Introduction: We have shown that omega-3 polyunsaturated fatty acids (PUFA) derived from fish oil (FO) was an effective treatment for diabetes vascular and neural complications. However, is FO the best source of omega-3 PUFA for treating diabetic peripheral neuropathy (DPN)?

Methods: To address this question we used a rat model of type 2 diabetes and a late intervention protocol. After 10 weeks of hyperglycemia, diabetic rats were treated for 12 weeks via diet with omega-3 PUFA derived from a variety of sources including menhaden (fish) oil (MO), krill oil (KO), oils derived from algae that produce primarily eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) or combination of EPA and DHA, or commercial ethyl esters of EPA, DHA or combination of EPA and DHA. Primary endpoints were motor (MNCV) and sensory (SNCV) nerve conduction velocity, intraepidermal and cornea nerve fiber density, thermal and cornea sensitivity, and vascular reactivity of epineurial arterioles that provide circulation to the sciatic nerve. The omega-3 index, and serum fatty acid levels were also determined.

Results: The dose of each omega-3 PUFA supplement was customized to create a healthy omega-3 index. Defined as the sum of EPA and DHA as a percentage of total fatty acids in red blood cells, range for healthy level 8 - 12%. Following 22 weeks of untreated diabetes neural and vascular endpoints were significantly impaired compared to control rats. Treatment with MO provided the greatest improvement for all neural endpoints followed by KO and algal oils or ethyl esters containing a combination of EPA and DHA. Algal oil or ethyl ester of EPA alone was the least effective. The greatest improvement in vascular reactivity of epineurial arterioles to acetylcholine was realized following treatment with MO with less benefit from the other omega-3 PUFA sources.

Conclusion: These pre-clinical studies suggest that in a clinical trial for DPN the best outcome may be obtained by using FO as the source for omega-3 PUFA.


M.A.Yorek: Consultant; Novo Nordisk.


U.S. Department of Veterans Affairs (RX003826-01)

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