Fish Oil Increases Risk for Prostate Cancer, New Study ?

Fish Oil Increases Risk for Prostate Cancer, New Study ?

by Jeffrey Dach MD

I received an email from a concerned patient who consumes Omega 3 Fish Oil every day as part of his nutritional supplement program to prevent heart disease.  He was concerned because he saw an article in the paper reporting Fish Oil increases risk for prostate cancer.  The fish oil-prostate study was actually published in 2011 by Theodore Brasky of Ohio State University Comprehensive Cancer Center.(1-3)  A new report on this same data just came out in a new article July 10 in the Journal of the National Cancer Institute by Dr Brasky

Above Image:Above image Striped Bass Courtesy of WIkimedia Commons.

COntaminated FISHIn Dr Brasky’s study, the type of fish or fish oil consumed was not controlled.   The study did not use any particular brand or quality of fish oil, instead, a questionnaire was sent to the participant, and blood levels of omega 3 fatty acids were measured in the patients. So, it is highly likely that the fish consumed or the fish oils used varied in quality and some or all may have been contaminated with carcinogenic chemicals,

Serum Omega 3 Fatty Acid Level – Surrogate Marker for Carcinogenic Contaminants in Fish

So, in my opinion, the Brasky Fish Oil study proves that carcinogenic chemicals in fish cause cancer.  Measuring the amount of Omega 3 in the blood is a surrogate marker for contaminated fish and fish oil consumption.  These contaminants cause cancer.   We already knew that.  Perhaps the most studied carcinogenic chemicals that accumulate in fish are PCB’s and Dioxins  which are known carcinogens. (19-20) So the correct answer is that fish oil does not cause cancer.  Carcinogenic chemicals which contaminate the fish DO CAUSE cancer. (11)

Previous Studies Fish Oil Decreases Mortality from Prostate Cancer

Multiple previous previous studies show that fish oil consumption is associated with decreased mortality from prostate cancer.(4-10).

Self Censorship in the News

Cottage Grove Sign Warning Contaminated FishIf you read the news reports, you will notice  a form of self censorship.  The journalists avoid mentioning the fact that fish and fish oils are contaminated by environmental pollutants which are carcinogenic.  Apparently that might annoy their corporate sponsors who are the source of the environmental pollution.


Why Take Fish Oil?

The main reason most of my patients take fish oil is the benefit for cardiovascular disease prevention.  A recent Harvard study by Mozaffarian in the  Annals of Internal Medicine showed that higher omega 3 fatty acid levels in the blood were associated with a 20-30% reduction in mortality from cardiovascular disease.(22)

Use Pure Omega 3 Oils Avoid Carcinogenic Contamination

My recommended fish oil supplement is the DHA Ultimate by Pure Encapsulations.  This is a solvent-free, supercritical CO2 based extraction fish oil concentrate.  The manufacturer uses low temperature, oxygen-free processing to prevent oxidation reactions.  Each batch of fish oils is third party tested for environmental contaminants, oxidation,  rancidity, and microbial contamination.  The third party testing assures the product is free of heavy metals (< 0.1 ppm),  Dioxins/furans (< 2 ppt),  Dioxin-like PCBs (< 3 ppt ) and  PCBs (< 0.09 ppm).

Articles With Related Interest

Mercury Sensitivity and the Environment

Author: Jeffrey Dach MD

Links and References:

Brasky, Theodore M., et al. “Serum Phospholipid Fatty Acids and Prostate Cancer Risk: Results From the Prostate Cancer Prevention Trial.” American Journal of Epidemiology 173.12 (2011): 1429.

J Natl Cancer Inst. 2013 Jul 10. [Epub ahead of print]
Plasma Phospholipid Fatty Acids and Prostate Cancer Risk in the SELECT Trial.
Brasky TM, Darke AK, Song X, Tangen CM, Goodman PJ, Thompson IM, Meyskens FL Jr, Goodman GE, Minasian LM, Parnes HL, Klein EA, Kristal AR.
Department of Internal Medicine, Division of Cancer Prevention and Control, The Ohio State University College of Medicine, Columbus, OH (TMB);

