Effect of diet on lung structure, connective tissue metabolism and gene expression.

Nutritional impairment can adversely affect the respiratory system. The structure of the lung is altered by severe calorie-protein restriction in rodents producing an emphysema-like lesion after several weeks of severe caloric restriction. Biochemical and morphological evidence suggests destruction of collagen and elastin in nutritional emphysema. Impaired lung growth may explain the biochemical changes in growing animals. Although the molecular basis of nutritional emphysema is not known, altered gene expression by nutrients affects several metabolic pathways, and examples of the effects of nutrients on gene expression are given. Nutritional emphysema in animals may be relevant to humans because malnutrition may accelerate the progression of the disease in patients with advanced emphysema.