Confounding Factors in the Nutrition Infection Relationship

Infection and malnutrition are interdependent indices; however, the nature of the interaction between nutrition and immunity is complex and is confounded by factors that affect both nutritional status and immunocompetence (Figure 3).

Despite the clinical evidence for increased frequency and severity of infections in malnourished individuals, the major factor confounding the relationship between nutrition and immune status is that the environmental conditions of poverty simultaneously lead to both malnutrition and increased exposure to infections. The increase in morbidity and mortality from infectious diseases in malnourished children is often attributed to mucosal and epithelial damage caused by malnutrition, whereas this damage may be caused by the infection itself, making it difficult to confirm a causal path in the malnutrition-infection paradigm.

Furthermore, studies investigating the effects of single nutrient deficiency on infection are often confounded by coexisting nutritional deficiencies, and although nutrition can modulate immunocom-petence, susceptibility to secondary opportunistic infection can be independent of nutritional status.

Additionally, the assessment of nutritional status is complicated by the presence of infection, as is the diagnosis of infection in malnourished individuals. During the acute phase response to infection, the plasma concentrations of many micronutrients are altered making it difficult to assess nutritional status, whereas the metabolic and physiological changes (reductive adaptation) that occur in severe malnutrition impair immune responses, making it difficult to diagnose infection.

Food Allergies

Food Allergies

Peanuts can leave you breathless. Cat dander can lead to itchy eyes, a stuffy nose, coughing and sneezing. And most of us have suffered through those seasonal allergies with horrible pollen counts. Learn more...

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