BACKGROUND:Studies of dietary ω-3 fatty acid intake and prostate cancer risk are inconsistent; however, recent large prospective studies have found increased risk of prostate cancer among men with high blood concentrations of long-chain ω-3 polyunsaturated fatty acids ([LCω-3PUFA] 20:5ω3; 22:5ω3; 22:6ω3]. This case-cohort study examines associations between plasma phospholipid fatty acids and prostate cancer risk among participants in the Selenium and Vitamin E Cancer Prevention Trial.
METHODS:Case subjects were 834 men diagnosed with prostate cancer, of which 156 had high-grade cancer. The subcohort consisted of 1393 men selected randomly at baseline and from within strata frequency matched to case subjects on age and race. Proportional hazards models estimated hazard ratios (HR) and 95% confidence intervals (CI) for associations between fatty acids and prostate cancer risk overall and by grade. All statistical tests were two-sided.
RESULTS:Compared with men in the lowest quartiles of LCω-3PUFA, men in the highest quartile had increased risks for low-grade (HR = 1.44, 95% CI = 1.08 to 1.93), high-grade (HR = 1.71, 95% CI = 1.00 to 2.94), and total prostate cancer (HR = 1.43, 95% CI = 1.09 to 1.88). Associations were similar for individual long-chain ω-3 fatty acids. Higher linoleic acid (ω-6) was associated with reduced risks of low-grade (HR = 0.75, 95% CI = 0.56 to 0.99) and total prostate cancer (HR = 0.77, 95% CI = 0.59 to 1.01); however, there was no dose response.

CONCLUSIONS:This study confirms previous reports of increased prostate cancer risk among men with high blood concentrations of LCω-3PUFA. The consistency of these findings suggests that these fatty acids are involved in prostate tumorigenesis. Recommendations to increase LCω-3PUFA intake should consider its potential risks.

Brasky TM, Darke AK, Song X, et al. Plasma phospholipid fatty acids and prostate cancer risk in the SELECT Trial. J National Cancer Inst Online.   July 10, 2013

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. Our analyses provide no strong evidence of a protective association of fish consumption with prostate cancer incidence but showed a significant 63% reduction in prostate cancer-specific mortality.


Terry P, Lichtenstein P, Feychting M, Ahlbom A, Wolk A. Fatty fish consumption and risk of prostate cancer. Lancet 2001; 357: 1764-6 Our results suggest that fish consumption could be associated with decreased risk of prostate cancer.

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. These results suggest that fish intake is unrelated to prostate cancer incidence but may improve prostate cancer survival.

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.
Cancer Epidemiol Biomarkers Prev. 2003 Jan;12(1):64-7.
A prospective study of intake of fish and marine fatty acids and prostate cancer.
Augustsson K, Michaud DS, Rimm EB, Leitzmann MF, Stampfer MJ, Willett WC, Giovannucci E.Source Department of Nutrition, Harvard School of Public Health, Harvard Medical School, Boston, Massachusetts, USA.
Abstract Experimental studies suggest that marine fatty acids have an antitumor effect on prostate tumor cells. The aim of this study was to investigate whether high consumption of fish and marine fatty acids reduces the risk of prostate cancer in humans. We followed 47882 men participating in the Health Professionals Follow-up Study. Dietary intake was assessed in 1986, 1990, and 1994, using a validated food frequency questionnaire. During 12 years of follow-up, 2482 cases of prostate cancer were diagnosed, of which 617 were diagnosed as advanced prostate cancer including 278 metastatic prostate cancers. Eating fish more than three times per week was associated with a reduced risk of prostate cancer, and the strongest association was for metastatic cancer (multivariate relative risk, 0.56; 95% confidence interval, 0.37-0.86, compared with infrequent consumption, i.e., less than twice per month). Intake of marine fatty acids from food showed a similar but weaker association. Each additional daily intake of 0.5 g of marine fatty acid from food was associated with a 24% decreased risk of metastatic cancer. We found that men with high consumption of fish had a lower risk of prostate cancer, especially for metastatic cancer. Marine fatty acids may account for part of the effect, but other factors in fish may also play a role.
Norrish AE, Skeaff CM, Arribas GL, Sharpe SJ, Jackson RT. Prostate cancer risk and consumption of fish oils: a dietary biomarker-based case-control study. Br J Cancer 1999;81:1238-42.7.  These analyses support evidence from in vitro experiments for a reduced risk of prostate cancer associated with dietary fish oils, possibly acting via inhibition of arachidonic acid-derived eicosanoid biosynthesis.

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):204-16.8.

Stott-Miller M, Neuhouser ML, Stanford JL. Consumption of deep-fried foods and risk of prostate cancer.  Prostate. 2013 Jun;73(9):960-9.


