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Johnston BC, Seivenpiper JL, Vernooij RW, de Souza RJ, Jenkins DJ, Zeraatkar D, Bier DM, Guyatt GH. The Philosophy of Evidence-Based Principles and Practice in Nutrition. Mayo Clin Proc Innov Qual Outcomes 2019; 3:189-199. [PMID: 31193887 PMCID: PMC6543447 DOI: 10.1016/j.mayocpiqo.2019.02.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 02/27/2019] [Indexed: 01/26/2023] Open
Abstract
The practice of evidence-based nutrition involves using the best available nutrition evidence, together with clinical experience, to conscientiously work with patients' values and preferences to help them prevent (sometimes), resolve (sometimes), or cope with (often) problems related to their physical, mental, and social health. This article outlines the 3 fundamental principles of evidence-based practice as applied to the field of clinical nutrition. First, optimal clinical decision making requires awareness of the best available evidence, which ideally will come from unbiased systematic summaries of that evidence. Second, evidence-based nutrition provides guidance on how to decide which evidence is more or less trustworthy-that is, how certain can we be of our patients' prognosis, diagnosis, or of our therapeutic options? Third, evidence alone is never sufficient to make a clinical decision. Decision makers must always trade off the benefits with the risks, burden, and costs associated with alternative management strategies, and, in so doing, consider their patients' unique predicament, including their values and preferences.
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Affiliation(s)
- Bradley C. Johnston
- Department of Community Health and Epidemiology, Dalhousie University, Halifax, NS, Canada
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada
| | - John L. Seivenpiper
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
- Toronto 3D Knowledge Synthesis and Clinical Trials Unit, Clinical Nutrition and Risk Factor Modification Centre, St Michael’s Hospital, Toronto, ON, Canada
- Li Ka Shing Knowledge Institute, Toronto, ON, Canada
| | - Robin W.M. Vernooij
- Department of Community Health and Epidemiology, Dalhousie University, Halifax, NS, Canada
- Department of Research, Netherlands Comprehensive Cancer Organisation, Utrecht, the Netherlands
| | - Russell J. de Souza
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
- Toronto 3D Knowledge Synthesis and Clinical Trials Unit, Clinical Nutrition and Risk Factor Modification Centre, St Michael’s Hospital, Toronto, ON, Canada
- Population Health Research Institute, Hamilton, ON, Canada
| | - David J.A. Jenkins
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
- Toronto 3D Knowledge Synthesis and Clinical Trials Unit, Clinical Nutrition and Risk Factor Modification Centre, St Michael’s Hospital, Toronto, ON, Canada
- Li Ka Shing Knowledge Institute, Toronto, ON, Canada
- Division of Endocrinology and Metabolism, Department of Medicine, St Michael’s Hospital, Toronto, ON, Canada
- Department of Medicine, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Dena Zeraatkar
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada
| | - Dennis M. Bier
- Children's Nutrition Research Center, Baylor College of Medicine, Houston, TX
| | - Gordon H. Guyatt
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada
- Department of Medicine, McMaster University, Hamilton, ON, Canada
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Abstract
The purpose of this review is to consider the effects of the long-chain n-3 fatty acids found in marine foods, EPA and DHA, on risk for CVD, particularly fatal outcomes. It will examine both epidemiological and randomised controlled trial findings. The former studies usually examine associations between the dietary intake or the blood levels of EPA + DHA and CVD outcomes or, on occasion, total mortality. For example, our studies in the Framingham Heart Study and in the Women's Health Initiative Memory Study have demonstrated significant inverse relations between erythrocyte EPA + DHA levels (i.e. the Omega-3 Index) and total mortality. Recent data from the Cardiovascular Health Study reported the same relations between plasma phospholipid n-3 levels and overall healthy ageing. As regards randomised trials, studies in the 1990s and early 2000s were generally supportive of a cardiovascular benefit for fish oils (which contain EPA + DHA), but later trials were generally not able to duplicate these findings, at least for total CVD events. However, when restricted to effects on risk for fatal events, meta-analyses have shown consistent benefits for n-3 treatment. Taken together, the evidence is strong for a cardioprotective effect of EPA + DHA, especially when consumed in sufficient amounts to raise blood levels into healthy ranges. Establishing target EPA + DHA intakes to reduce risk for cardiovascular death is a high priority.
