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Something is Fishy about Omega 3′s causing aggressive Prostate Cancer

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I heard about this this study from a news wire late yesterday evening and already received about a dozen emails from patients, friends and colleagues on the latest news suggesting that omega-3 fatty acids increases the risk of prostate cancer – including aggressive prostate cancer.

HERE is the link to the abstract of the study

Details of the study:

  • Brasky et al. looked at collected data and specimens from the SELECT trial which showed in a study that those men who consumed synthetic form of vitamin E had a 17% chance of developing prostate cancer – More on the SELECT trial and synthetic vitamin E HERE
  • The findings indicate that high concentrations of EPA, DPA and DHA — the three anti-inflammatory and metabolically related fatty acids derived from fatty fish and fish-oil supplements — are associated with a 71 percent increased risk of high-grade prostate cancer.
  • The study also found a 44 percent increase in the risk of low-grade prostate cancer and an overall 43 percent increase in risk for all prostate cancers. (Brasky et al. 2013)
  • What’s even more interesting is that Omega 6 fatty acids were associated with lower risks of total prostate cancer(Brasky et al. 2013)

Interestingly, this same study group published a paper in 2011 showing Docosahexaenoic acid (DHA) was positively associated with high-grade prostate cancer but trans-fatty acids found in participants blood showed a DECREASE risk of aggressive prostate cancer.(Brasky et al. 2011)

That’s right, the same trans fatty acids from margarine and cooked oils that contribute to heart disease. Yes, the same type of fat that is banned from New York restaurants.

Omega 6 fatty acids has shown to have an adverse effect if taken in excess and has been implicated in the development of several cancers including prostate (Berquin et al. 2007). Omega 6 fatty acids (namely arachidonic acid) is converted by CycloOxygenase -2 enzyme into prostaglandin E2, a pro-inflammatory molecule implicated in the development of numerous cancers (Wang et al. 2007)
Imbalanced Omega 6: Omega 3 ratios (higher Omega 6) have shown to increase the risk of prostate cancer (Leitzmann et al. 2004)

Take home message from both Brasky studies: Eat more trans fatty and omega – 6 fatty acids and men will prevent aggressive prostate cancer.  I don’t know about this. This smell too…well,  fishy.

My take on this (thus far)

One must be very careful with making decisions based on the latest news bytes and headlines. We, as a society, have a tendency to make decisions based on the last study or news advertised, rather than the combination of studies published on a specific topic.

The last study is not necessarily the best study.

In addition, studies should be read critically – there are inherent flaws in most of them.

The findings from Brasky et al. 2013 seem to be a retrospective study (looking back in time) and does NOT show cause and effect.

Studies that are prospective in design rank higher in importance of evidence and are more useful and suggestive in our decision making on what to consume to improve our health.

Are there prospective studies showing protective benefits of omega 3 fatty acids against prostate cancer?

Yup.

Researchers investigated the effect of dietary fish intake amongst 6272 Swedish men who were followed-up for 30 years. That study reported that men who ate no fish had a two–three-fold increase in the risk of developing prostate cancer compared with those who consumed large amounts of fish in their diet. (Terry et al. 2001)
Another prospective cohort study based on the Physician’s Health Study found that fish consumption (≥5 times per week) was not related to prostate cancer risk but was protective of prostate cancer–specific death.(Chavarro et al. 2008)
Other studies have suggested lower prostate cancer risk with Omega 3 fatty acids from fish in Swedish men (Norrish AE, et al.) and in Japanese and Brazilian men (Kobayashi et al. 1999).

A large prospective cohort established in 1986 looked at 51,529 American men, 40 – 75 years of age, completed a mailed questionnaire about demographic and medical information found that a high intake of fish was associated with a lower risk of metastatic prostate cancer. A similar association was also found for dietary marine fatty acids from food.

