Importance of Zinc To The Immune System
By Dr. W. Shaw
Zinc is an essential element that is commonly deficient in individuals who eat a diet high in cereal content but low in animal protein. Cereals contain phytic acid which binds zinc and inhibits its absorption form the intestinal tract. clinical signs of zinc deficiency may occur when plasma zinc concentrations drop below 65 mcg/dL. Zinc deficiency is associated with dermatitis, poor wound healing, retarded growth and sexual development, and reduced taste acuity. Values less than 33 mcg/dL are particularly associated with loss of the senses of taste and smell, abdominal pain, diarrhea, skin rash, and loss of appetite.
Zinc deficiency may be common in children with autism who may have had diarrhea for extended periods and may contribute to their poor appetites. Zinc affects multiple aspects of the immune system, from the barrier of the skin to gene regulation with lymphocytes. Zinc is crucial for the normal function of cells which mediate nonspecific immunity, such as neutrophils and natural killer cell. B lymphocyte development and antibody production, particularly immunoglobulin G, is compromised by zinc deficiency. The macrophage, a pivotal cell in many immunoligic functions, is adversely affected by zinc deficiency. This can dysregulate intracellular killing cytokine production and phagocytosis. The effects of zinc on these key immunoligic mediators is rooted in the myriad roles for zinc in basic cellular functions such as DNA replication, RNA transcription, cell division, and cell activitation. Apoptosis or programmed cell death is potentiated by zinc deficiency. Zinc also functions as an antioxidant and can stablize membranes.
Zinc deficiency and Crohn's disease
Low serum zinc in Crohn's disease may cause clinical manifestations, such as acrodermatitis enterophatica and retinal dysfunction, which may be correctable with zinc supplementation.
Zinc treatment of Candidiasis.
Polizzi and coworkers evaluated the clinical efficacy of a treatment with cimetidine and zinc sulfate in an adult patient with chrominc mucocutaneous candidiasis. Cimetidine was given at a dose of 400 mg three times daily; zinc sulfate at a dose of 200 mg daily, then adjusted to maintain blood zinc levels at the upper normal range. This treatment lasted 16 months. An impressive and significant reduction of the infectious events and an increased CD4 (helper/inducer) cell counts were observed. The authors conclude that this combined immunopotentiating treatment is safe and inexpensive to treat immunodeficiency disorders.
Zinc reduction of infectious diseases
The August 1998 issue of the American Journal of Clinical Nutrition is devoted to studies on zinc and health. Anuraj Shankar, an immunologist at the Johns Hopkins School of Public Health, working with other experts in a child health study, found the trace mineral can have remarkable effects. They found that adding small amounts of zinc to the diet could reduce the duration of a diarrhea attack by 20 to 30 percent and could stop up to 38 percent of cases from ever happening. "The incredible thing about zinc is that if you look at the three major killers of children everywhere - - diarrhea, malaria and pneumonia -- we are seeing that zinc has a very significant impact on reducing the severity and incidence of those." siad Shankar. Zinc supplementation reduced acute respiratory infections such as pneumonia by up to 45 percent and malaria by 35 percent, Shankar said in a telephone interview. One study in India found that the children with low blood levels of zinc had more bouts of diarrhea, and were more likely to have fever along with diarrhea. A study in Vietnam found a 2.5 -fold decrease in all respiratory infections when children received zinc supplements.
Hyperactivity, zinc deficiency and food dyes.
Children with hyperactivity had significantly lowered hair, blood, fingernail and urine zinc compared to age and sex-matched controls. The yellow food dye tartrazine may bind to zinc in the blood as a chelating agent and thereby reduce blood zinc. Hyperactive children exposed to this food dye all developed significant negative symptoms within 45 minutes of ingesting this food dye in a colored drink.
Zinc deficiency and anorexia nervosa.
A number of studies have indicated that a high percentage of females with anorexia nervosa may have low serum zinc values, may choose diets with inadequate zinc content, and may respond favorably to zinc supplementation by increased weight gain and reduced depression and anxiety.
Reproduced with permission of Dr W. Shaw at Great Plains Laboratory.