What you REALLY need to know about fish, omega-3s, and prostate cancer risk

Science caught “sleeping with the fishes”

Many men—including some of my own doctor friends—have been asking me about the latest “fish story” making headlines. In July, researchers from the esteemed Fred Hutchinson Cancer Research Center in Seattle announced that they had found a “statistical link” between fish oil and prostate cancer.1

The news was trumpeted from the rooftops. Every major media outlet covered it. Unfortunately, the results of this study are misleading at best. And downright dangerous at worst.

Sadly, I’m not surprised, considering the source.

Over the last three decades, this Center happily received billions of dollars of 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. So I also wasn’t surprised to find this particular study was filled with flaws.

To help get the story straight, in this issue of Insiders’ Cures, I’ll cover all the bases regarding this particular prostate cancer scare. I’ll also go over the ins and outs of fish oil and omega-3’s—what goes into a quality supplement, and other sources of these essential fatty acids. And while I’m at it, this is the perfect opportunity to discuss prostate health in general. So later in this issue, I’ll also share those details—and tell you about my role in discovering the single most important nutrient for prostate health.

But first, back to the latest nonsense about fish oil and prostate cancer. Let’s fill in the “fishin’ holes” these scientists left in their so-called research, one by one.

Aimless “fishing” expedition ends in a “maritime disaster”

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. A “perfect storm” for getting specious results. Apparently, they just stumbled across this “statistical association” without having any understanding of what could have caused it, or whether it was even real.

And this leads to the next hole in their findings…

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 if they just ate a lot of fish, rich in omega-3 fatty acids.

And that’s a key point.

What real science says about fish consumption

If the men ate fish, how do the researchers know for sure it wasn’t something else in the fish—such as mercury—that caused the statistical bump in cancer rates?

The answer is: They don’t.

And to suggest otherwise blatantly disregards all the prior existing science.

In fact, just three years ago, this very same group of researchers reported that consumption of fish is not associated with any increased risk for prostate cancer.

And in 2010, a group of Canadian researchers conducted a meta-analysis (looking at all studies that had been done to date). The results indicated a reduction in aggressive, late stage, and fatal cancers among cohort studies.2

These are the best kind of statistical studies, since initially healthy people are followed over time to determine who eventually develops the disease outcome.

And there was no overall relationship between prostate cancer and fish intake.

But here’s (another) important point missed by these researchers—and all the “experts” who have been discussing this study—both pro and con: Prostate cancer becomes very common as men get older. In fact, the majority of men over age 75 will actually have prostate “cancer.” However, most of the time, this is a “silent” cancer that is so slow-growing and benign it rarely causes any problems.

So, what you should really be concerned about are the aggressive “late stage” and “fatal” prostate cancers. The kind these same researchers found are reduced by fish consumption.

But setting aside all this double-talk from Seattle, the bottom line is—other studies have also found higher fish intake to be associated with lower prostate cancer incidence, and fewer deaths from prostate cancer.

And consider prostate cancer rates in Japan, which are much lower than those in the U.S. The Japanese eat eight times more fish, on average, than Americans. If there were any real problem with fish it would be obvious in this kind of comparison.

On the other hand, if the men in this new study had high levels of omega-3s because they took fish oil supplements (vs. high consumption of fish), that’s a whole different set of questions…

What you don’t know about your fish oil supplement CAN hurt you

Another “fishy” thing about the new Seattle study is that the omega-3 levels (EPA + DHA) were well below those typically seen in people who are actually taking fish oil supplements (as documented in well-done studies such as the Framingham Heart Study).

But, just for argument’s sake, let’s say the men in this new study were taking fish oil supplements…

The prostate cancer association noted by these researchers could simply mean 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 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 or other heavy metals. These can also act as carcinogens.

Specificity matters

Lastly, the researchers did not distinguish between different 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 lot of ALA in their blood—which 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.

Even worse, however, is how these researchers appeared to knowingly mislead readers. 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 grade school science class.)

But these researchers only cited 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.

So, to that end, let’s move on and discuss what to look for in a fish oil supplement.

Quality control

As I mentioned above, it is important that crude fish oils are distilled under nitrogen (which is chemically non-reactive). This process protects the delicate and easily damaged active forms of EPA and DHA from becoming oxidized and rancid.

Distillation also removes mercury, volatile organic compounds, and solvent residues that are present in the crude fish oil. (It also preserves fresh taste, which I’m sure you’ll agree is critical when it comes to any fish products.)

Aside from being distilled, any fish oil supplement you choose should be in capsules (not tablets or pills)—and preferably softgels.

Post production testing should be done by a reputable independent lab. This ensures that the delicate active ingredients (DHA and EPA) have not been harmed during processing and remain in their most healthy and beneficial form.

Of course, it’s impossible to know whether the brands of fish oil lining the shelves in your local pharmacy live up to these standards. (And don’t look for the average pharmacist to know, either.) So I’ve tracked down a source that does—a company called PERQUE. They offer two high-quality fish oil formulas: EPA/DHA Guard and Triple EFA Guard. To learn more about PERQUE fish oil supplements go to www.vitamins-today.com or call (800)525-7372. I use PERQUE for myself and my family.

Nordic Naturals also makes several great fish oil products that I have personally tested in years past.

Assuming you choose a high-quality brand, I recommend 1 to 2 grams of DHA/EPA from fish oil per day.


1. “Plasma Phospholipid Fatty Acids and Prostate Cancer Risk in the SELECT Trial.” J Natl Cancer Inst. 2013; 105(15): 1,132-1,141

2. Fish consumption and prostate cancer risk: a review and meta-analysis. Am J Clin Nutr. 2010; 92(5): 1,223-1,233