Fish Oils seconds aspirin as the most studied material for human health and its health benefits are well known worldwide. The tone and conclusions of the NYT article makes it wonder which hidden forces feel threatened by such natural, healthy and very cost effective way of maintaining human health.
GOED (Global Organization for EPA and DHA – http://www.goedomega3.com) has just reported on this matter stating that it is also a particularly difficult article to address because many of the points made in the article do not cite the underlying studies.
As the article draws misleading conclusions from selective evidence, it is better to review the science supporting the positive cardiovascular benefits linked to omega-3 usage.
For example, the Omega-3s Always a Good Idea web page has useful resources on key scientific studies and can be found at http://alwaysomega3s.com/see/. The Fats of Life website has a number of useful summaries of the evidence supporting the benefits of omega-3 consumption. They can be accessed at http://www.fatsoflife.com/fats-and-health/fat-basics/.
As for the assertions made by the New York Times regarding fish oil, GOED compiled a thorough analysis of each main point in the Times article, as below;
Claim: “Fish Oil Claims Not Supported by Research”
The article leads with the headline that claims made on fish oils are not supported by research, but fails to differentiate between pharmaceutical and dietary supplement claims. The newspaper emphasized that the vast majority of evidence does not show that fish oils lower your risk of heart attacks or strokes, but these claims are not allowed on either dietary supplements or pharmaceuticals, which is a key flaw in the regulatory logic of the article.
The only approved pharmaceutical claim in the US today is for reduction of very high triglycerides, of which there is ample evidence. In the dietary supplement space, there are of course the qualified health claim and the more frequently used structure-function claims that state things like “helps maintain a healthy heart” or “helps maintain healthy blood pressure.” There is ample evidence that EPA and DHA play a beneficial role in the health of the heart, aside from heart attack or stroke risk.
Claim: “The vast majority of clinical trials involving fish oil have found no evidence that it lowers the risk of heart attack and stroke.”
It is true that most of the recent clinical trials have not shown a significant reduction in heart attack or stroke risk, but these recent studies have generally suffered from one or more of the following major design issues, as GOED’s Dr. Aldo Bernasconi has outlined in a review from Fats of Life:
- Not enough participants to detect the effect size researchers wanted to see
- Insufficient dosage and duration for the particular effect
- Not accounting for baseline omega-3 status
- Concomitant medications being taken that already achieve the primary outcome
Despite these flaws in the underlying trials, nearly every meta-analysis published in the last seven years of randomized controlled trials has found that EPA and DHA consumption reduces the risk of coronary death by approximately 10-30%. Even if EPA and DHA consumption does not reduce one’s heart attack or stroke risk, we still consider it beneficial if one’s risk of dying from cardiovascular causes is reduced.
|Meta-Analysis||Studies included||Coronary Death Risk Reduction|
|Wen et al, 2014||14||12% (p=0.003)|
|Casula et al, 2013||11||32% (p<0.05)|
|Kotwal et al, 2012||20||14% (p=0.03)|
|Rizos et al, 2012||20||9% (p=0.01)|
|Kwak et al, 2012||14||9% (p<0.05)|
|Chen et al, 2011||10||19% (p<0.05)|
|Marik et al, 2009||11||13% (p=0.002)|
|Zhao et al, 2009||8||29% (p=0.05)|
|Leon et al, 2008||11||20% (p=0.002)|
Claim: “From 2005 to 2012, at least two dozen rigorous studies of fish oil were published in leading medical journals, most of which looked at whether fish oil could prevent cardiovascular events in high-risk populations. These were people who had a history of heart disease or strong risk factors for it, like high cholesterol, hypertension or Type 2 diabetes. All but two of these studies found that compared with a placebo, fish oil showed no benefit.”
We performed a search through the body of evidence published during this time frame. In Pubmed, we found 136 randomized, controlled trials on EPA and DHA in cardiovascular diseases. Of these, 105 papers (77% of the studies) found a benefit in either the primary or secondary endpoints. It is true that not all of these looked at hard outcomes like cardiovascular events, but they all looked at various markers or outcomes cardiovascular diseases. The data in raw form can be found here.
While this should not be considered a proper scientific review of the evidence, some of the insights found by GOED are interesting. The papers that found no benefits included 22,540 subjects in total, whereas those that showed one or more beneficial effects included 123,848 subjects.
For major cardiovascular events, four clinical trials actually found statistically significant beneficial effects, compared to five that had no effect. The studies finding a benefit included nearly 42,000 patients, compared to 26,000 in those that found no effect. These studies are in very disparate patient populations suffering from a wide variety of cardiovascular diseases, but the statistics are still more interesting and suggestive than the Times asserted.
Furthermore, there are areas where a pretty consistent beneficial effect is demonstrated. There were 26 clinical studies published that measured triglyceride reductions during that period, for instance, and all but one showed statistically significant reduction in TG levels. Those that showed reductions included 15,622 subjects, the one study that did not find a significant reduction included 18 subjects. There were also consistent beneficial effects seen in markers like VLDL cholesterol concentrations, P-selectin, systolic blood pressure, and platelet aggregation.
Claim: “Dr. George Fodor, a cardiologist at the University of Ottawa, outlined flaws in much of this early research [by Bang and Dyerberg], and he concluded that the rate of heart disease among the Inuit was vastly underestimated. But the halo effect around fish oils persists.
Doctor Fodor received a lot of attention last year when his review paper was published questioning the validity of the Greenland Inuit studies in the 1970s. However, his premise was that if these foundational studies were not accurate, then the entire subsequent body of literature was not valid. As Dr. Dyerberg has pointed out, theirs was an observational study that hypothesized a beneficial effect that needed to be confirmed with intervention studies. As noted above, these intervention studies have supported a beneficial reduction in cardiac deaths.
We should also note that while Dr. Fodor’s paper continues to receive a lot of press in the consumer media, not one consumer journalist that wrote about it (including the New York Times) attempted to contact Dr. Dyerberg about his research. Part of our action plan is to arrange a follow up interview for Dr. Dyerberg with the Times.
Claim: “’I think that the era of fish oil as medication could be considered over now,’ said the study’s lead author, Dr. Gianni Tognoni of the Institute for Pharmacological Research in Milan.”
This was not a claim by the Times itself, but is a key point in the article. Again, it should be noted that pharmaceuticals based on fish oil are approved treatments for hypertriglyceridemia, and in Japan also for hyperlipidemia and arteriosclerosis obliterans. Since these are approved pharmaceuticals, clearly the “era of fish oil as medication” is not over. As to whether or not they can reduce the risk of major coronary events in patients that are already being treated for CVD, we know that larger trial sizes are needed to detect an effect that goes above and beyond the cocktail of cardiovascular drugs patients are put on today. Fortunately, there are trials in progress that are specifically designed to explore this now, so we think it is premature to say that this era is over when there are still larger and better-designed trials to come. In addition, there is also at least one large-scale primary prevention trial that will shed more light on the situation.
Full NYT article read at http://mobile.nytimes.com/blogs/well/2015/03/30/fish-oil-claims-not-supported-by-research/?referrer=
We as Tharos remain strong advocates of our daily dose of Omega 3’s.