Still More Evidence That Fish Oil Supplements Do Not Prevent Cardiovascular Disease

Avid readers of the skeptical cardiologist know that he is not an advocate of fish oil supplements.

One of my first posts (1/2013) was devoted to taking down the mammoth OTC fish oil industry because recent scientific evidence was clearly showing no benefit for fish oil pills.

I concluded:

", the bottom line on fish oil supplements is that  the most 
recent scientific evidence does not support any role for them  inpreventing heart attack, stroke, or death. There are potential 
down sides to taking them, including contaminants and the impact on the marine ecosystem. I don’t take them and I advise my
patients to avoid them (unless they have triglyceride levels 
over 500.)"

Despite a lack of evidence supporting taking them, the fish oil business continues to grow,  buttressed by multiple internet sites promoting various types of fish oil (and more recently krill oil)  for any and all ailments and a belief in the power of “omega-3 fatty acids”.

Another Meta-Analysis Concludes No Benefit To Fish Oil Supplements

A publication this month evaluated the 10 randomized controlled trials involving 77 917 thousand individuals that have studied fish oil supplements in preventing heart disease. The writers concluded that fish oil supplements do not significantly prevent any cardiovascular outcomes under any scenario.

It was written by a group with the ominous title of “The Omega-3 Treatment Trialists’ Collaboration.”

The Omega-3 Treatment Trialists’ Collaboration was established to conduct a collaborative meta-analysis based on aggregated study-level data obtained from the principal investigators of all large randomized clinical trials of omega-3 FA supplements for the prevention of cardiovascular disease, using a prespecified protocol and analysis plan. The aims of this meta-analysis were to assess the associations of supplementation with omega-3 FAs on (1) fatal CHD, nonfatal MI, stroke, major vascular events, and all-cause mortality and (2) major vascular events in prespecified subgroups.

The authors conclusions:

. Randomization to omega-3 fatty acid supplementation (eicosapentaenoic acid dose range, 226-1800 mg/d) had no significant associations with coronary heart disease death (rate ratio [RR], 0.93; 99% CI, 0.83-1.03; P = .05), nonfatal myocardial infarction (RR, 0.97; 99% CI, 0.87-1.08; P = .43) or any coronary heart disease events (RR, 0.96; 95% CI, 0.90-1.01; P = .12). Neither did randomization to omega-3 fatty acid supplementation have any significant associations with major vascular events (RR, 0.97; 95% CI, 0.93-1.01; P = .10), overall or in any subgroups, including subgroups composed of persons with prior coronary heart disease, diabetes, lipid levels greater than a given cutoff level, or statin use.

Nothing. Nada. No benefit.

There is clearly no reason to take fish oil supplements to prevent cardiovascular disease!

American Heart Association Sheepishly Recommends Fish Oil Supplements

If the science was conclusive on this in 2013 why did the American Heart Association (AHA) issue an “advisory” in 2017  suggesting that the use of omega-3 FAs for prevention of coronary heart disease (CHD) is probably justified in individuals with prior CHD and those with heart failure and reduced ejection fractions?

The AHA advisory is clearly misguided and relies heavily in its discussion on a 2012 meta-analysis from Rizos, et al. published in 2012.

Oddly, this is the study that prompted me to write my first fish oil post in 2013

The AHA advisory totally distorts the completely negative conclusions of the Rizos meta-analysis, writing:

A meta-analysis published in 2012 examined the effects of omega-3 PUFA supplementation and dietary intake in 20 RCTs that enrolled patients at high CVD risk or prevalent CHD and patients with an implantable cardioverter-defibrillator (total n=68 680). That meta-analysis demonstrated a reduction in CHD death (RR, 0.91; 95% CI, 0.85–0.98), possibly as the result of a lower risk of SCD (RR, 0.87; 95% CI, 0.75–1.01).11

Strangely enough, if you look at the conclusions of Rizos, et al. they are

No statistically significant association was observed with all-cause mortality (RR, 0.96; 95% CI, 0.91 to 1.02; risk reduction [RD] -0.004, 95% CI, -0.01 to 0.02), cardiac death (RR, 0.91; 95% CI, 0.85 to 0.98; RD, -0.01; 95% CI, -0.02 to 0.00), sudden death (RR, 0.87; 95% CI, 0.75 to 1.01; RD, -0.003; 95% CI, -0.012 to 0.006), myocardial infarction (RR, 0.89; 95% CI, 0.76 to 1.04; RD, -0.002; 95% CI, -0.007 to 0.002), and stroke (RR, 1.05; 95% CI, 0.93 to 1.18; RD, 0.001; 95% CI, -0.002 to 0.004) when all supplement studies were considered.

Nothing. Nada. No significant benefit!

The AHA was so confused by their own advisory that in the AHA news release on the article they quote Dr. Robert Eckel, a past AHA president as saying he remains “underwhelmed” by the current clinical trials.

“In the present environment of evidence-based risk reduction, I don’t think the data really indicate that fish oil supplementation is needed under most  circumstances.”

The end of the AHA news article goes on to quote Eckel as indicating he doesn’t prescribe fish oil supplements and the science advisory won’t change his practice:

Eckel said he doesn’t prescribe fish oil supplements to people who have had coronary events, and the new science advisory won’t change that. “It’s reasonable, but reasonable isn’t a solid take-home message that you should do it,” he said.

AHA: Wrong On Coconut Oil and Fish Oil

It’s hard for me to understand why the AHA gets so many things wrong in their scientific advisories. In the case of the recent misguided attack on coconut oil , their ongoing vilification of all saturated fats, and their support for fish oil supplements I don’t see evidence for industry influence. The authors of the fish oil supplement advisory do not report any financial conflicts of interest.

