Rise in DPA Following SDA-Rich Dietary Echium Oil Less Effective in Affording Anti-Arrhythmic Actions Compared to High DHA Levels Achieved with Fish Oil in Sprague-Dawley Rats.

Mahinda Abeywardena,Michael Adams,Julie Dallimore,Soressa Kitessa

doi:10.3390/nu8010014

Mahinda Abeywardena, Michael Adams + Show 2 more

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https://doi.org/10.3390/nu8010014

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Abstract

Stearidonic acid (SDA; C18:4n-3) has been suggested as an alternative to fish oil (FO) for delivering health benefits of C ≥ 20 long-chain n-3 polyunsaturated fatty acids (LC n-3 PUFA). Echium oil (EO) represents a non-genetically-modified source of SDA available commercially. This study compared EO and FO in relation to alterations in plasma and tissue fatty acids, and for their ability to afford protection against ischemia-induced cardiac arrhythmia and ventricular fibrillation (VF). Rats were fed (12 weeks) diets supplemented with either EO or FO at three dose levels (1, 3 and 5% w/w; n = 18 per group). EO failed to influence C22:6n-3 (DHA) but increased C22:5n-3 (DPA) in tissues dose-dependently, especially in heart tissue. Conversely, DHA in hearts of FO rats showed dose-related elevation; 14.8%–24.1% of total fatty acids. Kidney showed resistance for incorporation of LC n-3 PUFA. Overall, FO provided greater cardioprotection than EO. At the highest dose level, FO rats displayed lower (p < 0.05) episodes of VF% (29% vs. 73%) and duration (22.7 ± 12.0 vs. 75.8 ± 17.1 s) than the EO group but at 3% EO was comparable to FO. We conclude that there is no endogenous conversion of SDA to DHA, and that DPA may be associated with limited cardiac benefit.

Highlights

The influence of dietary fats on the pathogenesis of coronary heart disease, congestive heart failure as well as vulnerability to cardiac arrhythmias and sudden cardiac death has been well documented [1,2].In this regard, both the “type” and the “amount” of dietary oils and fats have been identified as important determinants [3,4,5]
Plasma EPA level was significantly increased by the two higher doses of Echium oil (EO) and by all three doses of fish oil (FO) (Table 2)
The present study addressed two key questions relating to tissue fatty acid composition and cardiac arrhythmia outcomes following dietary supplementation with oils rich in n-3 PUFA of different origin

Summary

Introduction

The influence of dietary fats on the pathogenesis of coronary heart disease, congestive heart failure as well as vulnerability to cardiac arrhythmias and sudden cardiac death has been well documented [1,2]. In this regard, both the “type” and the “amount” of dietary oils and fats have been identified as important determinants [3,4,5]. A considerable body of supporting evidence shows that long chain (C ě 20) n-3 polyunsaturated fatty acids (LC n-3 PUFA) derived from marine sources (seafood, fish and microalgae) are effective in affording cardiovascular protection [6,7] more recent analyses have reported inconsistent outcomes [8]. A number of studies [10,11] have reported certain positive cardiovascular health outcomes from consumption of α-linolenic acid (ALA, C18:3n-3), an essential n-3 PUFA widely available from plant-based food sources including certain seed oils (e.g., flax, canola, perilla, chia, walnut, etc.)

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