Dose-dependent increases in heart rate variability and arterial compliance in overweight and obese adults with DHA-rich fish oil supplementation

Abstract

Heart rate (HR) variability and large arterial compliance can be improved using fish oils. DHA, a component of fish oil, has cardiovascular health benefits, but its effect on HR variability (HRV) and arterial compliance is yet to be quantified. Sixty-seven overweight or obese adults (thirty-six males and thirty-one females; 53 (SEM 2) year; BMI 31·7 (SEM 1·1) kg/m 2 ) were randomly allocated to consume either 6 g/d sunola oil (control; n 17), fish oil (260 mg DHA þ 60 mg EPA per g) at doses of 2 g/d (n 16), 4 g/d (n 17) or 6 g/d (n 17). Blood pressure, HR and compliance of large and small arteries were measured while supine at baseline and after 12 weeks in all participants, and HRV was assessed in a subgroup of forty-six participants. There was no effect of fish oil on blood pressure, small artery compliance or HR. However, the low frequency:high frequency ratio of HRV decreased with increasing doses of fish oil (r 20·34, P¼0·02), while large artery compliance increased (r 0·34, P¼ 0·006). Moreover, the changes in these biomarkers were significantly correlated (r 2 0·31, P¼ 0·04) and may reflect fish oil-induced improvements in arterial function and cardiac autonomic regulation.

Supplementation with n3 Fatty Acid Ethyl Esters Increases Large and Small Artery Elasticity in Obese Adults on a Weight Loss Diet

“…Several studies have examined the effect of fish oil supplementation on artery elasticity measured by pulse contour analysis in humans (17)(18)(19)(20)28). McVeigh et al (17) found that in nonobese individuals with type 2 diabetes, a 6-wk dietary supplementation with fish oils (3 g/d) increased C1 and C2.…”

“…McVeigh et al (17) found that in nonobese individuals with type 2 diabetes, a 6-wk dietary supplementation with fish oils (3 g/d) increased C1 and C2. Wang et al (18) and Sjoberg et al (19) reported that fish oil supplementation improved C1 but had no effect on blood pressures and C2. However, 2 other studies found no effect on C1 and C2 following fish oil supplementation (20,28).…”

“…The ethyl ester forms of n3 fatty acids are considered most biologically effective, because of chemical purity, higher bioavailability, and protection against oxidative stress (15,16). Clinical evidence also indicates that fish oil supplementation improves endothelial function, arterial stiffness, and blood pressure (17)(18)(19)(20)(21)(22). These favorable vascular effects of fish oils may contribute to improved cardiovascular outcomes, as demonstrated in large intervention trials (23,24).…”

The relation of red blood cell fatty acids with vascular stiffness, cardiac structure and left ventricular function: The Framingham Heart Study

“…38 Several interventional studies have assessed the impact of omega-3 supplementation on vascular stiffness. Some groups reported a beneficial effect of omega-3 supplementation on vascular stiffness, [39][40][41][42] whereas others observed no effect. 43,44 Generally, these investigations were of very limited size, and large studies are lacking.…”

The effects of omega-3 polyunsaturated fatty acids on cardiac rhythm: A critical reassessment

“…There have been numerous studies that have confirmed these earlier observations. Both clinical (Christensen et al, 1999;Villa et al, 2002;Dallongesville et al, 2003;Holguin et al, 2005;Christensen & Schmidt, 2007;Carney et al, 2010;Dai et al, 2010;Sjoberg et al, 2010;Christensen, 2011) and experimental studies (Laustiola et al, 1986;Kang & Leaf, 1994;Ayalew-Pervanchon et al, 2007;Billman et al, 2010;Mayyas et al, 2011) report that n-3 PUFA ingestion or acute intravenous administration (Billman et al, 1994) lower HR and increase HRV, suggestive of an increase in cardiac parasympathetic regulation (Billman, 2009. further report that these HR reductions and HRV increases were dose-independent (1-4 mg/kg per day for 3 months), suggesting a low threshold for this effect.…”