Occurrence and Biological Properties of Sphingolipids - A Review

Sphingolipids are a complex group of polar lipids. Variations in their components (backbone, polar head group and fatty acid) engenders a large and complex structural variety which affects the biological properties of the individual molecules. Sphingolipids are omnipresent in foodstuffs, can cross the intestinal barrier and are biologically active. The quantities in food range from a few μg/kg in fruits and some vegetables up to 1 g/kg in milk products, eggs, meat and soybeans. Several positive impacts of sphingolipids on human health have been described: In vitro experiments measuring the antibacterial properties of sphingolipids have been successfully carried out. A sphingolipid-enriched diet showed inhibitory effects on the formation of early colon carcinoma precursors (Aberrant Crypt Foci (ACF)) in mice. Sphingolipid metabolites also induce apoptosis in transformed human cell cultures. Taken together, there is a high probability that sphingolipids have anticancerogenic properties in humans. Finally, a specific group of sphingolipids is essential for the maintenance of nerve function and structure and the enrichment of sphingomyelin in a cholesterol-rich diet successfully reduces cholesterol absorption. Although sphingolipids are probably not essential dietary components, they can significantly contribute to human health.