Something smells fishy–and it’s not the fish

Over the last decade, the mainstream media largely ignored hundreds of solid studies that underscore the positive health benefits of fish oil. And most of this good, solid research passed into oblivion with barely any attention from the mainstream.

But let one flawed (and frankly, just plain “fishy”) study turn up a negative statistical “association,” and the mainstream media is ready to call out the National Guard. Or, perhaps the Coast Guard.

That’s just what happened recently when researchers found a “statistical link” between fish oil and prostate cancer. Researchers at the esteemed Fred Hutchinson Cancer Research Center in Seattle conducted this study.

Now, I made more than one trip out there during the 1980s and 1990s. And they even offered me a senior scientific position at one point.

But the sun came out just one day during all my visits. And I was concerned about vitamin D even back then.

Plus, it seemed to me that the diet and cancer program at this hard-core, high-tech, and mainstream cancer center was just “window-dressing.” They used it to capture new government research funds. In fact, over the last three decades, this Center happily received what amounts to billions of dollars in research grants from the National Cancer Institute to study diet and cancer.

But they put these funds into the hands of scientists who didn’t seem to have any genuine interest or expertise in nutrition or natural approaches.

And boy, did that turn out to be the correct perception (even through the perpetual Seattle rain and fog).

Truth be told, I wasn’t surprised when I found the Center’s new study linking fish oil with prostate cancer risk was filled with flaws.

First of all, when you design a scientific study, you are supposed to make a hypothesis or a prediction at the outset. This is grade school science class stuff, right? But for this study, the Center’s researchers went on a “fishing” expedition–literally, as well as figuratively.

They had no hypothesis. No theory. And they weren’t even testing a possible biological “mechanism” to see if fish oil could possibly cause prostate cancer. None of that. Apparently, they just stumbled across this “statistical association” without having any understanding of what could have caused it. They were clueless, but still happy to trumpet their results.

And this leads to my next point…

Yes, the researchers found that some men with prostate cancer had really high levels of omega-3s. And, yes, you find these fatty acids in fish and fish oil supplements. But the researchers couldn’t tell whether the men with high omega-3s took fish oil supplements. Or just ate a lot of fish, which are rich in omega-3 fatty acids.

And that’s a key point.

If the men ate fish, how do the researchers know for sure it wasn’t something else in the fish–such as mercury or other toxins–that caused the statistical bump in cancer rates? And not the fish oil?

The answer is: they don’t.

And any scientist would never just assume it was the fish oil causing the cancer.

On the other hand, if the men had high levels of omega-3s because they took fish oil supplements, that’s a whole different set of questions.

And it would probably mean, given the weight of all the other evidence, that these men took poor-quality fish oil supplements.

You see, when it comes to fish oil, there is a big difference between properly distilled fish oils and crude fish oils.

Fish oils that are not properly distilled can contain oxidized omega-3 fatty acids, which are known, like any oxidant, to be harmful. And even cause cancer. Remember, any “anti-oxidant” can become oxidized and harm cells under the wrong circumstances.

Beyond that, without proper quality control procedures, fish oils can contain contaminants such as arsenic, lead, mercury and other heavy metals. These are also harmful and may potentially act as carcinogens.

Lastly, the researchers did not distinguish between forms of omega-3s. For example, ALA is the inactive precursor of omega-3 fatty acids. EPA and DHA are the active forms.

Healthy men (and women) convert inactive ALA into active EPA. But men who are not well, convert ALA poorly, or not at all. And the Center’s researchers did not specify which kind of omega-3s they found in their subjects’ blood. For all we know, these men could have had a ton of ALA in their blood. This would indicate they were not well in the first place.

In the end, we cannot and should not draw any valid conclusions from this flawed study. This study proved nothing…except how clueless cancer researchers still are about nutrition.

What is even worse, however, is that these researchers appeared to mislead readers knowingly. You see, a scientist should point out both sides of an issue. You should always cite studies that both support and refute your conclusion. (Again, you’ll probably remember this from your fourth-grade science class.)

But these researchers only cited the few, selected studies that support their own incorrect conclusions. And they ignored mounds of published studies that don’t support their conclusions.

The sad truth is, without knowing the quality of the supplements you take, or study, you don’t know what you are getting. And what you don’t know can hurt you.

I recommend at least 1 or 2 grams of fish oil per day. Nordic Naturals makes several great fish oil products.


1. “Plasma Phospholipid Fatty Acids and Prostate Cancer Risk in the SELECT Trial,” Journal of the National Cancer Institute ( first published online: July 10, 2013