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;98(1):104-13.

These results suggest that a higher burden of PCBs that are CAR agonists may be positively associated with an increased risk of prostate cancer

12).  Mullins JK, Loeb S. Environmental exposures and prostate cancer. Urol Oncol. 2012 Mar-Apr;30(2):216-9.

A high percentage of omega-3 fatty acids in the blood is linked to an increased risk of aggressive prostate cancer.  Conversely, a high percentage of trans-fatty acids is linked with a lower risk..  SEATTLE — Apr 25, 2011 — 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.

Conversely, the study also found that men with the highest blood ratios of trans-fatty acids — which are linked to inflammation and heart disease and abundant in processed foods that contain partially hydrogenated vegetable oils — had a 50 percent reduction in the risk of high-grade prostate cancer. In addition, neither of these fats was associated with the risk of low-grade prostate cancer risk. The researchers also found that omega-6 fatty acids, which are found in most vegetable oils and are linked to inflammation and heart disease, were not associated with prostate cancer risk. They also found that none of the fats were associated with the risk of low-grade prostate cancer.

These findings by Theodore M. Brasky, Ph.D., and colleagues in the Hutchinson Center’s Public Health Sciences Division were published online April 25 in the American Journal of Epidemiology.

14) Fish Oil Tied to Prostate Risk but Some Experts Are Skeptical ABC NEws

The new study, published today in the Journal of the National Cancer Institute, suggests that men who have higher levels of omega-3 fatty acids in their system face a 43 percent increased risk of developing prostate cancer and a 71 percent increased risk of the high-grade form of the disease.

To determine this, the researchers relied on data from a past study that examined the blood concentrations of omega-3 polyunsaturated fatty acids in 834 men with prostate cancer and 1,393 men without prostate cancer. When they did this, these researchers found an association between high omega-3 levels and the occurrence of prostate cancer.  But lead study author Dr. Theodore Brasky of Ohio State University Comprehensive Cancer Center

Men might want to shun fish oils, study shows.  Fresh research at the Fred Hutchinson Cancer Research Center suggests a link between an elevated risk of prostate cancer and fish oils. By Sarah Zhang Seattle Times staff reporter

Fish oils may raise prostate cancer risks, study confirms
Maggie Fox, Senior Writer NBC News

17) Too Much Fish Oil Might Boost Prostate Cancer Risk, Study Says
Often-fatal aggressive disease of particular concern
July 10, 2013 By Steven Reinberg  HealthDay Reporter

18)    Any thoughts?   I’m taking quite a bit.

Dioxins and dioxin-like PCBs in farmed and wild fish and shellfish
Food Survey Information Sheet 03/06

Hum Reprod Update. 2001 May-Jun;7(3):331-9.
Human health effects of dioxins: cancer, reproductive and endocrine system effects.
Kogevinas M.SourceInstitut Municipal d’Investigació Medica, Respiratory and Environmental Health Research Unit, Barcelona, Spain.

Polychlorinated dioxins, furans and polychlorinated benzene constitute a family of toxic persistent environmental pollutants. In Europe, environmental concentrations increased slowly throughout this century until the late 1980s. Dioxins have been shown to be carcinogenic in animals and humans. In humans, excess risks were observed for all cancers, without any specific cancer predominating. In specific cohorts, excess risks were observed for reproductive cancers (breast female, endometrium, breast male, testis) but, overall, the pattern is inconsistent. In animals, endocrine, reproductive and developmental effects are among the most sensitive to dioxin exposure. Decreased sperm counts in rats and endometriosis in rhesus monkeys occur at concentrations 10 times higher than current human exposure. In humans, results are inconsistent regarding changes in concentrations of reproductive hormones. A modification of the sex ratio at birth was described in Seveso. There exist no data on effects such as endometriosis or time-to-pregnancy. Small alterations in thyroid function have occasionally been found. Increased risk for diabetes was seen in Seveso and a herbicide applicators cohort but, overall, results were inconsistent. Experimental data indicate that endocrine and reproductive effects should be among the most sensitive effects in both animals and humans. Epidemiological studies have evaluated only a few of these effects.

