Cardiac Autonomic Changes Associated With Fish Oil vs Soy Oil Supplementation in the Elderly


      Omega-3 fatty acid levels are associated with decreased risk for sudden death; however, the protective cardiovascular mechanisms of omega-3 are poorly understood. This study addresses the heart rate variability (HRV) changes in a cohort of elderly subjects randomized to receive either a daily high dose of marine-derived omega-3 fatty acids (fish oil) or a lower daily dose of a plant-derived omega-3 fatty acid (α-linolenic acid) in soy oil


      A total of 58 elderly nursing home residents were randomized to receive 2 g/d of fish oil capsules vs 2 g/d of soy oil capsules, and were subsequently followed up every other day for a period of 6 months with 6-min measurements of HRV while resting supine. An initial control period of 2 months without supplementation was allowed to establish an HRV baseline for each participant


      The average time-and frequency-domain parameters of HRV increased significantly during the supplementation period in both the fish oil and soy oil groups. In the regression model after adjusting for age and mean heart rate, supplementation with fish oil was associated with a significant increase in the high-and low-frequency components, and SD of normal RR intervals (SDNN), whereas only SDNN increased significantly in the soy oil group


      Supplementation with 2 g/d of fish oil was well tolerated and was associated with a significant increase in HRV. Supplementation with 2 g/d of soy oil was associated with a lesser but significant increase in HRV

      Key words


      ALA (α-linolenic acid), CI (confidence interval), HF (high frequency), HRV (heart rate variability), LF (low frequency), p-NN50 (percentage of successive normal RR intervals differing by > 50 ms), r-MSSD (root square root of the mean of the sum of the squares of differences between adjacent intervals), SDNN (SD of normal RR intervals)
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        • Zipes DP
        • Wellens HJ
        Sudden cardiac death.
        Circulation. 1998; 98: 2334-2351
        • Albert CM
        • Hennekens CH
        • O’Donnell CJ
        • et al.
        Fish consumption and risk of sudden cardiac death.
        JAMA. 1998; 279: 23-28
        • Albert CM
        • Campos H
        • Stampfer MJ
        • et al.
        Blood levels of long-chain n-3 fatty acids and the risk of sudden death.
        N Engl J Med. 2002; 346: 1113-1118
        • Gruppo Italiano per lo Studio della Sopravvivenza nell’Infarto miocardico
        Dietary supplementation with n-3 polyunsaturated fatty acids and vitamin E after myocardial infarction: results of the GISSI-Prevenzione trial.
        Lancet. 1999; 354: 447-455
        • Marchioli R
        • Barzi F
        • Bomba E
        • et al.
        Early protection against sudden death by n-3 polyunsaturated fatty acids after myocardial infarction: time-course analysis of the results of the Gruppo Italiano per lo Studio della Sopravvivenza nell’Infarto Miocardico (GISSI)-Prevenzione.
        Circulation. 2002; 105: 1897-1903
        • Leaf A
        • Kang JX
        • Xiao YF
        • et al.
        Clinical prevention of sudden cardiac death by n-3 polyunsaturated fatty acids and mechanism of prevention of arrhythmias by n-3 fish oils.
        Circulation. 2003; 107: 2646-2652
        • Christensen JH
        • Dyerberg J
        • Schmidt EB
        n-3 fatty acids and the risk of sudden cardiac death assessed by 24-hour heart rate variability [letter].
        Lipids. 1999; 34: S197
        • Holguín MM
        • Téllez-Rojo F
        • Hernández M
        • et al.
        Air pollution and heart rate variability among the elderly in Mexico City.
        Epidemiology. 2003; 14: 521-526
        • Kennedy HL
        • Malik M
        • Camm AJ
        Heart rate variability instruments from commercial manufacturers.
        Heart rate variability 1st ed. 1995; 132 (Armonk, NY: Futura Publishing): 127
        • Task Force of the European and the North American Society of Pacing and Electrophysiology
        Heart rate variability: standards of measurement, physiological interpretation, and clinical use.
        Circulation. 1996; 93: 1043-1065
        • Liao D
        • Creason J
        • Shy C
        • et al.
        Daily variation of particulate air pollution and poor cardiac autonomic control in the elderly.
        Environ Health Perspect. 1999; 107: 521-525
        • Hernandez M
        • Romieu I
        • Parra S
        • et al.
        Validity and reproducibility of a food frequency questionnaire to assess dietary intake of women living in Mexico City.
        Salud Publica Mex. 1998; 40: 133-140
        • Xu W
        • Hedeker D
        A random-effects mixture model for classifying treatment response in longitudinal clinical trials.
        J Biopharm Stat. 2001; 11: 253-273
        • Das UN
        Beneficial effect(s) of n-3 fatty acids in cardiovascular diseases: but, why and how?.
        Prostaglandins Leukot Essent Fatty Acids. 2000; 63: 351-362
        • Tsuji H
        • Larson MG
        • Venditti FJ
        • et al.
        Impact of reduced heart rate variability on risk for cardiac events. The Framingham Heart Study.
        Circulation. 1996; 94: 2850-2855
        • Tsuji H
        • Venditti Jr, FJ
        • Manders ES
        • et al.
        Reduced heart rate variability and mortality risk in an elderly cohort. The Framingham Heart Study.
        Circulation. 1994; 90: 878-883
        • Brouwer IA
        • Zock PL
        • van Amelsvoort LG
        • et al.
        Association between n-3 fatty acid status in blood and electrocardiographic predictors of arrhythmia risk in healthy volunteers.
        Am J Cardiol. 2002; 89: 629-631
        • Christensen JH
        • Christensen MS
        • Dyerberg J
        • et al.
        Heart rate variability and fatty acid content of blood cell membranes: a dose-response study with n-3 fatty acids.
        Am J Clin Nutr. 1999; 70: 331-337
        • Supari F
        • Ungerer T
        • Harrison DG
        • et al.
        Fish oil treatment decreases superoxide anions in the myocardium and coronary arteries of atherosclerotic monkeys.
        Circulation. 1995; 91: 1123-1128
        • Christensen JH
        • Christensen MS
        • Toft E
        • et al.
        α-Linonelic acid heart rate variability.
        Nutr Metab Cardiovasc Dis. 2000; 10: 57-61
        • Sinclair A
        • Attar-Bashi NM
        • Li D
        What is the role of α-linolenic acid in mammals?.
        Lipids. 2002; 37: 1113-1123
        • Kris-Ethereton P
        • Eckel RH
        • Howard BV
        AHA science advisory. Lyon Diet Heart Study.
        Circulation. 2001; 103: 1823-1825
        • Lorgeril M
        • Salen P
        • Martin JL
        • et al.
        Mediterranean diet, traditional risk factors and the rate of cardiovascular complications after myocardial infarction: final report of the Lyon Heart Study.
        Circulation. 1999; 99: 779-785
        • Lucini D
        • Milani RV
        • Constantino G
        • et al.
        Effects of cardiac rehabilitation and exercise training on autonomic regulation in patients with coronary artery disease.
        Am Heart J. 2002; 143: 977-983
        • Curtis BM
        • O’Keefe JH
        Autonomic tone cardiovascular risk factor: the danger of chronic fight or flight.
        Mayo Clin Proc. 2002; 77: 45-54