title: Fish oil and neurovascular reactivity to mental stress in humans.
abstract: Omega-3 fatty acids found in fish oil have been suggested to protect against cardiovascular disease, yet underlying mechanisms remain unclear. Despite the well-documented link between mental stress and cardiovascular risk, no study has examined neural cardiovascular reactivity to mental stress after fish oil supplementation. We hypothesized that fish oil would blunt the blood pressure, heart rate (HR), and muscle sympathetic nerve activity (MSNA) responsiveness to mental stress and/or augment limb vasodilation associated with mental stress. Blood pressure, HR, MSNA, forearm vascular conductance (FVC), and calf vascular conductance (CVC) responses were recorded during a 5-min mental stress protocol in 67 nonhypertensive subjects before and after 8 wk of fish oil (n = 34) or placebo supplementation (n = 33). Fish oil blunted HR reactivity to mental stress (group × condition × time interactions, P = 0.012) but did not alter blood pressure reactivity to mental stress (interactions, P > 0.05). Fish oil blunted total MSNA reactivity to mental stress (interaction, P = 0.039) but did not alter MSNA burst frequency and burst incidence reactivity (interactions, P > 0.05). Finally, fish oil significantly blunted CVC reactivity to mental stress (interaction, P = 0.013) but did not alter FVC reactivity (interaction, P > 0.05). In conclusion, 8 wk of fish oil supplementation significantly attenuated both HR and total MSNA reactivity to mental stress and elicited a paradoxical blunting of calf vascular conductance. These findings support and extend the growing evidence that fish oil may have positive health benefits regarding neural cardiovascular control in humans.
authors: Department of Kinesiology and Integrative Physiology, Michigan Technological University, 1400 Townsend Dr., Houghton, MI 49931, USA. jcarter@mtu.edu
authors: Jason R
authors: JR
authors: Carter
authors: Christopher E
authors: CE
authors: Schwartz
authors: Huan
authors: H
authors: Yang
authors: Michael J
authors: MJ
authors: Joyner
mesh_terms: D000328:Adult; D001794:Blood Pressure / Q000187:drug effects; D004311:Double-Blind Method; D005260:Female; D005395:Fish Oils / Q000008:administration & dosage / Q000494:pharmacology*; D005542:Forearm / Q000098:blood supply; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007866:Leg / Q000098:blood supply / Q000294:innervation; D008297:Male; D018482:Muscle, Skeletal / Q000098:blood supply* / Q000294:innervation; D013315:Stress, Psychological / Q000188:drug therapy*; D013564:Sympathetic Nervous System / Q000187:drug effects; D014655:Vascular Resistance / Q000187:drug effects* / Q000502:physiology; D055815:Young Adult
chemical_list: D005395:Fish Oils