7 reasons why recent news on fish oil has been negative
Lately, there’s been nothing but bad news about fish oil.
At last check, there were over 22,000 separate published studies on fish oil, most of it published in the last decade.
If there is such an explosive increase in scientific proof in support of fish oil’s benefits, then what gives?
Here are a few reasons reasons why:
1. Fear sells. Information doesn’t.
Survival is a very primal human instinct. And fear relates to our survival. TV producers aren’t trying to scare you. They’re just doing what works.
If CNN’s top health report was ‘Yet another study validates EPA Omega-3’s effect on health,’ you’d switch to the Kardashian Channel. That’s what sells. Not judging. Here are some cat videos.
Heck, even science-savvy Ira Flatow on NPR’s Science Friday, seemingly sat there filing his nails allowing scaremongering to go unquestioned.
Just last week, we got what may possibly be the best news on fish oil in a long time – a review of 70 studies showed that fish oil supports healthy blood pressure*. A brilliant piece of science commissioned by the equally brilliant people at GOED. The cricket-chirping silence from the media was noted by the savvier-than-Flatow Stephen Daniells in this piece.
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. Individual results may vary. Clinical research suggests that 2000-3000 mg Omega-3 per day when used as part of healthy diet and exercise may help maintain healthy blood pressure.
2. The cocktail effect
Ever try speaking softly in a crowded sports bar? It doesn’t work. Similar situation with heart meds and Omega-3 studies.
Patients in many fish oil studies are also taking mega-cocktails of several different powerful cardiovascular drugs. This is called combination therapy, a throw-everything-at-the-wall approach.
Back in the 80s and 90s, when virtually every study on fish oil was positive, people weren’t exposed to aggressive background medical treatment. Back then, many of these drugs weren’t even around. So, in a polypill world, it is almost impossible for fish oil or even a new, powerful stand-alone drug to provide enough benefit to rise above the noise.
Six recent trials showed little or no benefit to taking Omega-3 and all of them had very high background medical treatment with statins, antihypertensives and anticoagulants.
This is a huge problem but it does not mean that Omega-3 is ineffective.
3. People are aware of (and consuming) Omega-3
People have begun eating Omega-3 fortified foods.
There is Omega-3 in milk, eggs, orange juice, bread, yogurt and anything else that marketers can sprinkle a little Omega-3 into.
If you’re already getting Omega-3 from several sources in your diet, it becomes difficult to show benefit with a little more added Omega-3. ‘High background fish and fish oil supplement‘ use among study participants has been noted by several researchers.
William Harris, a professor of medicine at the Sanford School of Medicine at the University of South Dakota says that as more people consume fish and other products with omega-3 in it, the harder it is to show a benefit because there is no true placebo group.
4. High Omega-6 consumption
Omega-6 and Omega-3 fats have opposing ying-yang effects in your body.
Our natural (and ideal) ratio between these two groups of fatty acids is roughly 1 to 1. But even 2 or 3 times as much Omega-6 is fine. But modern diets are as much as 15 or 20 times in favor of Omega-6.
This extreme imbalance may be part of the reason why we need more Omega-3 ying to balance the Omega-6 yang.
Most Omega-3 benefits often trace back to moderating or undoing the damage from excess Omega-6*. And Omega-6 is a precursor for several potentially unhealthy compounds. The health effects of low or moderate levels of Omega-3 are likely to be drowned out due to the unnaturally high levels of Omega-6 in our diet…again, not unlike speaking softly in a loud sports bar.*
Given that our Omega-6 consumption has dramatically increased since the 1970s, isn’t it logical to assume that you’d need higher amount of Omega-3 to notice a health benefit?
Some researchers have started accounting for high dietary Omega-6 intake. But most have not.
5. Omega-3 Dosage is too low
If you want to show an effect, you may need to take higher doses. Simple concept.
But not all studies use effective doses. It does not mean Omega-3 is a dud. It just means that at that low dosage, the study showed no statistical benefit.
