24 Jul The Fish Oil Cancer Connection
Major media outlets have recently taken a hold of a study citing a connection between fish oil and increased risk of prostate cancer in men.
- Omega-3 supplements linked to prostate cancer? (Fox News)
- Hold the salmon: Omega-3 fatty acids linked to higher risk of cancer? (CNN)
- Omega-3 supplements may trigger prostate cancer? (Nursing Times)
The list goes on and on.
To the casual viewer, these reputable sources most likely gave this study a thorough once over and examined it for its merits and dissected its flaws. One would then assume that the study likely gave one group a placebo and the other fish oil and that one got more cancer, right?
We will get to my thoughts and assessment momentarily, but the inference from this study) is that fish oil can cause cancer.
Tag lines like that sell advertising get you viewers.
Here’s what is really going on.
Let’s get the major point out of the way first: NO NUTRITIONAL SUPPLEMENTS WERE USED IN THIS STUDY.
None. Not one fish oil pill, no teaspoons of fish oil, not even some sort of crazy suppository, not even fish dinners. Nada.
Well, Brad, how did they come to this conclusion then?
The study measured the blood of 800 men; over the course of the study, some of them developed prostate cancer. The authors of this study were surprised at the fact that higher levels of Omega-3 fatty acids in the blood, specifically DHA, were higher in the men with prostate cancer than without.
To the untrained eye, this seems plausible link. Higher DHA, more cancer. However, we must remember that correlation does not equal causation.
First off, there are three main types of Omega-3’s: ALA, EPA, and DHA.
The levels of the fatty acid of interest in this study were DHA, and those were measured as a percentage value. This is an important fact. In our blood, the levels of all our phospholipids (Omega-3’s, -6’s, etc.) will total 100% (everyone remembers that part of math, right?) This study noted that the percentage of DHA were high.
This info could stem from a lower percentage of something that the study’s authors weren?t calculating seeing as they only looked for 8 of the several hundred fatty acids. Being a percentage, if one is lower, another has to be higher. (there’s that 100% again)
Furthermore, we know that consuming large quantities of Omega-3’s causes DHA levels to rise, as often seen in a low fat diet. Don’t you know how fat makes you fat! You should totally, like, avoid it? duh. This low fat bread will keep you lean and healthy. But I digress.
There were some more interesting things in this study that didn’t make the mainstream news.
As world renowned nutritionist Dr . Jonny Bowden points out, “Participants who had the highest levels of Trans fats in their blood also had the least risk for prostate cancer.”
Didn’t see that headline, “Trans fats prevent cancer!”
Nor will you. Nor will you hear doctors saying don’t eat fish.
Furthermore, there were a host of variables that were accounted for in the jump to fish oil giving men prostate cancer.
-53% of the subjects with prostate cancer were smokers
-64% of the cancer subjects regularly consumed alcohol
-30% of the cancer subjects had a first degree relative with prostate cancer
And last but certainly not least…80% of the cancer subjects were overweight.
Clearly there is a lot more than fish oil at work here.
The bottom line with this study is that it was observational. There were no supplements given out to participants, there were a select few fatty acids accounted for, and only counted as a percentage.
Studies you should know about are more like this one from the Harvard School of Public Health.
Over the course of 11 years, Omega-3 fats were measured in 2,692 adults. Those with the highest levels were 27% less likely to die over the course of the study than those with the lowest levels.
That doesn’t mean if a little is good, more must be better. There is an optimum level, but that is still being accurately determined.
Finally, my point: it’s not time to jump off the fish oil bandwagon. I’m still going to take it and recommend it to my clients. Its positive effects far outweigh any perceived negatives portrayed in mass media. (those guys are always objective and aren’t out to make money off of us at all?)
And as for fish oil giving men prostate cancer, that’s a whopper of a fish tale.
For more information on fish oil check these articles out: