Can Purified Omega-3 Polyunsaturated Fatty Acids Supplementation Act Blood Pressure Levels in Untreated Normal-High Blood Pressure Subjects with Hypertriglyceridemia?

Maria Leonarda De Rosa

doi:10.4236/pp.2012.32031

Abstract

Omega-3 (ω-3) polyunsaturated fatty acids (PUFAs) from fish and fish oils appear to protect against coronary heart disease: their dietary intake is in fact inversely associated with cardiovascular disease morbidity/mortality in population studies. Recent evidence suggests that at least a part of this protective effect is mediated by a relatively small but significant decrease in blood pressure (BP) level. In fact, omega-3 PUFAs exhibit wide-ranging biological actions that include regulating both vasomotor tone and renal sodium excretion, partly competing with omega-6 PUFAs for common metabolic enzymes and thereby decreasing the production of vasoconstrictor rather than vasodilator and anti-inflammatory eicosanoids. PUFAs also reduce angiotensin-converting enzyme (ACE) activity, angiotensin II formation. We retrospectively evaluated the long-term effect of a omega-3 PUFAs supplementation on the blood pressure level of 91 hypertriglyceridemic subjects with untreated normal-high blood pressure that were prescribed a 3 grams omega-3 PUFAs supplementation in order to improve their plasma lipid pattern. After 24 months of treatment, systolic blood pressure (SBP) meanly decreased by 2.6 +/- 2.5 mmHg (p = 0.001) and diastolic blood pressure (DBP) by 1.4 +/- 3.1 mmHg (p < 0.001), while basal heart rate decreased by 4.1 +/- 4.6 bpm (p < 0.001). Both SBP and DBP reduction were significantly related to the baseline SBP (p < 0.001) and DBP (p < 0.001), respectively. Diastolic blood pressure change was also inversely related to the patient’s age (p = 0.004). No significant difference was perceived in the metabolic syndrome subgroup. In our retrospective study, highly purified omega-3 PUFAs long-term supplementation is associated with a significant reduction in SBP, DBP, and basal heart rate in hypertriglyceridemic patients with normal-high blood pressure. The main determinants of the omega-3 PUFAs anti-hypertensive effect appear to be the basal blood pressure level and age. Future research will clarify if omega-3 PUFAs supplementation could improve the antihypertensive action of specific blood pressure lowering drug classes and of statins.

Highlights

Dietary factors play a major role in the pathogenesis of essential hypertension
Omega-3 (ω-3) polyunsaturated fatty acids (PUFAs) from fish and fish oils appear to protect against coronary heart disease: their dietary intake is inversely associated with cardiovascular disease morbidity/mortality in population studies
Several lines of evidence suggest that supplementation of diet with omega-3 polyunsaturated fatty acids ( ω-3 PUFAs), commonly referred to as fish oil, may reduce blood pressure; it is likely that animals fed 10% safflower oil with 30% casein had higher amounts of free radicals and pro inflammatory cytokines and developed hypertension as a consequence of low-grade systemic inflammation [1,2]

Summary

Introduction

Several lines of evidence suggest that supplementation of diet with omega-3 polyunsaturated fatty acids ( ω-3 PUFAs), commonly referred to as fish oil, may reduce blood pressure; it is likely that animals fed 10% safflower oil with 30% casein had higher amounts of free radicals and pro inflammatory cytokines and developed hypertension as a consequence of low-grade systemic inflammation [1,2] These evidences are relevant to patients with chronic renal failure; high-protein diet enhances oxidative stress and interferes with the production of lipoxins, resolvins, protectins, and maresins (anti-inflammatory compounds) that could adversely affect the underlying renal disease [3]. Arachidonic acid, EPA and docosahexaenoic acid (DHA) (formed from eicosapentenoic acid) form precursors to the anti-inflamma-

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