September 17th, 2012
by Mike T Nelson · Filed Under: nutrition
I have a great guest blog for you today. Recently, the media seems to have jumped all aboard the anti fish oil bandwagon full stop. A recent study  stated that perhaps fish oil is not that good, and the media is already foaming at the mouth ready starting the finger shaking and say that all those supplement are truly evil.
But, it is true? I doubt it and to back me up I asked my good buddy Dr. Hector Lopez to shed some light on this topic. Look for a geeky academic book chapter due out early next year from both of us on the topic of “Effects of Dietary Fat on Health and Performance” along with our friend Dr. Doug Bibus.
In the meantime, here is the video from ABC News
Take it away Dr. Hector. —Mike T Nelson
I have been asked for my professional opinion on the recent attention drawn to the September 2012 systematic review and meta-analysis published in the prestigious Journal of the American Medical Association (JAMA) by Rizos EC et al .
As you can imagine, the last couple of days have been very busy answering emails/calls from various stakeholders in the dietary supplement and omega-3 fish oil industries. The stakeholders range from friends and family to fellow scientists and colleagues, to high-level executives and principals of client companies. I have a few things to say about the manner (at times disingenuous) in which the meta-analysis has been misrepresented.
Multiple video segments from major media outlets have had even quoted some of their experts as saying,
“they would rather the public spend their money elsewhere as the proof is in with this study.”
Perhaps they would feel more at ease suggesting the consumption of another box of “whole-grain” yet low fiber, highly processed cereal, “natural fruit juice”, or better yet, “linoleate-rich vegetable oils full of omega-6 fatty acids” (hey they are polyunsaturated too, right)?
Better Than Fish Oil?
I don’t mind that the media shares their opinion, but at the very least, do what is possible to educate the very audience that they are obviously trying to persuade.
I find it hard to believe the public would not be interested in some other material facts to allow consumers to make an informed decision, so here are my top 11 facts that the media ignored.
1) Out of over 3600 clinical studies and citations retrieved, ONLY 20 were used in this “analysis.”
2) The absence of statistically significant association in these 20 studies between omega-3 and CVD (cardiovascular disease) endpoints does not prove that a significant diminution of CVD with omega-3 does not occur.
3) These 20 studies were on a diseased population, that were already using multiple cardiovascular drugs such as beta-blockers, statins, niacin, fibrates, resins, and anti-thrombotics…all of which clearly confound outcomes/ endpoints of interest to dilute and washout effects of LC-omega-3 PUFA. Fish oil at this low dose was likely “too little, too late” to show any statistically significant benefit.
4) A similar meta-analysis was published earlier this year on secondary prevention …clearly, the older studies showed benefit as these patients were likely not on as many cardio-protective medications. Hence, their was less of a “washout” in effect size.
Don’t Eat Me?
5) A mean dose of less than 1.4g of EPA + DHA was used in all 20 studies. This dose is typically far too low to compensate for the overabundance of omega-6 PUFA and imbalance in omega-6:omega-3 consumption in standard western diets. It’s no surprise that previous studies showing benefit of omega-3 fish oil in heart disease have utilized at least 2g of EPA + DHA. Future studies should also take this into consideration. In addition, future studies should attempt to carry out prospective data collection beyond 2 years.
6) No mention, consideration or control for background dietary intake of EPA/DHA or tissue FA profiles. The researchers did not control for this important variable within each individual study included in this meta-analysis, and as a result there is no way to determine if placebo groups already had sufficient levels of omega-3 in their diet or tissue making it harder to demonstrate treatment effects of fish oil.
7) Clearly, these 20 studies were not adequately powered to detect changes in the CVD endpoints with omega-3 LC-PUFA, even if they were in fact present.
The Evil Fish Oil Capsule
8 ) Despite all these flaws, based on the Confidence Interval data (Mike’s note – geek speak for a way to use stats to determine a “real” event or not), there was still a “trend” toward cardioprotection via (sudden death, myocardial infarction aka heart attack, cardiac and all-cause mortality).
In English, the data in this article still trended toward decreased risk of various cardiovascular disease outcomes. However, headlines wouldn’t be juicy enough though.
9) Sure, most Americans should eat more fish (in their whole food diet), but honestly, how many actually do? Where is the press coverage or meta-analyses looking at PCB/ Dioxin/ Persistent Organic Pollutants/ and Heavy Metal exposure? I suppose when this omega-3 story dies down, the environmental toxin exposure story can quickly fill that void.
10) The findings of this selective meta-analysis are in direct conflict with the totality of the scientific evidence that demonstrates a cardiovascular benefit from EPA and DHA in healthy populations, as well as in many of the populations with pre-existing CVD [3-10].
Consumers and health care providers alike continue to feel confident in the use of high-quality omega-3 fish oil for not only cardiovascular benefit, but also for supporting the health of just about every organ system in the body. The long chain omega-3 essential fatty acids found in fish oil are critical for everything from the cardiovascular system to the brain and nervous system, immune system, skin, joint and musculoskeletal tissues, to carbohydrate and lipid metabolism and beyond [11-19].
