Research: ALSALEH and COLLEAGUES,

Listed in Issue 227

Abstract

ALSALEH and COLLEAGUES, (1)Diabetes and Nutritional Sciences Division, School of Medicine, King's College London, London, UK studied the effects of fish oil supplementations upon blood pressure genetic polymorphisms, in parallel with a double-blind trial of participants receiving increasing doses of N-3 fatty acids.

Background

Blood pressure is a heritable determinant of cardiovascular disease (CVD) risk. Recent genome-wide association studies have identified several single-nucleotide polymorphisms (SNPs) associated with blood pressure, including rs1378942 in the c-Src tyrosine kinase (CSK) gene. Fish oil supplementation provides inconsistent protection from CVD, which may reflect genetic variation.

Methodology

The authors investigated the effect of rs1378942 genotype interaction with fish oil dosage on blood pressure measurements in the MARINA (Modulation of Atherosclerosis Risk by Increasing doses of N-3 fatty Acids) study, a parallel, double-blind, controlled trial in 367 participants randomly assigned to receive treatment with 0.45, 0.9, and 1.8 g/d eicosapentaenoic acid [EPA (20:5n-3)] and docosahexaenoic acid [DHA (22:6n-3)] (1.51:1) or an olive oil placebo for 12 mo. A total of 310 participants were genotyped.

Results

There were no significant associations with blood pressure measures at baseline; however, the interaction between genotype and treatment was a significant determinant of systolic blood pressure (SBP) (P = 0.010), diastolic blood pressure (DBP) (P = 0.037), and mean arterial blood pressure (MABP) (P = 0.014). After the 1.8 g/d dose, non-carriers of the rs1378942 variant allele showed significantly lower SBP (P = 0.010), DBP (P = 0.016), and MABP (P = 0.032) at follow-up, adjusted for baseline values, than did carriers. The authors found no evidence of SNP genotype association with endothelial function (brachial artery diameter and flow-mediated dilatation), arterial stiffness (carotid-femoral pulse wave velocity and digital volume pulse), and resting heart rate.

Conclusion

A high intake of EPA and DHA could help protect non-carriers but not carriers of the risk allele. Dietary recommendations to reduce blood pressure in the general population may not necessarily benefit those most at risk. This trial was registered at controlled-trials.com as ISRCTN66664610.

References

AlSaleh A(1), Maniou Z, Lewis FJ, Hall WL, Sanders TA, O'Dell SD; MARINA Study Team. Interaction between a CSK gene variant and fish oil intake influences blood pressure in healthy adults. J Nutr. 144(3):267-72. Mar 2014. doi: 10.3945/jn.113.185108. Epub Jan 8 2014. 

Munro Hall Clinic 2017

IJCA-EORC-Botanica-2016b

Scientific and Medical Network 2

The Big Heart Bike Ride Costa Rica 2018

Snowdonia Charity Challenge 2018

top of the page