Dr. Barry Sears of Zone Diet fame has beat this point to death. Or has he?
This is a pet peeve. I could rant for days.
This should be a litmus test for all graduate students defending their thesis: can you kill pirates by cranking up your thermostat? (Instead, they asked me about standard deviation and secondary differential equations…pshaw! Thanks, Dr. Cornell!)
Last year’s charmingly flawed ‘fish oil supplements cause prostate cancer‘ study confused correlation with causation.
Theodore Brasky, the lead author of the study, I’m told, keeps his office at a toasty 110 degrees. When faced with a room full of scientists, he offered a plausible explanation that supplement users are more likely to visit their doctors and therefore more likely to be diagnosed earlier with prostate cancer. That doesn’t excuse the fact that his original headline-grabbing study didn’t include fish oil supplementation.
At the same conference, when Dr. Dominik Alexander, an epidemiologist, reviewed the same data from the same prostate cancer study. He described prostate cancer risk from fish oil consumption as ‘Not much. No increased risk. No decreased risk. Nothing much is going on. A non-statistically-significant finding.‘
Not the message we heard on TV last year, which by the way, caused 12 million people to stop taking fish oil supplements.
7. Scientific sloppiness
Lots of ways to screw up scientific research, but here are some very common ones seen in Omega-3 studies:
- Treatment duration is too short. This is often the case with studies that look at DHA’s effect on brain health.
- Poorly defined end points. In earlier Omega-3 studies, death of patient was often the study end point. In all of the recent recent studies, ‘non-fatal events‘ became the study end point due to, well, people not dying. Some called it quits early because people were not dying as expected. Those stubborn patients…how dare they!
- Too few subjects. This causes ‘insufficient power’ for the number crunching to yield results. This does not mean that fish oil did not work, but rather a failure to detect a benefit due to too few people/subjects.
- How Omega-3 is measured. Omega-3 levels is plasma tends to rise and fall depending on your last meal. The level of Omega-3 incorporated into your red blood cells membrane may be more reliable. The least reliable is asking people what they ate the previous day (food frequency questionnaires) and extrapolating that into a conclusion.
- Lousy placebo. What makes a good placebo against fish oil? Vegetable oil? Margarine? Olive oil? Nope, nope and nope. Yet, studies use these regularly.
- Confusing primary and secondary prevention. I’ll excuse the media for not getting this, but not scientists.
- Primary prevention is preventing a disease before you get it.
- Secondary is treating it after you get the disease. Example: may be fish oil or eating fish won’t do a damn thing for Alzheimer’s after you get it…but, may be, watching you diet and eating fish in your youth and middle age helps. You’d need a 50-year study to prove this (see point 1).
Here is a link to A Rough Guide to Spotting Bad Science.
Omega-3 is not magic. It is entirely possible that even massive amounts of Omega-3 will not reverse advanced Alzheimer’s. We just don’t know. But I do know that giving fish oil to Alzheimer’s patients for a few months and expressing outrage at the lack of results isn’t accomplishing much.
For a more technical review of some of these points, see Dr. Harry Rice’s lecture here.
A special case of sloppiness…
This recent study in the Annals of Internal Medicine (a prestigious journal), despite its Cambridge/Harvard authors, simply screwed up. But the authors issued a reluctant correction, possibly due to pressure from other scientists.
The original version of the study (that the media frenzied on) said that fish oil did not work. An ‘Oops! Never-mind-us-but-fish-oil-does-work’ version came a couple of weeks later. The correction, of course, was ignored by the press.
Ignoring the obvious
Omega-3 EPA and DHA are essential nutrients. Let’s not forget that.
It doesn’t matter what the TV says. You still need Omega-3 to stay alive. And hopefully you get it from fresh fish rather than supplements or plants.
*Individual results may vary. These statements have not been evaluated by the Food and Drug Administration.