Ever since James V. Donadio's 1999 paper in the "Journal of the American Society of Nephrology" showed that certain omega-3 fatty acids found in fish oil retard the progression of IgA nephropathy, kidney patients have been excited about the possibility of a new treatment to augment traditional ones. While the jury is still out on the benefit of omega-3 fatty acids, the results look so promising that many nephrologists routinely recommend them to patients with chronic kidney disease.
Definitions
Omega-3 fatty acids are essential fatty acids. The body does not make these so you must get them in your diet or in supplements. The particular omega-3 fatty acids that may be helpful to kidney patients are eicosapentaenoic acid and docosahexaenoic acid, called EPA and DHA respectively.
Doses
Donadio gave his research subjects 1.9 g of EPA and 1.4 g of of DHA. Although both these omega-3's are found in fish and flaxseed oil, the only way to get a dose this high is by taking fish oil. If you follow such a regimen, double check the EPA and DHA content found on the label because the DHA and EPA content in fish oil varies widely. Also double check the serving size because some manufacturers claim that a serving of fish oil is two capsules. Many kidney disease patients take 12 g of fish oil daily.
Controversy
As of 2011, Donadio's results have not been replicated. While anecdotal reports such as the one published by Lavjay Butani and Joann Palmer in the 2000 issue "Nephrology Dialysis Transplantation" have been favorable, there have been no large, long-term studies. "Cochrane Reports" have reviewed 16 small studies on the use of fish oil in transplant recipients. The authors concluded there "was not enough information to show any benefit in preventing heart disease or reduction in kidney function" and that "larger, better studies are needed before regular use of fish oil can be recommended."
Warning
Don't confuse cod liver oil with fish oil. These are very different products with different nutrients. Cod liver oil is so high in vitamin A that it could be toxic if taken in the doses customarily used by kidney patients. These are very different products from very different sources. Cod liver oil comes from the livers of cod fish. Fish oil is made from oil expressed from the entire fish body. Unlike cod liver oil, which raises concerns about contamination with polychlorinated byphenyls, or PCBs, regular fish oil raises less of a problem.
References
- Foundation for IgA Nephropathy: Fish Oil
- "Journal of the American Society of Nephrology;" The Long-Term Outcome of Patients with IgA Nephropathy Treated with Fish Oil in a Controlled Trial; J. V. Donadio; Aug. 1999
- University of Maryland Medical Center: Omega-3 Fatty Acids
- "Cochrane Reviews;" Fish Oil for Kidney Transplant Recipients; A.K.H. Lim, et al.; April, 2007
- "Nephrology, Dialysis, Transplantation;" Effect of Fish Oil in a Patient with Post-transplantation IgA Nephropathy; Lavjay Butani and Joann Palmer; 2000
- National Kidney Foundation; Fish Oil for IgA Nephropathy?; March 2009
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