Essential amino acid supplementation for pressure ulcers: pathophysiological rationale and results from a pilot study

Pressure ulcers (PU) are a major and serious problem affecting millions of people. Malnutrition, frequently co-occurring with PU, is considered modifiable risk factor, and dietary supplements currently recommended for supporting PU healing contain a high amount of protein and some additives (zinc, vitamin C, arginine). Unfortunately, many patients with PU suffer from chronic kidney disease and would not tolerate a high-protein diet. Amino acid profiling of the blood serum of PU patients has shown decreased concentrations of exogenous amino acids histidine, tryptophan and threonine. Their common feature is a low daily requirement, 4 to 15 mg/kg body weight. In animal experiments, various types of stress increase metabolic demand for these amino acids. On the other hand, stress significantly slows down wound healing, both in animals and in humans. Considering these observations, a pilot clinical trial in the quasi-experimental design has been performed to assess the effect of Pellicar-F, a proprietary food composition containing histidine in the form of carnosine, plus tryptophan and threonine on PU control. After six weeks patients receiving daily doses of the aforementioned food composition, compared to control patients, displayed statistically significant reduction of the pressure ulcer area. Further evaluation of this product in pressure ulcers and other chronic wounds is indicated.