Nutrition and Disease
The link between proper nutrition and healthy living has long been established. As medicine shifts away from exclusively managing the symptoms of disease with common pharmaceuticals, the attention of physicians worldwide is shifting to examine the unique nutritional requirements originating in various disease states to improve the body’s response to disease and improve overall clinical outcomes. Most, if not all, illnesses are now thought to be associated with an underlying nutritional requirement, and managing this increased nutritional need associated with disease is recognized as a crucial therapeutic step.
Increased nutritional requirements can be the result of inadequate ingestion of nutrients, malabsorption, impaired metabolism, loss of nutrients due to diarrhea, or increased nutritional turnover rates inherent in certain diseases (such as cancer or infectious diseases). Nutritional deficiency induced by increased requirement progresses in stages; each stage developing over a considerable period of time. The first stage is a change in nutrient levels in blood and tissues, followed by intracellular changes in biochemical functions and structures, and finally, symptoms and signs appear at the level of the entire organism (1). While nutritional deficiencies can occur in all segments of the population, they are more frequently observed in elderly and hospitalized patients with chronic diseases. Increased nutritional requirements occur, however, in a large number of disease states.
Nutritional requirements and Nutritional Deficiencies in Disease States "[T]he distinctive nutritional needs associated with a disease reflect the total amount needed by a healthy person to support life or maintain homeostasis, adjusted for the distinctive changes in the nutritional needs of the patient as a result of the effects of the disease process on absorption, metabolism and excretion." -Dr. Robert Moore, Center for Food Safety and Applied Nutrition, FDA
Clinical studies have demonstrated the relationship between specific disease states and nutritional needs (2). Chronic diseases like diabetes and gastro-intestinal (GI) tract disorders, and surgical procedures such as intestinal resection lead to impaired absorption of fat-soluble vitamins, vitamin B12, Ca, and iron, potentially causing nutritional deficiencies. Gluten enteropathy, pancreatic insufficiency, or other disorders can also result in malabsorption. Decreased absorption of iron can contribute to iron deficiency and osteoporosis. Liver disorders impair storage of vitamins A and B12 and interfere with protein and energy metabolism. Renal insufficiency predisposes patients to protein, iron, and vitamin D deficiencies, while infections, trauma, hyperthyroidism, extensive burns, and prolonged fever lead to increased metabolic demands. Any condition that increases cytokines may be accompanied by muscle loss, lipolysis, low albumin levels, and anorexia, altering the body’s nutritional requirements (3).
- http://www.merck.com/mmpe/sec01/ch002/ch002a.html
- Some of the literature is reviewed in Morgan and Baggott, 2006, Medical Foods: Products for the Management of Chronic Diseases, Nutrition Reviews, 64 (11) and Thomas et. al, 2000, Nutritional Management in Long-Term Care, Development of a Clinical Guideline, The Journals of Gerontology Series A: Biological Sciences and Medical Sciences 55:M725-M734
- Nutrition Deficiencies, The Merck Manuals Online Medical Library available at http://www.merck.com/mmpe/sec01/ch002/ch002a.html accessed March 27, 2008