Detrimental effects of an omega-3 fatty acid-enriched diet on wound healing.

The omega-3 fatty acids contained in fish oils have anti-inflammatory effects with potential beneficial clinical applications. However, these same effects may alter wound healing, a process dependent upon an adequate inflammatory response. The hypothesis that a diet enriched with omega-3 fatty acids could be detrimental to wound healing was tested in male rats fed complete diets differing only in their fat composition (17% menhaden oil + 3% corn oil vs 20% corn oil by weight) for 21 days before wounding and for 10 or 30 days after wounding (n = 16 per group). The wounding protocol included a dorsal 5-cm skin incision used for mechanical testing and a 2-cm incision used for subcutaneous polyvinyl alcohol sponge implantation. At 10 or 30 days postinjury, the 5-cm skin wounds were harvested and mechanically tested. The sponges were removed at 30 days and analyzed for collagen content. Food consumption and weight gain were the same in the two dietary groups. No differences in the mechanical properties of the wounds were detectable 10 days after injury. At 30 days, however, wounds harvested from rats fed the menhaden oil diet were significantly weaker than those from corn oil-fed animals. This difference in tensile strength was not explained by differential collagen accumulation, inasmuch as the collagen content of the sponges at 30 days was the same in both groups. Dietary consumption of a diet rich in omega-3 fatty acids may conspire against the quality of wounds by altering the fibroplastic or maturational phases of the healing response.