Short-Term Dietary Intake of C18:1 Trans Fatty Acids Decreases the Function of Cellular Immunity in Healthy Young Men

Aim: In this study, we tested the impact of short-term intake of increased amounts of C18:1 trans fatty acids (TFAs) on parameters of cellular and humoral immunity in healthy young men. Methods: Twenty-seven healthy young men were subsequently exposed to a standard diet for 7 days and an experimental TFA-enriched diet for 4 days. The mean energy content of these diets was 2,453 and 2,455 kcal/day, with 10, 35 and 55% of energy from proteins, fats and carbohydrates, respectively. Standard diet contained about 0.8 g and experimental diet 10.4 g TFAs. Plasma levels of C18: 1 TFAs and immunological parameters were measured. Results: The 4-day increased consumption of C18: 1 TFAs led to a significant decrease in mitogen-induced CD69 expression on CD8+ T cells as well as decreased phagocytic activity on neutrophils. After returning to the participants' habitual diet (1 week after the end of the experimental diet), we observed a significant decrease in the mean level of circulating immune complexes. Concentrations of plasma immunoglobulins remained unchanged throughout the study. Conclusions: Acute impact of higher dietary C18: 1 TFA intake on phagocytosis and cell-mediated immunity seems to be suppressive. This finding differs from results describing proinflammatory effects associated with long-term exposure to TFAs. Copyright (C) 2008 S. Karger AG, Basel