Wound healing is a normal bodily process and usually proceeds in four phases — hemostasis, inflammation, proliferation and remodeling — according to Shujuan Guo, D.D.S, Ph.D. If one or more stages are interrupted, wound healing can be impaired. The wound center at Portsmouth Regional Hospital in New Hampshire reports that approximately five million Americans suffer from non-healing wounds, indicating that most are found in people with surgical wounds, pressure ulcers, arterial ulcers, diabetes and venous insufficiency. Guo reports that the cost of treatment for non-healing wounds is greater than three billion dollars per year.
Factors Affecting Wound Healing
The wound healing process is complicated and can be affected by many factors. Guo reports that oxygenation, infection, age, sex hormones, stress, diabetes, medications, obesity, alcohol intake, smoking and poor nutrition can impact on wound healing. It is important to remember that many people with non-healing wounds have more than one of these complicating factors. A complete assessment of each individual is essential for proper wound healing to occur.
Nutrition can help or hinder wound healing. Having a normal nutritional status can decrease your risk of developing a non-healing wound, according to Abby Sauer, MPH, R.D., and Tracy R. Smith Ph.D., R.D. Malnutrition, on the other hand, can increase your risk of developing a wound by 75%. While protein is an essential component of wound healing, there are many other nutrients such as calories, fluid, vitamins, minerals, arginine and glutamine that are crucial for wound healing. Increasing the intake of protein alone may not be sufficient for wound healing.
Protein, Arginine and Glutamine
Protein is composed of amino acids, which are considered the building blocks of the body. According to Guo, a protein deficiency can impair wound healing and can increase the risk of wound infection. Sauer and Smith report that protein is essential for tissue maintenance and repair and that it works in conjunction with other nutrients to build lean body mass. The RDI for protein in a healthy adult is 0.8 to 1.0 grams per kilogram of body weight per day. But, in malnourished people, wound healing requires a protein intake of 1.25 to 1.5 grams per kilogram. Sauer and Smith point out that protein intake above that amount does not show any benefits and may cause dehydration.
Arginine and glutamine are both conditionally essential amino acids. They are both made in adequate quantities by the body under normal conditions; however during wound healing, a dietary source may be necessary. According to Sauer and Smith, arginine helps to build lean body mass, decrease muscle breakdown and increase protein synthesis. Glutamine stimulates collagen synthesis and improves immunity.
For people with non-healing wounds, adequate total calorie intake is crucial in addition to protein. Sauer and Smith report that inadequate calorie intake leads the body to use protein and lean body mass for energy. According to Sauer and Smith, malnourished individuals with non-healing wounds should consume 30 to 35 calories per kilogram of body weight every day to help with proper wound healing.
Fluid, Vitamins and Minerals
Adequate fluid intake is also critical for wound healing. When you don't take in enough fluids, dehydration is possible. Sauer and Smith report that dehydration decreases blood volume and can decrease the nutrient and oxygen supply to tissues, which can prevent wound healing. Total intake should be 9 and 13 cups per day for women and men, respectively.
Deficiencies in certain vitamins and minerals can impair wound healing as well. According to Sauer and Smith, there is currently no research to support specific vitamin or mineral supplementation except in people who are already deficient. A multivitamin is appropriate in most cases when a deficiency is suspected.