Lately it seems you can’t read or watch the news without coming across an attack on fish oil.
Unfortunately, many media are letting sensationalism trump their responsibility to get all the facts. But the bigger onus falls on researchers who ignore (or perhaps are ignorant of) critical errors and limitations in their study design and overstate the importance of their results.
Whatever the reason, the effect is the same: millions of people now questioning whether their fish oil supplements are worth taking.
As a biochemist and medical researcher with more than 30 years devoted to the study of inflammation and the protective anti-inflammatory benefits of omega-3s, let me take a moment to respond to those who seem bent on turning you away from this critically important nutrient.
A Rich and Impressive Backstory
If you search for studies on omega-3s in the scientific database PubMed, you’ll find over 20,000 papers published on the subject in just the past 20 years, with nearly 1,700 of them published in 2014 alone. It’s safe to say there has never been a more studied medicinal natural product than the omega-3s found in fish oil, starting in the early 1970s with studies on Eskimos in Greenland who had a low incidence of heart attack and stroke. Rather than fizzling out, as investigations do when their results are disappointing, the topic of omega-3s is hotter than ever.
So when the press decides to write about one study, particularly one whose authors infer that their results carry the same or greater weight as the thousands of studies that precede them, both the researchers and the journalists should expect some scrutiny.
There are many reasons for a study to pop up once in a while that has a different result than found by prior research. But the first reaction of the researchers and the press should be caution, not a rush to potentially mislead the public about something that could be very important to their health.
There is no such thing as a “perfect” study, but when it’s well designed, when it stands up to rigorous statistical analysis, and when it is validated again and again by other researchers repeating the study and getting the same results, it begins to carry more weight. Such is the impressive backstory of omega-3 research. It is not easily discounted.
Proper Study Design
A well-designed study tries, first, to winnow down an area of exploration to a specific question (hypothesis) that can be tested. It tries to eliminate, or at least account for, as many variables as possible. (Variables are factors that can create confusion, like the old joke about the person who orders a rum and cola, then blames the cola for his drunkenness.) It takes into account the results of prior studies. It should be based on known facts about the subject, such as the effective dose of a particular drug or natural product to be used in the study. Additionally, it should be repeatable, down to the smallest detail, so other researchers can see if their results agree (implying that humility is part of good design, too). When even one of these elements is weak, the entire study weakens. Perhaps the most critical portion of any research paper other than the results are where investigators state the limitations of their research. Believe me, after reviewing scientific papers for more than 30 years, I can tell you that all studies have important limitations.
Speaking of not stating limitations…that is how I feel about the latest attack on fish oil. In this study, the authors concluded that there was no benefit of omega-3 supplements for stopping cognitive decline. Newsweek published the scoop with the sensational headline, “Omega-3 Supplements Are a Waste of Money.” Neither properly acknowledged that the results were swimming upstream against several important prior studies that disagree.
Perhaps more importantly, the press seemed unaware that the supplemental omega-3 fatty acid given in the study was under-dosed by more than half. Now this critically important limitation was in the buried in the paper, but someone in the press forgot to mention it. In fact, the study used a low dose of the omega-3 DHA, even though every other paper in the scientific literature that showed positive results suggested a higher dose was needed.
The new omega-3 issue is the now much-repeated and well-validated discovery that there is tremendous genetic variation in our ability to make long-chain omega-3s DHA and EPA from essential fatty acids found in non-fish, plant sources (nuts and leafy vegetables).
Over the past five years, this genetic issue has become one of the hottest topics in omega-3 research and is a prime example of a brave new world of individualized nutrition. Based in large part on our ancestry, some of us are walking around with bloodstreams virtually brimming with DHA and EPA and enjoying the health benefits. At the same time, some of us have levels so low that we might actually have an omega-3 deficiency, especially in the midst of all the competing omega-6s found in the modern western diet.
Now imagine the confusion that this has the capacity to create if this information is not considered in clinical studies testing the effectiveness of fish oil. Those in the study who are rich in omega-3s because of their genetic makeup clearly will not be impacted by fish oil supplements because they already have plenty. Those who make little from the plant-based omega-3s in their food supply will respond to varying degrees to fish oil supplements, depending on their genetic capacity to make it.
Any clinical study that lumps everybody together without considering how much of the beneficial long chain omega-3s like EPA and DHA that individuals can naturally make will likely get hijacked by the fact that the study design failed to control this powerful variable. Consequently, the statistics are not strong enough to detect effectiveness.
I believe not taking genetic factors into consideration is a major reason many clinical trials are failing. Rather than a scoop that reveals a failure of fish oil, perhaps the scoop should be a poor study design, or inappropriately stating study limitations, or less than stellar journalism.
The Bottom Line
So, should we supplement our diet with fish oil or not? Based on strong scientific evidence, my opinion is yes. Here’s why.
In the first year of their lives, the main food source for most baby fish is a plant-based omega-3 called ALA, which is abundant in algae. Fish are factories in the way they convert that ALA into beneficial DHA and EPA. Larger fish that are vegetarian species continue eating (and converting) that same vegetarian diet. Larger fish that are carnivores or omnivores eat those smaller fish. Because fish specialize in converting ALA into DHA and EPA, fish and fish oil are sure sources of DHA and EPA for us humans, whether we have the gene variants to make DHA and EPA ourselves or not.
If it turns out you are one of those people blessed with the genes to convert the ALA from, say, walnuts or salads into DHA and EPA, fish oil may not help you as much (because you don’t need much help). But it won’t hurt you and I still believe it is important for these folks to balance their omega-6 to omega-3 ratio. If it turns out that you’re not so blessed in that area, you likely are among the people who will most benefit from fish oil, and your benefits might be moderate or they might be huge, depending which versions of the genes you have.
In summary, we now have credible evidence that there are gene-diet interactions affecting omega-3 biosynthesis in the human body. And these interactions, together with the modern western diet, lead to individuals who can have lots of omega-3s in their body, and individuals who make almost none. Evidence indicates that low levels of omega-3s are associated with a marked increase in the risk of cardiovascular disease as well as a range of other diseases that, in many cases, have reached epidemic levels over the past 50 years.
So a critical question that scientists and reporters alike must ask themselves when they are tempted to overstate what the science actually says is: Might what I say do harm?
When there are headlines like “Omega-3 Supplements Are a Waste of Money”—and at the same time millions of people have an omega-3 deficiency as a result of the modern western diet and their genetics, then great harm has been done. More importantly, when these same people stop taking their fish oil and their health suffers because of these headlines, then even worse harm has been done.
Additionally, poor study design, unwarranted conclusions, and sensational mainstream media headlines lead not only to adults rejecting fish oil supplementation for themselves, but tragically also for their children, who need long-chain omega-3 fatty acids (especially DHA) for normal brain development and mental health. I implore scientists and reporters to be very careful in this incredibly sensitive area when they communicate their scientific results to the public.
As a scientist who has been working in this area for more than 30 years and has published over 130 scientific articles, fish oil has the potential to have far too many benefits to let a few highly publicized “negative” studies sway you. I take fish oil every day and eat omega-3 rich fish like salmon at least every other day, with confidence. For me, the positive evidence far outweighs any negative reports.