Omega‐3 polyunsaturated fatty acid supplementation attenuates blood pressure increase at onset of isometric handgrip exercise in healthy young and older humans

Abstract

Aging is associated with alterations of autonomic nerve activity, and dietary intake of omega‐3 polyunsaturated fatty acids, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) found in fish oil (FO), can modulate autonomic nerve activity. However, the effect of omega‐3 polyunsaturated fatty acid consumption on age‐related cardiovascular responses at the onset of isometric handgrip exercise, a time of rapid autonomic adjustments, is unknown. Accordingly, 14 young (25 ± 1 years; mean ± SE) and 15 older (64 ± 2 years) healthy subjects ingested 4 g FO daily for 12 weeks. On pre‐ and postintervention visits, participants performed 15‐sec bouts of isometric handgrip at 10%, 30%, 50%, and 70% maximal voluntary contraction (MVC) while beat‐to‐beat systolic, diastolic, and mean arterial blood pressure (SBP, DBP, MAP; Finometer) and heart rate (HR; electrocardiogram) were recorded. All baseline cardiovascular variables were similar between groups and visits, except DBP was higher in older subjects (P < 0.05). FO increased erythrocyte EPA and DHA content in both groups (P < 0.05). FO attenuated MAP and DBP increases in response to handgrip in both age groups (change from baseline during 70% MVC handgrip pre‐ and post‐FO: young MAPΔ 14 ± 2 mmHg versus 10 ± 2 mmHg, older MAPΔ 14 ± 3 mmHg versus 11 ± 2 mmHg; young DBPΔ 12 ± 1 mmHg versus 7 ± 2 mmHg, older DBPΔ 12 ± 1 mmHg versus 7 ± 1 mmHg; P < 0.05). FO augmented the PP (SBP‐DBP) increase with 70% MVC handgrip in both groups (P < 0.05), but did not alter SBP or HR increases with handgrip. These findings suggest that FO supplementation attenuates MAP and DBP increases at the onset of isometric handgrip exercise in healthy young and older humans.

Differential Effects of Omega-3 Fatty Acid, Docosahexaenoic Acid (DHA), In Animals and Humans

“…In healthy older males, DHA supplementation was found to modulate age-related cardiovascular responses (mean and diastolic arterial blood pressure) in response to exercises utilizing autonomic nerve activity [26]. DHA supplementation lowered the triglyceride levels in both older women [30]and men [27].…”

“…While metabolic rate remained unaffected by DHA supplementation, there was an increase in fatty acid oxidation and a simultaneous decrease in carbohydrate oxidation [25]. Some trials report DHA supplementation attenuated the increase in mean arterial blood pressure [26], decreased triglyceride levels [27] as well as oral glucose tolerance [28] in adults. However, there was no recognizable improvement in cognitive decline [29].…”

Omega-3 polyunsaturated fatty acid supplementation reduces blood pressure but not renal vasoconstrictor response to orthostatic stress in healthy older adults

“…Additionally, data on erythrocyte EPA and DHA content values pre‐ and post‐FO supplementation from 7 of the 10 young subjects and 5 of the 10 older subjects have been previously published in our paper in which the effect of omega‐3 polyunsaturated fatty acid consumption on age‐related cardiovascular responses at the onset of isometric handgrip exercise was examined (Clark et al. ). The focus of this study is the effect of omega‐3 polyunsaturated fatty acid consumption on the renal vasoconstrictor response to orthostatic stress in healthy young and older adults, which has not been investigated to date.…”

“…Data on renal, BP, and HR responses to LBNP without FO supplementation from all 10 young and 10 older subjects have been previously published in our paper in which the effect of aging on the renal vasoconstrictor response to orthostatic stress in healthy adults was examined (Clark et al 2015). Additionally, data on erythrocyte EPA and DHA content values pre-and post-FO supplementation from 7 of the 10 young subjects and 5 of the 10 older subjects have been previously published in our paper in which the effect of omega-3 polyunsaturated fatty acid consumption on age-related cardiovascular responses at the onset of isometric handgrip exercise was examined (Clark et al 2016). The focus of this study is the effect of omega-3 polyunsaturated fatty acid consumption on the renal vasoconstrictor response to orthostatic stress in healthy young and older adults, which has not been investigated to date.…”

“…Mills et al (1990) showed that FO supplementation did not affect the increase in forearm vascular resistance in response to LBNP in healthy young men. We recently showed that FO supplementation attenuates the mean and diastolic BP increases at the onset of isometric handgrip exercise, a time of rapid reflex autonomic adjustments, in both healthy older and young adults (Clark et al 2016). However, the effect of FO consumption on the sympathetically mediated renal vasoconstrictor response to orthostatic stress in older adults has not been determined.…”