People eating different balances of omega-3 and omega-6 nutrients develop predictably different proportions of competing highly unsaturated fatty acids (HUFA) in their tissue lipids. While epidemiological studies have associated wide differences in HUFA balance with disease severity, some clinical studies that did not examine wide differences failed to confirm the association. We examined the degree to which the relative amount of arachidonic acid, the major precursor of omega-6 eicosanoids, differs among people who have widely different dietary intakes of omega-3 and omega-6 nutrients. Gas chromatographic analyses of human blood samples describe the balance among n-3 and n-6 HUFA for different individuals. The proportion of the omega-6 arachidonic acid, from which potent eicosanoids are formed, is not constant. It ranges from 30% to 70% of HUFA while the competing n-3 HUFA range from 60% to 10% of HUFA. Significant differences in clinical outcomes between control and intervention groups have been seen when using dietary interventions that shift the balance of n-3 and n-6 nutrients far enough to create a biologically significant difference in the HUFA balance.

PMID: 26002802

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