ROCHESTER, MINNESOTA. The fatty acid composition of cell membranes is a crucial indicator of overall health and studies have shown that abnormalities in the relative concentrations of essential fatty acids (EFAs) are associated with many common diseases such as diabetes and rheumatoid arthritis. The EFA profile of cell membranes is usually measured in the phospholipid phase of blood plasma.
Researchers at the Mayo Clinic report that patients with IgA nephropathy have an abnormal EFA profile and that this abnormality can be corrected by supplementation with fish oil. Their clinical trial involved 15 patients with IgA nephropathy and 100 controls. All participants had their EFA profile analyzed at entry to the study and at 6 weeks, 6 months, and 12 months following entry. The analyses at baseline indicated that IgA nephropathy patients had significantly less omega-3 fatty acids in their cell membranes (20% less) than did controls. The shortfall in DHA (docosahexaenoic acid) was particularly significant at 25%. The difference in omega-6 fatty acid content between patients and controls was quite small with patients having a shortfall of 4%. The mean melting point of the membrane EFAs in the patients was 19.1 degrees C versus 14.8 degrees C in controls indicating that patients' cell membranes were less fluid than those in the controls.
Supplementation with 6 to 12 grams per day of menhaden oil for a year dramatically increased membrane content of omega-3 fatty acids, specifically DHA and EPA (eicosapentaenoic acid). The content of the main omega-6 fatty acid, linoleic acid, declined slightly at 6 weeks and 6 months, but by 12 months had returned to normal. The content of the omega-6 fatty acid, arachidonic acid, on the other hand, was close to normal at entry, but declined thereafter. This is of particular interest in that arachidonic acid is the precursor for inflammatory eicosanoids while EPA is the precursor for anti-inflammatory eicosanoids.
The researchers also measured protein excretion in the urine and glomerular filtration rate before and after fish oils supplementation. Both are important indicators of kidney function. Protein excretion rate (proteinuria) was markedly decreased and glomerular filtration rate significantly improved following supplementation. The researchers conclude that the treatment of IgA nephropathy should include a balanced and enhanced intake of essential fatty acids.
Holman, RT, et al. Essential fatty acid deficiency profiles in idiopathic immunoglobulin A nephropathy. American Journal of Kidney Diseases, Vol. 23, May 1994, pp. 648-54