Symptoms Of Infections In Your Immune System

The immune system protects the body against infection by producing specific substances in response to foreign materials called antigens. Immunity to specific antigens occurs through the cooperative interactions of two subsets of blood cells, T lymphocytes and B lymphocytes.

There are several subtypes of T lymphocytes, each with specific functions. Helper and suppressor T lymphocytes regulate the quantities of antibodies produced, while killer T lymphocytes respond selectively to foreign material, search and destroy internally infected, or malignant body cells.

Severe infections can compromise nutritional status through a variety of mechanisms: hypermetabolism, appetite depression, decreased absorption of nutrients, altered nutrient metabolism, increased nutrient excretion, and internal diversion of nutrients. additional nutrient losses occur with vomiting, diarrhea, and sweating.

Hypermetabolism

Fever causes metabolic rates to increase. This hypermetabolism affects all cells in the body. Because this extra energy comes largely from amino acid metabolism the body stores of muscle protein amino acids are rapidly depleted. Loss of nutrients also occur during sweating associated with fever. Controlling the infection reduces fever and losses of body nutrients.

Severe loss of appetite is a common symptom during most infectious diseases and often leads to an almost total cessation of food consumption. Vomiting and diarrhea further reduce the absorption of nutrients. Antibiotics and other medications also modify intestinal absorption.

Excess nitrogen is metabolized to urea and excreted in the urine. Even brief viral infections and brief fevers induced by bacterial infections can cause sizable losses of nitrogen.

Tissue and plasma concentrations of most vitamins decline during infections, because of increased metabolism or excretion. The accelerated metabolism or loss of vitamins during infections may precipitate recognizable deficiency states.

Food Associated Illnesses

Adverse reactions to food involve immunologic and nonimmunologic mechanisms. Immunologic reactions are known as food allergies. Nonimmunologic intolerances include those that are biochemical or psychologic.

Food allergies are examples of the negative consequences of immune function on the gastrointestinal tract, skin, lungs, and other organs. The most common foods to which people are allergic are eggs, milk, fish, shellfish, chicken, wheat, and nuts. Symptoms include acute abdominal pain, swelling, nausea,vomiting, rashes, chronic itching, headache, tension, and fatigue.

The causes of nonimmunologic adverse reactions to foods include food toxicities, food poisonings, and pharmacologic or metabolic reactions. Such intolerances occur more frequently than true food allergies and are related to dose as well as to the concurrent presence of medications, other diseases, or genetic errors of metabolism.

Sulfites

Approximately 10 percent of people with asthma are sensitive to ingestion of sulphite, which induces asthma. Foods containing sulfur dioxide, as a preservative, should be used with caution.

FDA has taken two major steps to protect consumers who are sensitive to sulfites in food. No longer can these preservatives be used on raw fruits and vegetables. And processed foods that contain sulfites will have to say so on the package label.

The allergic-type reactions range from mild to severe, and in some cases can cause death. "Sulfites" or "sulfating agents" are general terms used to describe sulfur based substances that have been in widespread use for many years by the food and drug industries. They include sulfur dioxide, sodium sulfite, sodium and potassium bisulfite, and sodium and potassium metabisulfite. Although they have various permitted uses, their primary function is as a preservative or antioxidant to prevent or reduce spoilage and discolouration during the preparation, storage and distribution of many foods.

There is some evidence that some non-asthmatics also can suffer adverse reactions to sulfites. For example, out of more than 500 reports of sulfite reactions investigated by the FDA, about one-fourth involved people who had no known history of asthma.

Asthma is also induced by tartrazine, a yellow dye used to color medicines, soft drinks, and foods. Tartrazine can also cause hyperactivity in sensitive individuals. It has no nutritional value. Because of the negative effects associated with tartrazine, foods and drinks containing it should be avoided. Other substances that cause adverse reaction or neurologic disorders are monosodium glutamate (MSG) and the preservative benzoic acid.

Psychologic mechanisms can provoke physical and mental symptoms of food sensitivity that do not appear to be medicated by the immune system. In individuals with psychologically induced allergic symptoms no physiologic or biochemical nonimmunologic mechanisms can be identified.

Individuals with food intolerances should exclude the offending foods from their diet. Those with potentially life-threatening sensitivities should carry an epinephrine-containing syringe and wear a bracelet identifying the problem.

HIV Infection and AIDS

Acquired immunodeficiency syndrome (AIDS), caused by the human immunodeficiency virus (HIV), is a disease with multiple pathologies, most of which are the consequence of a profound immunodeficiency.

Weight loss and deteriorating nutritional status are critical features of the AIDS disease. Anorexia, nausea and vomiting, fever, and diarrhea are common features of advanced AIDS, as are malabsorption of fats, carbohydrates, and protein. Immune abnormalities resulting from malnutrition seen in AIDS implies that malnutrition might predispose to AIDS or that nutritional therapy might improve immune status and prevent AIDS.

Folate levels were measured in HIV-infected patients. For persons not supplemented with folic or folinic acid and not taking antifolate drugs, serum and erythrocyte folate was decreased significantly. Folate deficiency was frequent and observed at all stages of HIV infection. [Boudes, P. et al: The Lancet. 335:1401, 1990.]

Nutrition Programs and Services

Food Labels:
Evidence related to diet-immune function interactions reinforces the need for food manufacturers to include explicit and complete ingredient statements to protect individuals who may have severe adverse reactions to foods.

Food Services:
Current evidence about the role of dietary factors in the maintenance of optimal immune function currently has no special implications for change in policy related to food service programs. Evidence related to the spread of infections suggests that food service personnel should receive adequate training in sanitary food handling and storage procedures.

Food Products:
Evidence related to diet-immune function interactions suggests that food product manufacturers should take special precautions to use good manufacturing practices to avoid contamination with ingredients that may produce severe reactions and to reduce microbial and chemical contamination during production and storage. Manufacturers should continue to develop new products that are free of substances likely to induce allergic symptoms in susceptible individuals. [The Surgeon General's Report on Nutrition & Health, 1988.]

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