Trauma and Wound Healing

The Therapeutic Role of Nutrition

The hypermetabolic effects of stress may require special or high-dose nutrients for enhanced wound healing and uneventful recovery. The nutrients affecting the wound healing process include arginine, glutamine, inositol, choline, carnitine, alpha lipoic acid, and coenzyme Q10 (Patel GK 2005)

Arginine. Arginine fuels the cellular immune response and fights against bacterial challenges. It is an essential precursor to protein synthesis at the wound site and increases local wound immune function. Researchers have found that in the case of trauma and surgery, arginine requirements increase to 17 to 25 g of oral arginine per day, in contrast to the usual 5 g per day (Barbul A et al 1991; Kirk SJ et al 1993). Enhanced wound healing has been observed with large doses of arginine (Patel GK 2005).

Glutamine. Glutamine is a key substrate for fast-growing and multiplying cells, including white blood cells. Glutamine stimulates the proliferation of fibroblasts, thereby helping in wound closure. It is the major amino acid lost during any tissue injury, implying that it has a significant role in the preservation of lean body mass. According to researchers, glutamine possesses anabolic properties. These properties are effective in wound healing only when present in amounts 2 to 7 times greater than required in healthy persons (Roth E et al 1990).

Bromelain. Bromelain is a proteolytic enzyme derived from pineapple stem. This anti-inflammatory enzyme possesses the ability to break down or dissolve proteins. This property can be utilized to reduce muscle and tissue swelling, especially following injuries or surgery (MacKay D et al 2003). Use of oral bromelain over the postoperative period results in faster resolution of swelling and decreased dependence on analgesics in fracture patients (Kamenicek V et al 2001). Similar results have been recorded after dental surgery (Tassman G et al 1964) and musculoskeletal trauma (Masson M 1995).

Glucosamine. Glucosamine provides the raw material needed to repair the connective tissue found in skin, tendons, ligaments, and joints (McCarty MF 1996; Zupanets IA 2002). Animal studies show that levels of glucosamine increase in injured tissue during healing (Lehto M 1985). Although human studies on the effect of glucosamine during wound healing have not yet been published, recent reviews of perioperative nutrition recommend glucosamine 1500 mg daily until healing is complete (MacKay D et al 2003).

Aloe vera. The healing properties of aloe vera have been known for centuries. Used as a topical application, aloe stimulates collagen synthesis and has been shown to promote wound healing (Chithra P et al 1998a). Animal studies have demonstrated beneficial effects of aloe vera in healing frostbite, electrical injuries, and diabetes (Miller MB et al 1995; Chithra P et al 1998b; Davis RH et al 1987; Davis RH et al 1988). Aloe vera improves the permeability of cell walls, boosts nutrient influx into the cells, and removes toxins from the cells (Vogler BK et al 1999).

Curcumin. An extract of the spice turmeric, curcumin is used to reduce inflammation and treat wounds and skin ulcers. Research shows that it has antioxidant properties and other health benefits (Nirmala C et al 1999). It also improves the formation of new skin and the migration of immune cells that are necessary for healing at the wound site (Sidhu et al 1999). Specifically, it has been shown to enhance muscle regeneration in muscle injury (Thaloor D et al 1999).

Omega-3 fatty acids. Omega-3 fatty acids, including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are anti-inflammatory and have wide-ranging effects. They stimulate the immune system by enhancing T-cell and natural killer cell activity. Because the body's need for fats increases under conditions of stress, the omega-3 fatty acids play an important role in the healing process.

Boosting Growth Factors

Growth factors are small proteins that enable cells to communicate. There are seven major growth factor families: epidermal growth factor, transforming growth factor-beta, insulin-like growth factor 1, interleukins, platelet-derived growth factor, fibroblast growth factor, and colony-stimulating factors.

Growth factors have a number of functions in wound healing (Steenfos HH 1994):

• Forming granulation tissue
• Increasing connective tissue by creating new blood supply
• Promoting remodeling and growth of new skin
• Attracting proteins and immune cells to fight infection

Studies have shown that various growth factors are diminished after trauma. For instance, serum levels of insulin-like growth factors are decreased during critical illness (Timmins A et al 1996). Nutrients that stimulate the secretion of growth factors may assist recovery from trauma. Various supplements have been studied for the ability to boost growth factors, including the amino acid arginine, omega-3 fatty acids, and nucleotides (Daly JM 1992).

Arginine, a semiessential amino acid, helps in wound healing and recovery from stress. In addition, arginine enhances the immune response of trauma patients. In a study of healthy people and surgical and intensive care unit patients, arginine was shown to increase lymphocyte and monocyte proliferation and to enhance helper T cell formation (Kirk SJ et al 1990). Arginine also increases intestinal calcium absorption and collagen synthesis.

Ornithine alpha-ketoglutarate (OKG) is a salt formed of two molecules of ornithine and one molecule of alpha-ketoglutaric acid. OKG is a promising anticatabolic agent that promotes wound healing and protein synthesis. Researchers have hypothesized that OKG works by upregulating glutamine and arginine production (Cynober L 1991).

Glutamine supplementation in critically ill patients has been shown to improve gut-associated lymphoid tissue function and enhance the immune defense against infection (Jones C et al 1999).