As the apt cliché goes, “food is medicine.” It is undeniably true that when a patient eats a balanced diet and has a healthy appetite, food can provide all of the ingredients that constitute good health. However, food only serves as medicine if it is consumed, and there are many factors involved in an individual’s willingness or ability to consume a well-balanced diet. Unfortunately, obtaining, preparing, and consuming enough nutritious food on a daily basis to support optimal wound healing can present a challenge to some patients — especially those who live with diabetes. This leads to some obvious questions that are often asked of registered dietitian nutritionists (RDNs): Are supplements necessary to support wound healing? Can supplements be harmful? Should supplemental nutrition be part of wound care protocol? This article will help wound care providers in the outpatient setting answer these questions.
Nutrients fall into two categories: macronutrients (protein, carbohydrates, fat) and micronutrients (vitamins and minerals). Water, which is sometimes considered a macronutrient, is often referred to as the “forgotten nutrient.” Although few would argue that water is essential to good health, it is often overlooked during conversations about one’s nutritional needs. There is no doubt that all nutrients are needed to support cells, tissues, organs, and body systems. What is less clear is exactly which nutrients are critical to wound healing and whether dietary supplements of those nutrients (as opposed to food sources) can improve wound healing. Most of what is known about nutrition and wound healing comes from knowledge about the role that specific nutrients play in the wound healing process rather than definitive evidence that identifies specific nutrients required for wound healing. This is an important distinction that is sometimes overlooked by clinicians who are eager to heal a chronic wound.
NUTRITION 101: MACRONUTRIENTS
Protein, carbohydrates, and fat all provide calories (ie, energy). Appropriate amounts of these macronutrients can help meet the body’s energy needs and provide the combination of energy sources required to maintain weight, maintain lean body mass, and maximize wound healing. An individual’s macronutrient needs are based on his or her weight. For that reason, a 100-pound woman needs less food than a 195-pound man. Most foods contain some combination of protein, carbohydrates, and fat. For example, meat contains protein and fat while dairy contains protein, carbohydrates, and fat. Most foods that provide calories also offer vitamins and minerals. The exception to that rule is food that is typically referred to as having “empty calories” (ie, foods that contain calories but few or zero nutrients). Protein is thought to play a significant role in wound care; it is responsible for repair and synthesis of enzymes involved in wound healing, cell multiplication, and synthesis of collagen and connective tissue.1 Also, increased dietary protein has been linked to improved healing rates.2,3 Dietary protein is composed of amino acid chains. Some amino acids are indispensable (needed in the diet) while others are dispensable (manufactured in the body). Some amino acids, specifically glutamine, cysteine, and arginine, become conditionally indispensable (meaning they are needed in the diet) when the body is under stress. This is one reason that supplements containing arginine are sometimes recommended for patients who are living with chronic wounds. Water (sometimes considered a macronutrient) is calorie-free and is found in a variety of liquids, some of which are nutrient-dense (eg, milk). Others, such as soda or fruit punch, are empty calories. Water is also found in foods, and, by one estimate, foods provide about 20% of our fluid needs.4 (Soup and watermelon are two foods that are high in water.) Unintended weight loss is one important way to identify if macronutrient needs (including fluid) are being met. For this reason, routine weight checks for patients (at each office visit for community-dwelling patients; at least monthly for those residing in institutional living) are critical to help identify an insufficiency in caloric and/or protein and fluid intake. If an individual’s protein, calorie, or fluid needs aren’t met through diet alone, an oral nutrition supplement (ONS) that provides those nutrients is typically recommended. ONS come in many forms, including liquids, puddings, bars, frozen desserts, and cookies, that are fortified with protein and/or calories.
NUTRITION 101: MICRONUTRIENTS
Vitamins and minerals are considered micronutrients. They play an astounding number of roles in the body, from co-factors in cellular reactions (zinc, among others), to energy production (B vitamins), to oxygen transport (iron). Micronutrient needs as established by the Institute of Medicine are age-based but not weight-based.4 Micronutrients include fat-soluble vitamins (vitamins A, D, E, K), water-soluble vitamins (B vitamins and vitamin C), and minerals (iron, zinc, copper, calcium, magnesium, potassium, phosphorous, chlorine, sodium, manganese, molybdenum, selenium, cobalt, chromium, fluoride, and iodine5). The vitamins and minerals that play roles typically associated with wound healing include vitamin A, vitamin C, zinc, copper, and iron. Table 1 outlines both the macro- and micronutrients that are thought to be important to wound healing.1,5-8
NUTRIENT NEEDS FOR WOUND HEALING
The most well-respected nutritional guidelines available to clinicians are found in the European Pressure Ulcer Advisory Panel (EPUAP), National Pressure Ulcer Advisory Panel (NPUAP), and Pan Pacific Pressure Injury Alliance (PPPIA). In 2014, these three organizations collaborated to publish the Prev T Pressure Ulcers: , which is based on a combination of scientific evidence and expert opinion. Table 29,10 outlines the guideline’s nutrition recommendations for protein, amino acids, calories, fluids, and vitamins and minerals to prevent and treat pressure injuries. To summarize, the guideline suggests that supplemental fluid, protein, and calories may be required (if needs cannot be met by food alone) and that highprotein, arginine, and micronutrients may be necessary for adults living with a stage III or IV pressure injury, if their needs cannot be met by traditional high-calorie and protein supplements.9,10 They also suggest that multivitamin or zinc supplements should be considered if a deficiency is confirmed or suspected.9,10 Questions remain about the benefits of ONS or vitamin/mineral supplements for chronic wound patients. According to a 2014 Cochrane Review of nutritional interventions for wound healing, there is currently no clear evidence of benefits associated with nutritional interventions for prevention or treatment of pressure injuries.11 Many clinicians have observed benefits to supplemental nutrition despite research that has been inconclusive. Some suggest that the synergistic effect of nutrients in combination may be more important than the effect of individual nutrients.12 As healthcare professionals ponder how to maximize nutritional status for chronic wound patients, research on the role of nutrients on wound healing continues.