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Harris WS, Tintle NL, Ramachandran VS. Erythrocyte n-6 Fatty Acids and Risk for Cardiovascular Outcomes and Total Mortality in the Framingham Heart Study. Nutrients 2018; 10:nu10122012. [PMID: 30572606 PMCID: PMC6316092 DOI: 10.3390/nu10122012] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 12/11/2018] [Accepted: 12/12/2018] [Indexed: 12/21/2022] Open
Abstract
Background: The prognostic value of erythrocyte levels of n-6 fatty acids (FAs) for total mortality and cardiovascular disease (CVD) outcomes remains an open question. Methods: We examined cardiovascular (CV) outcomes and death in 2500 individuals in the Framingham Heart Study Offspring cohort without prevalent CVD (mean age 66 years, 57% women) as a function of baseline levels of different length n-6 FAs (18 carbon, 20 carbon, and 22 carbon) in the erythrocyte membranes. Clinical outcomes were monitored for up to 9.5 years (median follow up, 7.26 years). Cox proportional hazards models were adjusted for a variety of demographic characteristics, clinical status, and red blood cell (RBC) n-6 and long chain n-3 FA content. Results: There were 245 CV events, 119 coronary heart disease (CHD) events, 105 ischemic strokes, 58 CVD deaths, and 350 deaths from all causes. Few associations between either mortality or CVD outcomes were observed for n-6 FAs, with those that were observed becoming non-significant after adjusting for n-3 FA levels. Conclusions: Higher circulating levels of marine n-3 FA levels are associated with reduced risk for incident CVD and ischemic stroke and for death from CHD and all-causes; however, in the same sample little evidence exists for association with n-6 FAs. Further work is needed to identify a full profile of FAs associated with cardiovascular risk and mortality.
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Affiliation(s)
- William S Harris
- Department of Internal Medicine, Sanford School of Medicine, University of South Dakota, Vermillion, SD 57069, USA.
- OmegaQuant Analytics, LLC, Sioux Falls, SD 57106, USA.
| | - Nathan L Tintle
- Department of Mathematics & Statistics, Dordt College, Sioux Center, IA 51250, USA.
| | - Vasan S Ramachandran
- National Heart Lung and Blood Institute's and Boston University's Framingham Heart Study, Framingham, MA 02118, USA.
- Departments of Cardiology and Preventive Medicine, Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA.
- Department of Biostatistics, Boston University School of Public Health, Boston, MA 02118, USA.
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Harris WS, Luo J, Pottala JV, Espeland MA, Margolis KL, Manson JE, Wang L, Brasky TM, Robinson JG. Red blood cell polyunsaturated fatty acids and mortality in the Women's Health Initiative Memory Study. J Clin Lipidol 2017; 11:250-259.e5. [PMID: 28391893 DOI: 10.1016/j.jacl.2016.12.013] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 12/15/2016] [Accepted: 12/29/2016] [Indexed: 12/15/2022]
Abstract
BACKGROUND The prognostic value of circulating polyunsaturated fatty acid (PUFA) levels is unclear. OBJECTIVES To determine the associations between red blood cell (RBC) PUFA levels and risk for death. METHODS This prospective cohort study included 6501 women aged 65 to 80 years who participated in the Women's Health Initiative Memory Study (enrolment began 1996). RBC PUFA levels were measured at baseline and expressed as a percent of total RBC PUFAs. PUFAs of primary interest were the n-3 PUFAs eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and their sum (the Omega-3 Index). PUFAs of secondary interest included the 2 major n-6 PUFAs, linoleic acid and arachidonic acid, and the PUFA factor score (a calculated variable including 6 PUFAs that accounts for their intercorrelations). The primary outcome was total mortality through August 2014. RESULTS After a median of 14.9 years of follow-up, 1851 women (28.5%) had died. RBC levels of EPA and DHA were higher in the survivors (P < .002 for each). In the fully adjusted models, the hazard ratios (99% confidence intervals) for mortality associated with a 1 standard deviation PUFA increase for total mortality were 0.92 (0.85, 0.98) for the Omega-3 Index, 0.89 (0.82, 0.96) for EPA, 0.93 (0.87, 1.0) for DHA, and 0.76 (0.64, 0.90) for the PUFA factor score. There were no significant associations of alpha-linolenic acid, arachidonic acid or linoleic acid with total mortality. CONCLUSIONS Higher RBC levels of marine n-3 PUFAs were associated with reduced risk for all-cause mortality. These findings support the beneficial relationship between the Omega-3 Index and health outcomes.
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Affiliation(s)
- William S Harris
- Department of Internal Medicine, Sanford School of Medicine, University of South Dakota, Sioux Falls, SD, USA; OmegaQuant Analytics, LLC, Sioux Falls, SD, USA.