11) Finally, there is the issue of the potential mega-misrepresentation created by meta-analyses. It is evident that study selection criteria, as well as data extraction/synthesis may allow researchers to make assumptions of consistency in the design individual studies included in the meta-analysis.
As such, these assumptions may lead the authors –or worse, the less discerning media– to drawing erroneous conclusions.
Translation? They got it wrong!
These erroneous conclusions then get virally disseminated throughout the general public. Doesn’t this string of events sound eerily familiar?
Hector Lopez, MD, CSCS, FAAPMR
Bio: Dr. Lopez is recognized for applying his uniquely diverse expertise in spine and sports medicine, endocrinology and metabolism, nutrition & exercise science, and clinical research to improving not only the health and quality of life in his patients, but also athletic performance in recreational and elite athletes. Dr. Lopez received his specialty training at the world-renowned Northwestern University Feinberg School of Medicine-Rehabilitation Institute of Chicago. He is currently a principal & the Chief Medical Officer of the Center for Applied Health Sciences- a multidisciplinary Clinical Research Organization in Ohio, and Supplement Safety Solutions- a Nutravigilance, Quality Assurance/Safety and Regulatory consulting company focused on dietary supplement/nutraceutical industry. He is an international speaker, author of popular press and peer-reviewed scientific journal articles, product developer, and consultant for the nutritional supplement industry, as well as to professional athletes from the NFL, NBA, MLB, NHL and Martial Arts. Get more from him at Twitter:@DrHectorLopez www.drhectorlopez.com
Rizos EC, Ntzani EE, Bika E, Kostapanos MS, and Elisaf MS. Association Between Omega-3 Fatty Acid Supplementation and Risk of Major Cardiovascular Disease Events. A systematic review and meta-analysis. JAMA. 2012; 308(10):1024-1033.
Kwak SM, Myung SK, Lee YJ, Seo HG; Korean Meta-analysis Study Group. Efficacy of omega-3 fatty acid supplements (eicosapentaenoic acid and docosahexaenoic acid) in the secondary prevention of cardiovascular disease: a meta-analysis of randomized, double-blind, placebo-controlled trials. Arch Intern Med. 2012 May 14;172(9):686-94.
Yokoyama M, Origasa H, et al. JELIS Investigators. Effects of eicosapentaenoic acid on cardiovascular events in Japanese patients with hypercholesterolemia: rationale, design, and baseline characteristics of the Japan EPA Lipid Intervention Study (JELIS). Am Heart J. 2003;146:613-620.
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Burr ML, Fehily AM, Gilbert JF, et al. Effects of changes in fat, fish and fibre intakes on death and myocardial reinfarction: Diet and Reinfarction Trail (DART). Lancet. 1989;2:757-761.
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Marchioli R, Levantesi G, Macchia A, et al. GISSI-Prevenzione Investigators. Antiarrhythmic mechanisms of n-3 PUFA and the results of the GISSI-Prevenzione trial. J Membr Biol. 2005 Jul;206(2):117-28.
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Mills JD, Hadley K, Bailes JE. Dietary supplementation with the omega-3 fatty acid docosahexaenoic acid in traumatic brain injury. Neurosurgery. 2011. Feb;68(2):474-81.
Black KL, Culp BR, Randall OS, Lands WEM. The protective effects of dietary fish oil and focal cerebral infarction. Prostaglandins. 1979;3:257-268.
Milte CM, Sinn N, Street SJ, Buckley JD, Coates AM, Howe PR. Erythrocyte polyunsaturated fatty acid status, memory, cognition and mood in older adults with mild cognitive impairment and healthy controls. Prostaglandins Leukot Essent Fatty Acids. 2011 May-Jun;84(5-6):153-61.
Kremer JM. Effects of modulation of inflammatory and immune parameters in patients with rheumatic and inflammatory disease receiving dietary supplementation of n-3 and n-6 fatty acids. Lipids. 1996;31:243S-247S.
Smith GI, Atherton P, Reeds DN, Mohammed BS, Rankin D, Rennie MJ, Mittendorfer B. Dietary omega-3 fatty acid supplementation increases the rate of muscle protein synthesis in older adults: a randomized controlled trial. Am J Clin Nutr. 2011 Feb;93(2):402-12.
Rodacki CL, Rodacki AL, Pereira G, et al. Fish-oil supplementation enhances the effects of strength training in elderly women. Am J Clin Nutr. 2012 Feb;95(2):428-36.
Sinn N, Milte CM, Street SJ, et al. Effects of n-3 fatty acids, EPA v. DHA, on depressive symptoms, quality of life, memory and executive function in older adults with mild cognitive impairment: a 6-month randomised controlled trial. Br J Nutr. 2011 Sep 20:1-12.
A huge thanks to Dr. Hector Lopez for his commentary.
What do you think? Post up in the comments below!
Mike T Nelson