Plasma lipids and fatty acids in urbanized Bushmen, Hereros and Kavangos of southern Africa (Namibia).

Thirty-nine urbanized ethnic Namibian people comprising 21 Bushmen (semi-urbanized), 7 Hereros and 11 Kavangos were assessed for plasma lipids and fatty acid (FA) composition. Total cholesterol and triacylglycerol concentrations were measured by enzymatic methods, and neutral lipid FA composition by gas-liquid chromatography. The results demonstrated that while total cholesterol concentrations were not significantly different, significant differences in triacylglycerol concentrations (P < 0.05) were seen between Bushmen and Kavangos. By comparing Bushmen with Hereros and Kavangos, significant differences between Bushmen and Kavangos were also observed in plasma triacylglycerol FA compositions, particularly 16:0 (32.73% vs. 25.05%), 16:1n-7 (7.00% vs. 5.06%), 18:2n-6 (9.30% vs. 22.25%) and 20:3n-6 (0.12% vs. 0.48%), while Kavangos had higher 20:4n-6 levels than Hereros (1.44% vs. 2.00%). In plasma cholesteryl esters, Bushmen were significantly different from Kavangos in 16:1n-7 (8.85% vs. 4.93%), 18:1n-9 (32.06% vs. 23.07%) and 20:4n-6 (6.91% vs. 10.00%). Significant differences were also observed between Bushmen and Hereros in 18:0 (1.08% vs. 1.29%) and 18:2n-6 (35.68% vs. 45.50%). The FA of Namibian groups were also compared with South African reference groups comprising urbanized whites and Xhosas and rural Vendas. The differences in blood lipid values can be explained primarily by excessive alcohol consumption. These results suggest that semi-urbanized Bushmen have changed their diets under urbanized conditions which may increase their risk of coronary heart disease.