Immunonutrition: Role in Wound Healing and Tissue Regeneration

Abstract

Significance: The role of immunonutrition in wound healing has been an area of both interest and controversy for many years. Although deficiencies in certain nutrients have long been known to impair healing, supplementation of specific immune modulating nutrients has not consistently yielded improvements in wound healing. Still, the prospect of optimizing nutrition to assist the immune system in wound repair bears great significance in both medical and surgical fields, as the costs of wound care and repair cannot be ignored. Recent Advances: Recent studies have rekindled efforts to elucidate the roles of specific immunonutrients, and we now have a better understanding of the conditionally essential role of various nutrients such as arginine, which becomes essential in certain clinical situations such as for the trauma patient or patients at high risk for malnutrition. Immunonutrition in its current formulation usually includes supplementation with arginine, glutamine, omega-3 fatty acids, vitamins, and trace minerals, and its use has often been associated with decreased infectious complications and sometimes with improvements in wound healing. Critical Issues: A key to understanding the role of immunonutrition in wound healing is recognizing the distinct contributions and importance of the various elements utilized. Future Directions: Critical areas for future study include identifying the specific populations, timing, and ideal composition of immunomodulating diets in order to optimize the wound healing process.

Adrian Barbul, MD, FACS

Figure 1.

The time course of the different cells appearing in the wound during the healing process. Macrophages and neutrophils are predominant during inflammation, whereas lymphocytes peak somewhat later and fibroblasts are predominant during the proliferative phase. Adapted with permission from Witte and Barbul. To see this illustration in color, the reader is referred to the web version of this article at www.liebertpub.com/wound

Figure 2.

Schema for the immunological role of various immunonutrients in wound healing. *Some studies suggest that the anti-inflammatory effects of ω-3 fatty acids are beneficial to wound healing, rather than detrimental, as shown (discussed further in text). **Other antioxidants and antioxidant cofactors play similar roles; these have been tested in trials as having an antioxidant effect mediating wound healing. MΦ, macrophage; TNF-α, tumor necrosis factor alpha. To see this illustration in color, the reader is referred to the web version of this article at www.liebertpub.com/wound