Gene variation modulates effect of PUFAs on plasma LDL cholesterol concentrations
MedWire News: Dietary polyunsaturated fatty acids (PUFAs) increase total and low-density lipoprotein (LDL) cholesterol concentrations in carriers of an ABCG1 gene single nucleotide polymorphism (SNP), researchers report.
The team found that carriers of the AA genotype of the rs4148102 SNP in ABCG1 who consumed a high PUFA diet showed higher plasma LDL cholesterol concentrations than did G allele carriers.
Using data from participants of two population-based studies: the Hortega study (n=1178) and the Pizarra study (n=763), Rosario Abellán (Valencia University, Spain) and colleagues investigated whether interactions between PUFA intake and ABCG1 polymorphisms modulated associations with plasma total, LDL, and high-density lipoprotein (HDL) cholesterol.
All participants were genotyped for ABCG1 variants and dietary intakes were estimated with a validated food frequency questionnaire.
In the Hortega population, A allele homozygotes of rs4148102 who consumed large amounts of PUFAs (≥13.6 g/day) had significantly higher total and LDL cholesterol concentrations than the G allele carriers, at 242.1 versus 198.0 mg/dl (6.27 vs 5.13 mmol/l) and 149.8 versus 111.4 mg/dl (3.88 vs 2.89 mmol/l), respectively.
Significant gene-PUFA diet interactions were observed for this SNP with total and LDL cholesterol, notes the team.
Similar results were observed in the Pizarra population, say Abellán and co-authors. Indeed, A allele homozygotes of the rs4148102 SNP who consumed diets with large amounts of PUFAs (≥10.6 g/day) had significantly higher total and LDL cholesterol concentrations than G allele carriers (55.5 and 51.4 mg/dl [1.44 and 1.33 mmol/l] higher, respectively). The gene-PUFA diet interactions for this population were not significant, however.
Pooled analysis revealed that with high PUFA diets, AA participants had significantly higher total and LDL concentrations than did the G allele carriers (246.8 vs 198.0 mg/dl [6.39 vs 5.13 mmol/l] and 159.0 vs 114.3 mg/dl [4.12 vs 2.96 mmol/l]). Moreover, significant gene-PUFA diet interactions were observed.
Writing in the journal Atherosclerosis, the authors say: "The present study provides the first evidence that ABCG1 gene variation modulates the effect of dietary polyunsaturated fatty acids on plasma LDL cholesterol concentrations."
They conclude that "additional functional studies to corroborate how ABCG1 polymorphisms affect sterol flux under different lipid contents in diet would provide critical information about the ABCG1 gene role in cholesterol transport, or in disease such as atherosclerosis."
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By Nikki Withers