Fish And Not Fish Oil
Article: n–3 Fatty Acids and Cardiovascular Events after Myocardial Infarction
Daan Kromhout, M.P.H., Ph.D., Erik J. Giltay, M.D., Ph.D., and Johanna M. Geleijnse, Ph.D. for the Alpha Omega Trial Group
August 29, 2010 (10.1056/NEJMoa1003603)
Conclusion: Low-dose supplementation with EPA–DHA or ALA did not significantly reduce the rate of major cardiovascular events among patients who had had a myocardial infarction and who were receiving state-of-the-art antihypertensive, antithrombotic, and lipid-modifying therapy. (Funded by the Netherlands Heart Foundation and others; ClinicalTrials.gov number, NCT00127452.)
Well that’s what it looks like on the website of the New England Journal of Medicine. The take away message, I’ve found this on several newspaper front pages, was that taking omega 3’s had no benefit. I think this is true but let’s look a little further at the study. The net effect of this article will likely turn out to be bad even though I believe the results. That net bad effect is what I want to explain as understanding it will help you through the process of interpreting many such studies, further seeing the politicalization of science and will help you to avoid downstream catastrophic consequences following such advice.
First a little background: In the annals of nutritional science only dairy has been more vilified than beef. Eat beef, you die. “China Study,” Dr. Dean Ornish, etc; beef is bad. Nutritional studies have for decades lumped everything from bologna and hot dogs to field-kill Elk in the same category. Food diaries have been the primary tool to analyze the link between diet and disease. Well the nutritional studies have finally done the sensible thing and separated out processed meats, like bologna and hot dogs, from the category of ‘meat’ on diet diaries. Only recently has the category ‘meat’ been further divided into ‘beef’, ‘pork’, etc. From the old confused categories and the imputed health risk of ‘meat’ various theories have been put forward to account for the ostensible dangers of ‘meat.’ Cholesterol, saturated fats, ‘gut rot’ (I’m not kidding), etc. Better recent studies have finally picked out the net effect of saturated fat, one of the supposed mechanisms of harm from beef; no problem there. The dietary contribution of ‘meat’ and ‘beef’ to cholesterol palls in comparison to the body’s production of cholesterol so that cause of harm has been discounted. With the exception of those who ascribe to the theory that the weight of Elvis Presley’s colon killed him no one anymore believes the ‘gut rot’ version. To add insult to injury to those who claim beef is bad when these variables are pulled out there remains no statistical harm that can be attributed to beef. Well now they are trotting out an old hypothesis that beef really does harm- where is it?- because of excess iron loads in meat eaters. Iron overload and its contribution to disease is credible- long digression here that I will avoid but those who were pushing the cholesterol hypothesis dismissed the iron connection more than a decade ago. Well now it is back because the ‘desire,’ for that is what it looks like, for ‘beef’ to be bad is so powerful. Let me recapitulate: for those who meticulously follow the nutritional literature on beef that the assumption of harm was first based on ‘rotting’ in the gut, then on cholesterol, then saturated fat, and now that it has been looked at in isolation and no harm been found new mechanisms of why it ‘should’ cause harm are being adduced and the ‘new mechanism’ is an old idea.Iron overload is a real problem for some people but due to inherent genetics rather than beef intake. (Be sure to periodically check your iron load, by the way.) Of course low iron is a more common problem but nothing stops the relentless pursuit of the original bad hypothesis. After all many careers have been built on the evils of meat. And dairy.
OK, now keep that brief intellectual history of our understanding of meat in mind as we look at the history of omega 3’s. 25 years ago the primary author, Daan Kromhout (Swedish) of the recent NEJM article in question, published an interesting article in the NEJM showing a reduction in fatal and non-fatal heart attacks in those who ate at least one serving of fatty fish per week. Hmmm. We are off and running; can’t be the fish, must be a drug in there somewhere! Make no mistake, long chain omega 3’s (EPA/HLA, not ALA) are essential fats; we would die without them. Still from eating fish to the fats were the good guys is a long and likely false extrapolation. Sure omega 3’s have been shown to be helpful; you need the blasted things but note needing them and they should be seen as a drug or supplement is a non-sequitur. Keep in mind the original fish benefit may have been everything from the exercise of going to the fish market to a substitution effect, that is, the population ate fish instead of, oh, I don’t know maybe Heath bars. Not likely that but very likely bread or oats or bologna. In that light the recent article was a riot of foolishness. They mixed EPA/DHA, ‘fish oils,’ and ALA, ‘flax seed oil,’ into margarine depleted of oleic acid (a saturated fat common to the original margarine) and had those randomized to EPA/DHA or EPA/DHA/ALA; and had those consume their low dose of ‘fish oil’ on slices of bread, which was not randomized by the way- you were thinking ‘big carb load’ right? These were people 4 years after a first heart attack, and on antithrombotic, lipid lowering and antihypertensive medications. Now, there is no real comparison between that long ago fish study and this one except that fish, and every other wild-living, wild-feeding animal, have omega 3’s and there were some omega 3’s in the margarine given to people who were on at least 3, sometimes as many as 6 drugs.
The winnowing process in pursuit of health has now irreversibly eliminated fish from the plate and palette of those who want to stay healthy. You don’t think this is what is in play here? The commentators are already congratulating themselves on the wonders of modern pharmacy. “You don’t need no stinking fish.” Or fish oils. Just take your Lipitor. Or whatever they will be selling in the future. They believe this stuff. I recommend you do not.
Let me be clear: I would personally be willing to bet that Dr. Kronhout is an intelligent and honorable man beholden to nothing other than the human condition. His honor is not in question here. What is in question is the frailty of science to comprehend the complexity of human biology and to be wary of, here is a convenient and sturdy whipping boy; to be wary of reductionist approaches to your health and well-being.
Eat complex, whole, real food.
“Do not go gentle into that good night,
Old age should burn and rage at close of day;
Rage, rage against the dying of the light…” Dylan Thomas
Smile, God Speed,