There is, however, one bias that is very hard to measure which could be playing a role: that is the bias to agree with what one has previously recommended.  The AHA issued an advisory in 2002 recommending that people take fish oil. Changing that recommendation would mean admitting that they were wrong and that they had contributed to the growth of a 12 billion dollar industry serving no purpose.

Personally, I am aware of this kind of bias in my own writing and strive to be open to new data and publications that challenge what I personally believe or have publicly recommended.

In the case of fish oil supplements for preventing cardiovascular disease, however, the most recent data supports strongly what I wrote in 2013:

Don’t take fish oil supplements to prevent heart disease.

Americans want a “magic-bullet” type pill to take to ward off aging and the diseases associated with it. There isn’t one. Instead of buying pills and foods manipulated and processed by the food industry which promise better health, eat real food (including fish) eat a lot of plants and don’t eat too much.

Piscinely Yours,

-ACP

N.B. I have no patients on the two prescription fish oil supplements available, Lovaza and Vascepa. I wrote about Vascepa here

Below is an excerpt:

Like the first prescription fish oil available in the US, Lovaza, VASCEPA is only approved by the FDA for treatment of very high triglycerides (>500 mg/dl).

This is a very small market compared to the millions of individuals taking fish oil thinking that  it is preventing heart disease.

The company that makes Vascepa (Amrin;$AMRN)would also like to have physicians prescribe it to their patients who have mildly or moderatelyelevated triglycerides between 200 and 500 which some estimate as up to 1/3 of the population.

The company has a study that shows that Vascepa lowers triglycerides in patients with such mildly to moderately elevated triglycerides but the FDA did not approve it for that indication.

Given the huge numbers of patients with trigs slightly above normal, before approving an expensive new drug, the FDA thought, it would be nice to know that the drug is actually helping prevent heart attacks and strokes or prolonging life.

After all, we don’t really care about high triglycerides unless they are causing problems and we don’t care about lowering them unless we can show we are reducing the frequency of those problems.

Data do not exist to say that lowering triglycerides in the mild to moderate range  by any drug lowers heart attack risk.

In the past if a company promoted their drug for off-label usage they could be fined by the FDA but Amarin went to court and obtained the right to promote Vascepa to physicians for triglycerides between 200 and 500.

Consequently, you may find your doctor prescribing this drug to you. If you do, I suggest you ask him if he recently had a free lunch or dinner provided by Amarin, has stock in the company (Vascepa is the sole drug made by Amrin and its stock price fluctuates wildly depending on sales and news about Vascepa) or gives talks for Amarin.

If he answers no to all of the above then, hopefully, your triglycerides are over 500.

.

 

 

 

 

12 thoughts on “Still More Evidence That Fish Oil Supplements Do Not Prevent Cardiovascular Disease”

  1. Dr, i would caution you on i terpetation of this metadata study aith such a wide range of dosages. The dosage must be high enough to alter the epa aa ratio. Wait another 6 months, and you will have the results of a double blind randomized trial of the effectiveness of 4 grams per day of vascepa (EPA).
    If it fails to show benefit, I would think the AHA would reverse their recommendations. if it succeds, how long will it take cardiologists to recommend it?

  2. You don’t mention docosahexaenoic acid. Have you looked into this component of fish oil?
    I just did my own little meta. Having read the first twenty abstracts I can say that the results are overwhelmingly positive-ish for CVD.
    I eat plenty of fatty cold-ocean fish instead of either eicosapentaenoic or docosahexaenoic acids on their own. Don’t plan to stop.
    https://www.ncbi.nlm.nih.gov/pubmed?term=(docosahexaenoic%5BTitle%2FAbstract%5D)%20AND%20cardiovascular%5BTitle%2FAbstract%5D

  3. Hi from Canada,
    It is to be recognised that nobody is forced to share on the Web… So thank you for taking your time and energy to inform, educate and stimulate people making more healty decisions. What you do here is very appreciated.
    Best regards doctor and good health to you!

    Frank

  4. I wish to take issue with the misleading picture on this blog. I have been to St Louis , sir, and it does not look like that picture on it’s best day!

    ________________________________

  5. Your blog is the best – thank you for all your amazingly helpful info. I take 4,000 mg of fish oil (with a high epa and dha content) based on a recommendation from my eye doctor for dry eye. It does actually (after about a month) make my contacts much more comfortable. If there are any other benefits to it, I don’t know – I do appreciate knowing that it’s definitely not a heart support supplement.

  6. Love your stuff but you are only partially correct here. Yes , in the statin era, “fish oils” dont appear to reduce cvd risk on top of ubiquitous statin use. The meta analyses support this. But EPA ONLY Omega 3’s in > 2 gram/day doses, DO ! As we know from the JELIS trial ( HUGE trial with 19% MACE reduction when adding 2 grams/day EPA only to statin controlled NON hypertriglyceridemic patients (avg trigs 153) , and 53% MACE reduction when trigs are >150 AND HDL-C <40 ("metsyn subset" ) and the CHERRY trial (slowing of plaque progression with 2 grams of EPA only added to statin background) , EPA only reduces both clinical events and disease progression on top of background statin therapy . we anxiously await the results of the REDUCE-IT trial, with 4 grams of EPA only Vascepa on top of statin therpay in hypertriglycerdiemic patients. You're right- "fish oils dont work". EPA only DOES ! (there are many theoretical and in vivi in vitro reasons why EPA only is superior to combined EPA/DHA products, that ive no time to list here.

    1. Also, realize that several of the BETTER “fish oil” trials (OMEGA and ORIGIN) did not meet their primary endpoints because they selected the wrong patients ( trigs were < 200 mg/dl) and used LOW dose" fish oils" for brief periods (instead of higher dose EPA only omega 3's for longer periods of time.)

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