Nutritional issues in the care of the elderly patient.

Aging is associated with a progressive decline in the function of many organs and apparatus. In a medical context, depletion of lean body mass and muscle mass in particular, and alteration of the immune system are of utmost importance. A defective immune response is associated with an increased incidence of inflammatory, infective and neoplastic diseases in the elderly as well as with a slow and sluggish recovery after illness or other injury. Depletion of muscle mass, the so-called sarcopenia, is responsible for the typical frailty of the elderly. Moreover, since muscle represents the protein reserve of the body, its progressive erosion not only results in a poor mobility and disability of these subjects, with associated complications, but with a diminished capacity to meet the extra demand of protein synthesis associated with disease and injury. In cancer patients, as in other elderly patients with different pathologies, it is important to evaluate the nutritional status, since frailty of these individuals recognizes as a relevant etiopathogenetic cofactor, a defective food intake. Nutritional support should aim at meeting the requirements in macronutrients, in water and in micronutrients. Requirements are not so different from those of adult subjects, since the decrease in energy expenditure due to a lower physical activity is compensated by the increase due to the disease. Particular attention must be given to fluid administration, since the elderly tolerate fluid overload less than hypohydration. Elderly patients quite frequently suffer from long-standing undernutrition; this means that nutritional repletion will take more time than is usually expected with use of medication. If a correct feeding program is performed for a few weeks, a benefit can be observed not only on the nutritional status but also in the clinical outcome. In fact nutritional support may have a permissive role in the administration of aggressive (oncologic) treatment than may be otherwise denied to elderly patients.