July 15, 2013

Omega-3 Oils Cause Prostate Cancer?...Something's Fishy

[updated July 31st, 2013]

Here's a link to Mercola's article entitled "Absurd Study Claims Omega-3 Fats Raise Prostate Cancer Risk".


[updated July 17th, 2013]

Customers have been coming in this week asking about our opinion regarding the latest study that identified a significant increase in prostate cancer for men with high DHA blood serum levels.  Here's the snippet from the media...

SEATTLE – The largest study ever to examine the association of dietary fats and prostate cancer risk has found what's good for the heart may not be good for the prostate.

Analyzing data from a nationwide study involving more than 3,400 men, researchers at Fred Hutchinson Cancer Research Center found that men with the highest blood percentages of docosahexaenoic acid, or DHA, an inflammation-lowering omega-3 fatty acid commonly found in fatty fish, have two-and-a-half-times the risk of developing aggressive, high-grade prostate cancer compared to men with the lowest DHA levels.


The media actually made a liberal interpretation of the research and reported that fish oil caused prostate cancer which is not strictly true.  However, we're always interested in new research and try to keep an open mind.  Here's what we've uncovered so far...

The key results, which the authors of the study spoke of with extreme surprise because the results shown were the exact opposite of the huge amount of data supporting the benefits of fish oil and DHA, are listed below:

  • Men with the highest levels of DHA were 2.5 times more likely to get an aggressive form of prostate cancer.
  • Men with the highest levels of trans fat (bad fat) were the least likely to get an aggressive prostate cancer.

Strange, huh?

Past research has shown that DHA could be beneficial in preventing prostate cancer.  A Swedish study of 6000 men showed that those that ate fish were less likely to get cancer than those that ate less fish.  Another study from New Zealand found a 38% decrease in risk markers related to prostate cancer in those men with higher DHA levels. Other studies in Japan and Brazil found similar results.

Another problem with this new finding is that scientists cannot figure out how DHA could promote rapid tumor growth or how trans fats could reduce tumor growth.  Usually there is a plausible theory on how a particular food component can affect a disease...not in this case.

A more in-depth study pokes some holes into the research.  As is true with many of these types of studies, they try to isolate a particular relationship between a nutrient component and a disease in a too simple approach.

For example, do high levels of DHA in blood equate to eating more omega-3 rich foods or supplementing large amounts of fish oil.  The answer is no.  While high levels of DHA intake and increase your blood serum levels, a low fat diet can also increase your DHA blood levels.  So it is possible that a low fat diet (possibly high in sugar and unhealthy carbs) could be the culprit in promoting aggressive tumor growth.  It was noted in the study that these men were not supplementing.  So we can't assume that DHA intake is the culprit without more study.

The actual purpose of the study was to determine the effectiveness of the drug finasteride (Propecia, Proscar).  It is possible that the drug interacts with omega-3 oil in an unexpected way.  We have seen this happen with prescription drugs and otherwise benign nutritional elements such as magnesium.

I could go on and on but to summarize, there are a ton of holes in this study to the point that it's only use is to scare people away from a supplement that has a huge amount of science behind it touting its benefits to heart and brain health.

What's a man to do?

Two things....

First, do your own research and decide for yourself.  If you feel you are at high risk or have a family history of prostate cancer, reduce or eliminate omega-3 supplementation from your diet.  There may be other supplements that can help you reach your goals besides fish oil.

Finally, a contributor to Mark's Apple summarized the "big truth" behind the debate:  

"Even though this study doesn’t give any reason to shun fatty fish or their oils, it’s a nice segue into a related issue: A bad diet plus fish oil is still a bad diet."

Eat and live healthy and supplement for optimum health.


If you want to read more, here's some links:

Mark's Daily Apple

The following blog had a good discussion between regular folks trying to sort out the study.



For us, our opinion is that this is incomplete and/or junk science and we will continue forward as usual.  I will update this blog and we learn more.


[Updated July 17th, 2013]

Here is an additional link to an article digging deeper into the flaws of this research:

Badly Flawed Study of Fish Oils Leaps to Wildly Unsupported Conclusions...Alliance for Natural Health