An important clinical study published by a group at the Harvard School of Public Health examined the link between dietary fish consumption and the risk of metastatic prostate cancer. This paper reported results from the Health Professionals Follow-up Study that involved 47,882 men over twelve years. During the twelve years, 2,483 cases of prostate cancer were identified. Of these, 617 were advanced and 278 were metastatic. Eating fish more than three times a week reduced the risk of prostate cancer but had an even greater impact on the risk of metastatic prostate cancer. For each additional 500 mg of marine fat consumed, the risk of metastatic disease decreased by 24%! (Augustsson, et al. 2003).

In a meta-analysis (a study of studies) Szymanski and his team found that a significant 63% reduction in prostate cancer-specific mortality in those that consumed fish but no link between eating lots of fish and men’s risk of developing prostate cancer. (Szymanski et al. 2010).

Am I getting carried away with all these citations yet?

I know the content became scientifically heavy but I just wanted to make a point that there are reason’s why many practitioners like myself recommend fish and fish oils to patients.

Final note and Doggy Bag

Most men will develop prostate cancer within time regardless of what they eat or don’t eat. If you live long enough, you’ll get it. The deadly kind is what we are trying to avoid.

The 71% aggressive prostate cancer associated with Omega 3 fatty acid consumption sounds dubious.

The fish oils from fish or supplements in the study did not control for the quality of fish or fish oil. Some fish (and fish oil supplements) can contain environmental chemicals that can contribute to prostate cancer such as PCB (Ritche et al. 2005). Also, fish oils can oxidize easily if not careful which may make them more damaging. This was not accounted for in this study.

Personally, I am not ready to ignore the plethora of research suggesting its beneficial effects.

I just popped 3 fish oils a minute ago. I am not making any personal changes on my fish oil consumption based on a blood test of Omega 3 fatty acids from a retrospective study. In my opinion, this study is informative, mildly suggestive, but weak.

I do recommend for readers to be properly monitored by a nutritionally oriented physician when making dietary choices. There are individual nuances where, indeed, a nutrient can potentially make health matters worse.

Lastly, (whew!) another shortcoming of both Brasky studies is that we do not know the diet of the studied subjects.

The consumption of fish or fish oil supplements with crappy food does not make the crappy food less crappy. Another words, a poor diet with fish or fish oils will not protect men from prostate cancer.

This is a hot topic, so chime in if you’d like.

References:

Berquin IM, Min Y, Wu R et al. Modulation of prostate cancer genetic risk by omega-3 and omega-6 fatty acids. J Clin Invest 2007; 117: 1866–75
Wang MT, Honn KV, Nie D. Cyclooxygenases, prostanoids, and tumor progression. Cancer Metastasis Rev 2007; 26: 525–34

Terry P, Lichtenstein P, Feychting M, Ahlbom A, Wolk A. Fatty fish consumption and risk of prostate cancer. Lancet 2001; 357: 1764–6

Chavarro JE et al. A 22-y prospective study of fish intake in relation to prostate cancer incidence and mortality. Am J Clin Nutr 2008; 88: 1297–303.

Augustsson, K., et al., A prospective study of intake of fish and marine fatty acids and prostate cancer. Cancer Epidemiol Biomarkers Prev, 12(1): p. 64-7, 2003.

Szymanski KM, Wheeler DC, Mucci LA. Fish consumption and prostate cancer risk: a review and meta-analysis. Am J Clin Nutr. 2010 Nov;92(5):1223-33.

Leitzmann MF, Stampfer MJ, Michaud DS, et al. Dietary intake of n-3 and n-6 fatty acids and the risk of prostate cancer. Am J Clin Nutr. 2004 Jul;80(1):204-16.

Ritchie JM, Vial SL, Fuortes LJ, Robertson LW, Guo H, Reedy VE, Smith EM.Comparison of proposed frameworks for grouping polychlorinated biphenyl congener data applied to a case-control pilot study of prostate cancer. Environ Res. 2005 May;98(1):104-13.

