Intakes of omega-3 polyunsaturated fatty acids and blood pressure change over time: Possible interaction with genes involved in 20-HETE and EETs metabolism

Background: A high intake of omega-3 polyunsaturated fatty acids (omega-3 PUFAs), has been associated with reduced levels of blood pressure (BP). Their antihypertensive action may be due to the reduction of the omega-6/omega-3 ratio and the resulting competitive effect of omega-3 as compared to arachidonic acid (an omega-6 PUFA) as a substrate of cytochrome P450 (CYP450) enzymes involved in the production of vasoactive mediators. Some functional polymorphisms (SNPs), in genes which encode for the same enzymes, were associated with hypertension and ischemic stroke in the Malmo Diet and Cancer (MDC), a Swedish urban-based longitudinal study. The aim of this study was to evaluate the effect of the intake of different types of PUFAs on BP change over time (Delta-BP; mean follow-up 16.6 +/- 1.5 years; n =3.550 with complete phenotypic data), also considering the interaction with SNPs in genes involved in their metabolism via CYP450. Methods: PUFA intakes were collected by a modified diet history method, and functional SNPs in CYP4F2, CYP4A11, CYP2J2 and EPHX2 were genotyped by Taqman. Result: We did not find any overall association between omega-6 and omega-3 PUFA intakes, or their ratio, with Delta-BP but observed an interaction between CYP4F2 V433M genotype and total omega-3, alpha-linolenic acid and linoleic/alpha-linolenic ratio, so that a higher omega-3 PUFA intake was significantly associated with a more pronounced BP decrease over time in subjects with the 433VV genotype (-0.041 +/- 0.018 mmHg/year; p = 0.024; p-interaction = 0.031). Conclusions: Our data do not support a major role of omega-6 or omega-3 PUFA intakes on BP change over time, but suggest a possible interaction of omega-3 PUFA with the CYP4F2 V433 M. (C) 2015 Elsevier Inc. All rights reserved.