The fluidity of the serum phospholipids of Fulani pastoralists consuming a high-fat diet.

Abstract

The semi-nomadic cattle Fulani of northern Nigeria consume a diet rich in saturated fatty acids. Since the quality of an individual's dietary fat can influence the fatty acid composition of their membrane phospholipids (PL), we investigated the effect consumption of relatively large amounts of saturated fat might have on the fatty acid composition and fluidity of the serum PL of the Fulani. We obtained blood serum from 112 Fulani pastoralists (38 males, 74 females) 15-77 years of age and determined the serum fatty acid composition of the total PL fraction of each specimen. Our results indicate that the PL of the Fulani were enriched for saturated fatty acids. The unsaturated/saturated fatty acid ratio was 1.02 for the Fulani PL compared to 1.22-2.08 for seven other reference groups drawn from published reports. In addition, the mean melting point (MMP) of the fatty acyl chains of the serum PL of the Fulani was considerably higher than that of the reference populations (MMP, 30.6 degrees C versus 21.3-26.1 degrees C, respectively). The double bond index (DBI) of the serum PL of the Fulani was much lower than that of the PL of the groups against which comparisons were made (DBI, 0.98 versus 1.24-1.43, respectively). Since serum PL and tissue PL are in dynamic equilibrium, these findings suggest that the tissue PL of the Fulani we studied has considerably less fluid character than those of other populations. Since a variety of membrane functions depend on the fluid property of the acyl chains of their constituent PL, it is conceivable that certain critical membrane-dependent systems, including receptor-ligand interactions, solute transport, enzyme activity and lateral movement of macromolecules, are affected in the Fulani.