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by Dr. Geo

35 comments… add one

  • Nice post. Quick comment: Researchers are always searching for data sets to use, and in light of the time and cost associated generating original data, they frequently opt to tap into an existing data set. Although expedient and cost effective, doing so frequently places their analyses at high risk due to poor fit and potential flaws in data itself. In other words, compromise leads to compromised results, also known as GIGO (garbage in, garbage out). I would like to see a moratorium on any use of data sets that are objectively flawed (like SELECT). Also, like you, I would like to see a moratorium on sensationalized media headlines that misinterpret and therefore mislead. The media are doing a disservice to both doctors and all people trying to find solutions to health concerns. You wrote a nice post on this very subject a while back that your readers may be interested in (http://www.xywellness.com/blog/vitamin-e-and-prostate-cancer). Thanks again for the interesting post. Great work. DG

    Reply
  • Vero ,

    Great post! I’d love to know who finances this research. Thanks, Dr. Geo, for reacting so quickly!

    Reply
  • Will Johnson ,

    Excellent fact based rebuttal! Having just heard this ‘news’ on GMA, my initial reaction was “Now what?!” and immediately ran to my computer for further feedback. Clearly, this news bite will ultimately cause much handwringing with it’s lack of clarity and I certainly agree with both you and David G. in championing proper controls over media based shooting from the hip. Thank you for a rational and quick response to this. Waking up to the sound of sunshine is much preferable to waking up to the sound of thunder and lightening!

    Reply
  • Thanks for your comment Will. I am concerned that people who have benefited from Fish oil consumption will now discontinue based on sensationalized media attention rather than basing it on the full scientific spectrum.

    Reply
  • Glenn Wood ,

    Thanks for the great post, love your last line – “The consumption of fish or fish oil supplements with crappy food does not make the crappy food less crappy. Another words, a poor diet with fish or fish oils will not protect men from prostate cancer.”

    Always remembering we are all individuals with different genetic and environmental make-ups so nothing is going to be all encompassing for each man. If you take fish or krill oil, and you feel okay, I say keep it up.

    Reply
  • Dr. Geo,
    Thank you for your thoughtful and informed comments!
    As you say, some individuals will discontinue fish oil supplements because of this “study”. Fortunately, more and more individuals have made connections with rational, not-bought-off sources of information like you provide. I know that my patients will contact me and ask my opinion before following a study such as this.
    I found a link to your blog in a discussion on the FB page of The Personalized Lifestyle Medicine Institute – https://www.facebook.com/PersonalizedLifestyleMedicineInstitute

    Reply
  • Mike ,

    If one must, eat a can of sardines once in a while, (there are studies that omega 3′s in salmon isn’t all what it’s cranked up to be–and forget farmed salmon, almost negligible amounts)
    cut out oils from ones diet, (forget evoo–tastes great,much research shows no health benefits–yeah i know, the paleo-etc. diets–forget meats, poultry, eat a “little” fish if one must as “much” research shows too much protein (igf-1)
    is definitely not favorable–cut out the junk. If one eats clean their supplement intake may be able to be reduced/eliminated–taking supps is like playing russian roulette as one has no idea what crap they are taking–except for Dr. Geo’s quality supp.–most is just marketing voodoo.

    Reply
  • Wayne Adriance ,

    One possible confounding influence in this study derived from the Select study of vitamin E & selenium is the role of selenium cited in a 2009 (June 27) Dana-Farber Cancer Institute study in both increasing risk of advanced prostate cancer or decreasing risk depending on genotype. Do men supplementing with extra fish oil also supplement with extra selenium? Also do men with increased fish oil supplementation self-medicate to a greater extent because they are at increased risk of cancer? Do they have a family history of cancer, or a history of increased inflammation? If you found an increased level of nitroglycerin in a heart condition cohort, would you proclaim that nitroglycerin caused heart disease?

    Reply
  • Eden ,

    I haven’t read the published article yet, but will do so soon. As an epidemiologist, working with a cancer registry, I have reservations about this recent work. Many questions arise which seem not to have been addressed – certainly not reported in the media coverage. Firstly, the blood samples of the patients were all taken at one point in time, indicating that the levels of omega 3 were as they were merely at that cross-sectional time. There is no report of these levels having been high, or low, over a length of time (years?) which, if there is any genuine cause and effect, would probably be needed. Secondly, there seems to be no (reported) exploration of the level of plasma omega3 in relation to dietary and supplemental consumption. I look forward to reading the actual article.

