Precious Yet Perilous
Written by Chris Masterjohn Phd
September 22 2010 15:02
Extracts:
Even in adulthood, however, dietary fats influence the DHA concentrations of most other tissues. Recent research has shown that our tissues use DHA to synthesize compounds called “resolvins,” which are involved in bringing inflammatory responses to an end when they are no longer needed.51
Sufficient DHA thus allows the immune system to mount a robust inflammatory response against invading pathogens or damaged tissues and to bring the response quickly to an end once the task has been accomplished. Researchers are increasingly discovering that most degenerative diseases involve an element of chronic, low-level inflammation, and the inability to “turn off” important inflammatory processes once they are no longer needed could be part of the problem. DHA deficiency may therefore be at the root of widespread declines in cognitive function, increases in mental disorders and epidemic levels of degenerative disease.
EPA, a precursor to DHA, is an omega-3 fatty acid that accumulates in fish but generally exists in only infinitesimal quantities in mammals and other land animals. Many authors consider EPA an “anti-inflammatory” essential fatty acid, but its “anti-inflammatory” activity is a result of its ability to interfere with arachidonic acid metabolism.
The conversion of arachidonic acid to PGE2 in immune cells is an important initiator of inflammation, but it also turns on the genes necessary for the synthesis of compounds that resolve inflammation, some of which are derived from arachidonic acid and others of which are derived from DHA.52 Providing sufficient DHA to allow the synthesis of the full spectrum of inflammation-resolving compounds is a nutritional approach to inflammation. Providing high doses of EPA that interfere with arachidonic acid metabolism, however, is a pharmacological approach, and it is likely to have many adverse consequences.
