title: Fish intake, independent of apo(a) size, accounts for lower plasma lipoprotein(a) levels in Bantu fishermen of Tanzania: The Lugalawa Study.
abstract: Plasma lipoprotein(a) [Lp(a)] levels are largely genetically determined by sequences linked to the gene encoding apolipoprotein(a) [apo(a)], the distinct protein component of Lp(a). Apo(a) is highly polymorphic in length due to variation in the numbers of a sequence encoding the apo(a) kringle 4 domain, and plasma levels of Lp(a) are inversely correlated with apo(a) size. In 2 racially homogeneous Bantu populations from Tanzania differing in their dietary habits, we found that median plasma levels of Lp(a) were 48% lower in those living on a fish diet than in those living on a vegetarian diet. Considering the relationship between apo(a) size and Lp(a) plasma concentration, we have extensively evaluated apo(a) isoform distribution in the 2 populations to determine the impact of apo(a) size in the determination of Lp(a) values. The majority of individuals (82% of the fishermen and 80% of the vegetarians) had 2 expressed apo(a) alleles. Additionally, the fishermen had a high frequency of large apo(a) isoforms, whereas a higher frequency of small isoforms was found in the vegetarians. When subjects from the 2 groups were matched for apo(a) phenotype, the median Lp(a) value was 40% lower in Bantus on the fish diet than in those on the vegetarian diet. A significant inverse relationship was also found between plasma n-3 polyunsaturated fatty acids and Lp(a) levels (r=-0.24, P=0.01). The results of this study are consistent with the concept that a diet rich in n-3 polyunsaturated fatty acids, and not genetic differences, is responsible for the lower plasma levels of Lp(a) in the fish-eating Bantus and strongly suggest that a sustained fish-based diet is able to lower plasma levels of Lp(a).
mesh_terms: D000328:Adult; D000818:Animals; D001054:Apolipoproteins A / Q000097:blood*; D001095:Arachidonic Acids / Q000097:blood; D044383:Black People / Q000235:genetics; D002784:Cholesterol / Q000097:blood; D014676:Diet, Vegetarian; D005006:Ethnicity / Q000235:genetics; D015525:Fatty Acids, Omega-3 / Q000097:blood*; D005247:Feeding Behavior; D005260:Female; D005399:Fishes; D006801:Humans; D017270:Lipoprotein(a) / Q000097:blood*; D008297:Male; D008460:Meat; D009790:Occupations; D010641:Phenotype; D020033:Protein Isoforms / Q000097:blood*; D013636:Tanzania / Q000453:epidemiology; D014280:Triglycerides / Q000097:blood