    Reply
  • Thank you for taking the time to share your expert opinion with us Eden. There are multiple inconclusive points with this study. It brings more confusion and frustration than solutions.

    Reply
  • Chris ,

    Thank you for this factual breakdown and countepoints. I take Omega 3′s for my “Trigs.” I hate to admit but I was panicking about this at first but I feel much more at ease now. I am with you, I am not going to stop taking my supplements. Thank you, Dr. Geo!

    Reply
  • Thanks Chris. Let me know how you do.

    Reply
  • Sid Whitkin ,

    Dear Dr. Espinosa,

    Thanks for your in depth response, and bringing light to the subject which has started to become controversial and spread doubt in some places. However, I did read an article some time ago by Dr. Robert Rowen, (a noted alternative physician), who was very emphatic about his position against fish oil; apparently backed up by considerable scientific research. Perhaps you can look into this and share your conclusions.

    Many Thanks as always,

    Sid

    Reply
  • Thank you Sid. Do you have a link to Dr. Rower article?

    Reply
  • Liam Bayly ,

    Dr. Geo, thank you for your quick response. The phrase that bothers me the most in the article is this one: “…Alan Kristal, Dr.P.H, said: ‘we’ve shown once again that use of nutritional supplements may be harmful.’” It seems to me that there is something deeper going on right here.

    As a scientist, what saddens me is science and research has been reduced to studies that produce desired results rather than science and research that seeks to discover regardless of the outcome. You mentioned three studies – one occurred over a long period of time and the other two utilized large sampling pools. These types of studies are required in order to understand the impact of anything we take in to our bodies. Time and sample pool size are our friends in research. The longer the time period and the larger the sample pool, the more accurate the findings.

    To me, the controls required to determine, absolutely, the affect of any food substance on our bodies is staggering. As some have mentioned, what did the individuals used in the studies consume? What is their genetic history? What is there cultural background? What is their environmental surroundings? Were they healthy individuals to begin with?

    As Eden points out it seems that using data representing a single point in time is unnerving. I am a geologist. I can’t imagine what my fellow geologists would say if I opined that, because I found a rock in the river means that a volcano erupted yesterday.

    Reply
  • Thank you Liam. Great points.

    Reply
  • JohnnyWhite ,

    Good post, thanks. Something deeper indeed. Kristal’s quote you give reveals something almost sinister, the words “ONCE AGAIN”. (Caps mine) ” …we’ve shown once again” … What comes to my mind first is, who or what has a huge ANTI-supplement position? Big Pharma.

    Reply
  • Thanks, great site; it’s clearly the most comprehensive and generally well done that I have found as I try to access info on this newest so -called study.

    But about the associated text I’ve been reading here, am I missing something or do the benefits touted(according to studies) all address eating FISH per se, as opposed to supplements?
    Thanks in advance for your reply.
    Wishing you and all your readers good health,
    Sherrie

    Reply
  • Hi Sherrie, none of the Brasky studies cited here make any correlation between fish oil consumption and prostate cancer. That is the other problem with this study. Thanks for your input.

    Reply
  • Thanks Dr. Geo for broadening the spotlight on this issue. I’ve been following the Bransky studies since they first hit the science blogs. I am very curious, as Eden mentioned, to see a more in-depth and longterm analysis of the relationship between pca and marine lipid levels. How long were these men monitored and how often? What were their omega 3 levels like? And why were they taking fish oil supplements? I ratched down my fish oil supplements by half at the end of last year, just in case.

    I look forward to your continued coverage of this important information.

    Reply
  • Dennis Mason ,

    I am very worried about this study, I have been on prescription Lovaza fish oil for about 9 mo’s. My doctor just uped me to 4 a day to lower my triglycerides, which where 298. I’m not sure if I should stop taking them?

    Reply
  • Dennis, follow your doctors advise. I do not think he would take you off Lovaza based on this latest study. He shouldn’t.
    Thank you for your comment.

