Role of alcohol abuse in nutritional immunosuppression.

Nutritional status is an important determinant of the host resistance against infections and tumors. Alcohol interferes in various ways with the complex system of nutritional immunomodulation. Alcohol acts directly on mechanical barriers in the gastrointestinal tract and increases permeability of intestinal walls, which results in a reduced exclusion of immunogenic material in the intestine. Alcohol further affects granulocytopoiesis and suppresses various immune functions. Indirect effects on the immune response are caused by alcohol-induced malnutrition. Heavy alcohol abuse is associated with a high energy intake derived by alcohol and an inadequate intake of protein, vitamins and minerals. In addition, alcohol abuse impairs absorption, utilization, storage and excretion of nutrients, which together with inadequate nutrient intakes results in nutritional immunosuppression. The high incidence of infections in alcoholics could be one consequence of the alcohol-induced immunosuppression.