Wound healing is the process of repair that follows injury to the skin and other soft tissues. Wounds may result from trauma or from a surgical incision. We may also consider pressure ulcers (also known as decubitus ulcers) as wounds. The capacity of a wound to heal depends in part on its depth, as well as on the overall health and nutritional status of the patient.
Following injury, an inflammatory response occurs and the cells below the dermis (the deepest skin layer) begin to produce collagen. Later, the epithelial tissue (the outer skin layer) is regenerated. Dietary modification and nutritional supplements may improve the quality of wound healing in two ways: Firstly by influencing these reparative processes, and secondly by limiting the damaging effects of inflammation.
Symptoms include: Swelling, stiffness, tenderness, discoloration, skin tightness, scabbing, itching, and scar formation.
Dietary changes: The underlying tissues of the skin are made of protein. Therefore, the patient requires an adequate amount of calories and protein to build and repair the tissues.
While major wounds from extensive injuries or surgery significantly raise the protein and calorie requirement, the optimal healing of minor wounds should not require changes from a typical healthy diet. (1)
In a study of malnourished people with skin ulcers, those who were given a diet containing 24% protein showed a significant reduction in the size of the ulcer. On the other hand, those given a diet containing 14% protein showed no significant improvement. (2) This study suggests that an increase in dietary protein can improve wound healing in malnourished people. It may well be that the same benefit would be observed in well-nourished people.
Casein is a milk protein and has the ability to form a gel or clot in the stomach. This ability makes it very efficient in nutrient supply. The clot is able to provide a sustained slow release of amino acids into the blood stream, sometimes lasting for several hours. (3) Casein is a good source of essential amino acids, predominantly glutamic acid. It also contains proline, aspartate, leucine and lysine, which are necessary for wound healing.
Whey protein is an excellent protein choice for all ages. It provides a number of benefits in areas including sports nutrition, weight management, immune support, bone health, and general wellness. Whey protein provides the highest value of BCCAs (branched chain amino acids), which is important for healing and regeneration. Other benefits of whey include the fact that it is easily absorbed which helps to increase lean muscle mass. (4) This is necessary for quicker wound healing.
Preliminary and controlled studies of people with severe burns and other types of injuries (5) showed that supplementation with 10 to 30 grams of ornithine alpha-ketoglutarate (OKG) per day can significantly improve wound healing and decrease the length of hospital stay. Improved healing from major trauma and surgery has also been demonstrated with oral supplements including several grams of glutamine per day. (6)
Arginine supplementation increases protein synthesis and improves wound healing in animals. Two controlled trials have shown an increased tissue synthesis in surgical wounds in people given 17 to 25 grams of oral arginine per day. (7) (8)
Glucosamine sulfate and chondroitin sulfate may both play a role in wound healing by providing the raw material need by the body to manufacture the connective tissue found in skin, tendons, ligaments, and joints. Results of research on the value of oral supplements of glucosamine or chondroitin for wound healing are also awaited. Caroline is a small molecule composed of the amino acids histamine and almandine. The exact biological role of Caroline is not completely understood, but animal research demonstrates that it promotes wound healing. More research is warranted in this area.
Thiamine (Vitamin B1), Pantothenic acid (Vitamin B5), and other B vitamins (9) have all been shown to play a role in wound healing in animal studies. For this reason, medical practitioners recommend a high-potency B vitamin supplement to promote wound healing.
Vitamin C is needed to make collagen (connective tissue). It helps to strengthen skin, muscles, and blood vessels, and it also ensures proper wound healing. Severe injury appears to increase Vitamin C requirement and consequently Vitamin C deficiency causes delayed wound healing. A combination of 1 to 3 grams per day of vitamin C and 200 to 900 mg per day of pantothenic acid has produced minor improvements in the strength of healing skin tissue. (10)
Vitamin A plays a central role in wound healing, yet the effect of supplemental vitamin A in people who have suffered a minor injury and are not Vitamin A-deficient remains unclear. Vitamin A supplements have been shown to be especially useful in a topical ointment for skin injuries in people taking corticosteroid medications. (11) Although there are no studies based on humans, some doctors recommend 25,000 IU of vitamin A per day, beginning two weeks prior to surgery and continuing for four weeks after surgery.
Animal studies have shown that vitamin E supplements can decrease the formation of unwanted adhesions following a surgical wound. In addition, wound healing was more rapid in animals fed a Vitamin E-rich diet than in those fed a standard diet.
Many enzymes, including some that are needed to repair wounds, are composed of Zinc. Even a mild deficiency of zinc can interfere with optimal recovery from everyday tissue damage, as well as from more serious trauma. One controlled trial found that the healing time of a surgical wound was reduced by 43% with oral supplementation of 50 mg of zinc (in the form of zinc sulfate) three times per day.
Copper is a required co-factor for the enzyme lysyl oxidase, which plays a role in the cross-linking, and strengthening of connective tissue. Other trace minerals, such as manganese, copper, and silicon, are known to be important in the biochemistry of tissue healing. However, there have been no controlled trials to explore the effect of oral supplementation of these minerals on the rate of healing.
Though numerous factors are known to be important in wound healing, the only supplements that have had a documented beneficial effect on it are certain amino acids, proteins like whey and casein, and water soluble vitamins (Vitamin B complex and Vitamin C).