (eds). World Rev Nutr Diet, Karger 92: 37-56.
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