    Reply
  • Ed Dwulet ,

    Pertinent questions that I can’t find answers to in any of the news coverage of this story: (1) how long do the chemical markers of fish oil remain in blood? We’re these one time readings of omega 3 blood levels? Do these markers remain elevated for a long period of time? Does daily consumption of fish or fish oil result in ever higher and higher levels of these blood markers? i.e. So they have a guy with aggressive PC and they measure the omega 3′s in his blood one time and its “high” – does that mean he’s been taking fish oil pills for years? Or that he had salmon for dinner the night before? (2)Its also not clear. Were all the subjects in this study from the SELECT trial? one article seemed to imply the 800 or so cancer patients were from the Hutchinson Cancer Center in Seattle -if these were men from the Seattle area that alone would probably mean they were more likely to be eating a lot more fish than the SELECT controls and bias the results. But I have to think (hope) this research would not have gotten as far as it did if that were the case. But you never know.

    Reply
  • Two other excellent postings on this topic by two reputable doctors, Dr. Michael Murray and Dr. Duffy Mackay

    http://doctormurray.com/how-a-selected-bad-study-became-big-news/

    http://www.crnusa.org/CRNPR13-Omega3071113.html

    Reply
  • David Proch ,

    The right type of Vitamin E is potent. Vitamin E without Gamma is junk!

    Reply
  • David Proch ,
    Reply
  • Excellent Post by Dr. Ronald Hoffman on this topic.

    http://www.drhoffman.com/page.cfm/1213

    Reply
  • Ralph Adamo ,

    I am always very suspicious of any so-called study that targets the supplement industry, particularly on a supplement which threatens the pharmaceutical industry. Therefore, I would like to know WHO SPONSORED AND PAID FOR THIS SO-CALLED STUDY? My extraordinarily accurate bullsheis detector tells me that a big pharmaceutical manufacturing company paid for and sponsored this canard. Pfizer is a likely candidate. Until the funding source is revealed, this study should be ignored as dangerous propaganda.

    Reply
  • Wayne ,

    I haven’t read the study but is it possible once they found out they had cancer that they started taking and eating much more fish products as they are promoted to fight prostate cancer hence their omega 3 levels increased after they had cancer?

    Reply
  • John Olaf ,

    Both Brasky studies were prospective: blood was taken prior to diagnosis. They differ from cohorts because no one can afford to analyze blood on 35,000 people when only ~3000 are needed to find same results.

    Reply
  • John Olaf ,

    Also, I couldnt help but notice that you sell fish/omega3 products.

    Reply
  • Ed Dwulet ,

    I have some additional questions and comments that have not been addressed in any of the press reporting of this story and I would appreciate Dr Geo’s opinion: (1) What was this study’s definition of “aggressive” cancer? Was it simply something like one biopsy finding of any % Gleason 7? Or what? Definitions matter and I’m wondering if “aggressive” was truly deadly aggressive pc or the medical industrial complex’s money seeking definition that pushes men into seeking “aggressive” treatment at the lowest threshold. (2) Something I’ve noted in other large pc studies is that participants seem to have a higher rate of pc than the general population i.e. someone participating in the SELECT study is more likely to be screened for pc esp given the fact that it was halted early. More testing leads to more diagnosis and more findings of insignificant amounts of G7 and hence more “cancer” and more “aggressive” cancer and more blame all around, whether it be vitamin e or fish oil. Thanks

    Reply
  • Ed Dwulet ,

    My point being that a man’s real world real risk of actually dying of PC (the end point we are all actually concerned about) is unlikely to be directly affected by fish oil or vitamin “anything” intake. Studies like this are for the most parts games with statistics.

    Reply
  • Your Mom ,

    Ed,
    Of course the rate is higher; the trials are done in men who are at higher risk; otherwise there would be less events to study. This is done for efficiency and by design.

    Reply
  • Joe V ,

    Thank you for the clarification. Fish oil has improved much of my life from leg cramps to increased brain functionality.
    If I stopped taking fish oil my legs will cramp at night. My focus and attention is much improved and I would hate to give these up.
    This study smells (pardon the pun) fishy.

    Reply

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