MEETING NUTRIENT NEEDS
Based on the knowledge that we have today, the best way to meet the nutrient needs of most chronic wound patients is by educating them to consume a healthy diet that includes a variety of nutrient-dense foods. The United States Department of Agriculture offers an educational tool known as ChooseMyPlate that establishes a template for meal planning to help patients meet the goal of consuming a healthful diet.8 Outpatient wound clinic program directors and clinicians should also consider collaboration with an RDN who can evaluate a patient’s food habits, lifestyle, and nutritional needs to determine if supplemental nutrition as outlined by NPUAP, EPUAP, and PPPIA guidelines might be necessary. Monitoring of serial weights, wound healing progress, food and fluid intake, and intake of ONS or vitamin/mineral supplements is the best way to determine if nutritional needs are being met. Will a multivitamin or multivitamin with minerals hurt a patient? Probably not, but it might not be beneficial. Are supplements of individual nutrients harmful? Vitamin C supplements, if deemed necessary, have few (if any) side effects. Vitamin A should be administered in a 10-14-day course to prevent acute toxicity.7 Supplemental zinc can affect copper status, so it is suggested that zinc supplements be limited to 2-3 weeks’ duration.9,10 Rather than automatically ordering macro- and/or micronutrient supplements, clinicians should consider if a patient is receiving adequate amounts of those nutrients from their food intake, ONS, multivitamin, or enteral or parenteral nutrition.
• Weight loss is usually an indicator that protein, calorie, fat, and/or fluid needs are not being met. • Clinicians should encourage their wound care patients to consume a healthy diet based on the ChooseMyPlate guidance.8 • Supplemental calories and/or protein and/or amino acids may be necessary for some patients. • Vitamin and mineral supplements may be needed if a vitamin or mineral deficiency is confirmed or suspected.
Liz Friedrich is president of Friedrich Nutrition Consulting, a North Carolina-based company that specializes in gerontological nutrition and wound care.
1. Posthauer ME, Dorner B. Nutrition and wound care. In: Baronski S, Ayello EA, eds. Wound Care Essentials: Practice Principles. 4th ed. Philadelphia PA: Wolters Kluwer; 2016.
2. Lee SK, Posthauer ME, Dorner B Redovian V, Maloney MJ. Pressure ulcer healing with a concentrated, fortified, collagen protein hydrolysate supplement: a randomized controlled trial. Adv Skin Wound Care. 2006;19(2):92-6.
3. Ohura T, Nakajo T, Okada S, Omura K, Adachi K. Evaluation of effects of nutrition intervention on healing of pressure ulcers and nutritional states (randomized controlled trial). Wound Repair Regen. 2011;19(3):330-6.
4. Dietary reference intakes. United States Department of Agriculture. Accessed online: www.nal.usda.gov/fnic/dietary-reference-intakes
5. Duyff RL. Academy of nutrition and dietetics complete food and nutrition guide. Chicago IL: Academy of Nutrition and Dietetics; 2017.
6. Stechmiller JK. Understanding the role of nutrition in wound healing. Nutr Clin Pract. 2010; 25(1):61-8.
7. Quain AM, Khardori NM. Nutrition in wound care management: a comprehensive overview. Wounds. 2015;27(12):327-35.
8. ChooseMyPlate. United States Department of Agriculture. Accessed online: www.choosemyplate.gov
9. NPUAP, EPUAP, Pan Pacific Pressure Injury Alliance. Prevention and treatment of pressure ulcers: clinic practice guideline. 2014. Emily Haesler (Ed.). Cambridge Media: Osborne Park, Western Australia; 2014.
10. Posthauer ME, Banks M, Dorner B, Schols JM. The role of nutrition for pressure ulcer management: national pressure ulcer advisory panel, european pressure ulcer advisory panel, and pan pacific pressure injury alliance white paper. Adv Skin Wound Care. 2015;28(4):175-88.
11. Langer G, Fink A. Nutritional interventions for preventing and treating pressure ulcers. Cochrane Database Syst Rev. 2014(6).
12. Cereda E, Klersy C, Serioli M, Crespi A, D'Andrea F, Oligo Element Sore Trial Study Group. A nutritional formula enriched with arginine, zinc, and antioxidants for the healing of pressure ulcers: a randomized trial. Ann Intern Med. 2015;162(3):167-74.