Article Abstract:
The relationship between nutrition and the immune system was recognized a long time ago when periods of famine and starvation were associated with reduced ability to fight infection. Epidemiological studies, performed in more recent years, have confirmed and extended these findings. It is now becoming evident that deficiencies of specific nutrients in the diet can impair the function of the immune system. Protein-energy malnutrition (PEM) has been shown to reduce the size and the weight, and thus the function, of the thymus, a small organ located in the chest. Since the thymus makes cells (lymphocytes) that produce antibodies and kill invading microorganisms, shrinkage of the thymus reduces the body's ability to fight infection. Also, deficiencies of vitamin A, vitamin B-6 and zinc have been shown to reduce the size of the thymus and to reduce the production of antibodies for fighting infection. Vitamins C and E are necessary for normal immune cell function, but deficiencies of these vitamins are less likely to reduce antibody production. Iron deficiency is the most common nutritional deficiency, and iron is essential for maintaining proper immune cell function. Dietary deficiencies of certain amino acids (the building blocks of proteins) have been associated with reduced immune function, and two studies have reported that glutamine and arginine may stimulate the immune system and help to prevent infection. More recently, it has been reported that the function of the immune system may decline with aging. However, this decline in immune function may be partially attributed to nutrient deficiencies (iron, vitamin C, zinc) that are common in elderly people. Correcting these deficiencies with dietary supplements has been shown to improve immune function in the elderly. Obesity has been reported to be associated with an increased risk of infection, and excessive intake of fat (lipid) has been shown to decrease the ability to fight infection. Also, consuming large amounts of zinc, selenium, vitamin A, and vitamin E may reduce immune function. All of these studies serve to illustrate the need to consume an adequate diet in order to maintain the body's ability to fight infection. (Consumer Summary produced by Reliance Medical Information, Inc.)
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Article Abstract:
Epidemiology is more and more recognized as being among of the fundamental sciences of medicine. Comparing rates of occurrence of disease in different populations may be the most fundamental contribution it makes. In the first part of the 20th century when micronutrient deficiencies were first considered, beriberi presented a problem that was almost solved by Wl Leonard Braddon, a physician of the British Colonial Service practicing in the Federated Malay States and concentrating on beriberi. His failure to find a solution involves a story that is instructive relative to separating variables in analysis.
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Article Abstract:
Elmer Verner McCollum's well-founded suggestions of newer knowledge of nutrition helped Herbert Hoover's US Food Administration deal effectively with the extensive shortages in customary foods during World War I. It was emphasized that adequate food from US would be helpful in winning the war. During World War I, McCollum delivered lectures under the leadership of Hoover, on the importance of daily diet planning and using available foods. Hoover was appreciated for showing his concern for the starving people in Europe.
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