| | - Juhua Luo
- Department of Epidemiology and Biostatistics, School of Public Health, Indiana University, Bloomington, IN, USA
| | - James V Pottala
- Department of Internal Medicine, Sanford School of Medicine, University of South Dakota, Sioux Falls, SD, USA
| | - Mark A Espeland
- Department of Biostatistical Sciences, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | | | - Joann E Manson
- Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Lu Wang
- Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Theodore M Brasky
- Comprehensive Cancer Center, Ohio State University, Columbus, OH, USA
| | - Jennifer G Robinson
- Department of Epidemiology, College of Public Health and Department of Internal Medicine, College of Medicine, University of Iowa, Iowa City, IA, USA
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Chaudhary R, Saadin K, Bliden KP, Harris WS, Dinh B, Sharma T, Tantry US, Gurbel PA. Risk factors associated with plasma omega-3 fatty acid levels in patients with suspected coronary artery disease. Prostaglandins Leukot Essent Fatty Acids 2016; 113:40-45. [PMID: 27720039 DOI: 10.1016/j.plefa.2016.08.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 08/16/2016] [Accepted: 08/17/2016] [Indexed: 01/05/2023]
Abstract
INTRODUCTION We sought to determine the associations between plasma eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) levels and various cardiovascular risk factors and with the use of fish oil supplements (FOS). PATIENTS AND METHODS Patients with suspected coronary artery disease (CAD) undergoing cardiac catheterization (n=433) were studied. Serum fatty acid (FA) composition, the concentrations of lipids and biomarkers of oxidative stress, and dietary/lifestyle factors were measured. RESULTS FOS use was associated with a higher plasma EPA+DHA levels (3.7±1.5 vs. 2.6±1.1%, p<0.0001). However, there was no relationship between FOS dose (mg/day) and EPA+DHA levels in 76 patients reporting FOS use (r=-0.21, p=0.07). Lower levels were inversely associated with risk factor profiles including lower ApoB100/ApoA1 ratios (p<0.001). DISCUSSION AND CONCLUSIONS Higher EPA+DHA levels characterized patients with lower CAD risk. The lack of relations between FOS dose and plasma EPA+DHA levels likely reflects uncaptured variability in EPA+DHA content of supplements.
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Affiliation(s)
| | - Katayoon Saadin
- Inova Heart and Vascular Institute, Fairfax, VA, United States
| | - Kevin P Bliden
- Inova Heart and Vascular Institute, Fairfax, VA, United States
| | - William S Harris
- Sanford School of Medicine, University of South Dakota, Sioux Falls, SD, United States; OmegaQuant Analytics LLC, Sioux Falls, SD, United States.
| | - Bao Dinh
- Inova Heart and Vascular Institute, Fairfax, VA, United States
| | - Tushar Sharma
- Sinai Hospital of Baltimore, Baltimore, MD, United States
| | - Udaya S Tantry
- Inova Heart and Vascular Institute, Fairfax, VA, United States
| | - Paul A Gurbel
- Inova Heart and Vascular Institute, Fairfax, VA, United States
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Fenton JI, Gurzell EA, Davidson EA, Harris WS. Red blood cell PUFAs reflect the phospholipid PUFA composition of major organs. Prostaglandins Leukot Essent Fatty Acids 2016; 112:12-23. [PMID: 27637336 DOI: 10.1016/j.plefa.2016.06.004] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Revised: 06/26/2016] [Accepted: 06/28/2016] [Indexed: 02/02/2023]
Abstract
Numerous clinical trials examining the use of omega-3 long chain polyunsaturated fatty acids (n-3 LCPUFAs) on various health outcomes have been conducted, and fish oil remains one of the most widely used nutritional supplements. More recently, studies have begun to utilize the omega-3 index, defined as the sum of EPA+DHA in red blood cells (RBCs), as both a biomarker of n-3 LCPUFA exposure and a potential risk factor for coronary heart disease (CHD). Considerably less research evaluates whether RBC phospholipid fatty acids reflect the phospholipid fatty acid composition of other tissues across increasing intakes of n-3 LCPUFAs. We fed mice diets containing increasing amounts of EPA+DHA, equivalent to current recommendations by the American Heart Association on a percent of energy basis, and analyzed the phospholipid fatty acid composition of various tissues in relation to RBCs. We observed that RBCs, heart, muscle, spleen, lung, and adipose tissues all respond to dietary supplementation with EPA+DHA with increasing n-3 LCPUFA and decreasing n-6 LCPUFA levels. Furthermore, the n-3 LCPUFA profiles of all measured tissues had strong (r>0.7) and significant (p<0.001) correlations to RBCs. Interestingly, we also observed changes in saturated fatty acid (SFA) and monounsaturated fatty acid (MUFA) levels across various tissues in response to increased EPA+DHA intakes despite there being no change in dietary SFA and MUFA. Specifically, there were increases in RBC SFA and spleen MUFA and decreases in heart MUFA. These demonstrate that the RBC, including the omega-3 index, may serve as a marker for the relative levels of n-3 and n-6 LCPUFAs in phospholipids of certain tissues.
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Affiliation(s)
- Jenifer I Fenton
- Department of Food Science and Human Nutrition, Michigan State University, United States; College of Osteopathic Medicine, East Lansing, MI, United States.
| | - Eric A Gurzell
- Department of Food Science and Human Nutrition, Michigan State University, United States
| | - Emily A Davidson
- Department of Food Science and Human Nutrition, Michigan State University, United States
| | - William S Harris
- Sanford School of Medicine, The University of South Dakota, and OmegaQuant, LLC, Sioux Falls, SD, United States
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