Mercury in Stream Ecosystems—New Studies Initiated by the U.S. Geological Survey By Mark E. Brigham, David P. Krabbenhoft, and Pixie A. Hamilton U.S. Geological Survey Fact Sheet 016-03  Mercury in Stream Ecosystems New Studies Initiated by US Geological Survey Mark Brigham David Krabbenhoft Pixie Hamilton

plasma Phospholipid Long-Chain ω-3 Fatty Acids and Total and Cause-Specific Mortality in Older Adults: A Cohort Study  by Dariush Mozaffarian, MD, DrPH; Rozenn N. Lemaitre, PhD, MPH; Irena B. King, PhD; Xiaoling Song, PhD; Hongyan Huang, PhD; Frank M. Sacks, MD; Eric B. Rimm, ScD; Molin Wang, PhD; and David S. Siscovick, MD, MPH
Mozaffarian D, Lemaitre RN, King IB, Song X, Huang H, Sacks FM, Rimm EB, Wang M, Siscovick DS.Harvard School of Public Health, 665 Huntington Avenue, Boston, MA 02115, USA.

Phospholipid fatty acid levels and cardiovascular risk factors were measured in 1992. Relationships with total and cause-specific mortality and incident fatal or nonfatal CHD and stroke through 2008 were assessed.

CONCLUSION:Higher circulating individual and total ω3-PUFA levels are associated with lower total mortality, especially CHD death, in older adults.



Experts slam omega-3 link to prostate cancer as overblown ‘scaremongering’A raft of industry and academic experts have slammed the publication of a recent study claiming to ‘confirm’ a link between long-chain omega-3s and an increased risk of prostate cancer – arguing that the authors conclusions are overblown and have caused widespread scaremongering


What do other Studies Show?In addition to population-based studies, several studies have been conducted that were actually designed to determine the effects of fish and fish oil consumption in prostate cancer. In a detailed meta-analysis conducted in 2010, while fish consumption did not affect prostate cancer incidence, it was associated with a 63% reduced mortality due to prostate cancer.2 A meta-analysis examines all previously conducted studies. Here are some of the results from some of these studies:Researchers investigated the effect of dietary fatty fish intake among 6,272 Swedish men who were followed for 30 years. Results showed that men who ate no fish had a two- to three-fold increase in the risk of developing prostate cancer compared with those who consumed large amounts of fish in their diet.3
Data from the Physician’s Health Study, a study spanning 22 years, found that fish consumption (≥5 times per week) reduced the risk of dying from prostate cancer by 36%.4 -specific death.
A study conducted by the Harvard School of Public Health that involved 47,882 men over twelve years found that 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%.5
In one of the best-designed studies, researchers in New Zealand examined the relationship between prostate cancer risk and EPA+ DHA in red blood cells (a more reflective marker for long-term omega-3 fatty acid intake). Higher levels of EPA+DHA were associated with a 40% reduced risk of prostate cancer.6In a study of 47,866 US men aged 40-75 years with no cancer history in 1986 who were followed for 14 years EPA+DHA intake at the highest levels was associated with a 26% reduced risk of developing prostate cancer.7While some studies make an important distinction, others do not. When ascertaining the benefits of fish consumption it is important to find out how the fish is being prepared. For example, regular ingestion of fried fish was associated with a 32% increased risk for prostate cancer.8 In addition, many studies do 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 asPCBs, heavy metals, and other toxic chemicals.9, 10 These are important considerations.———————————————————————————————————————————–

Posted by KurtisFrank on Jul 11, 2013 Fish Oil Increases Risk of Prostate Cancer?
A new study has been making its rounds online claiming that fish oil causes prostate cancer, and more specifically the claim is that fish oil supplementation causes a 71% increase in high grade prostate cancer.  The study in question is one that appears to be a study based off of the SELECT trials (a large trial initially investigating the link between vitamin E and selenium with prostate cancer) which initially did not find a protective effect of supplementation on prostate cancer, but say an increased risk associated with vitamin E occurred during prolonged follow-up. This led to the current study.

Savage Nation Radio Show
michael savage UC Berkely phd in epidemiology and nutrition
bogus study in cahoots with drug industry
out to get vitamins and natural products
conspiracy against natural productsDr Anthony Damico PhD MIT expertise in prostate Cancer=study cannot make the conclusion .  It is an” frameborder=”0″ allowfullscreen></iframe>


Jeffrey Dach MD
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Fish Oil Increases Risk for Prostate Cancer, New Study ?
Article Name
Fish Oil Increases Risk for Prostate Cancer, New Study ?
I received an email from a concerned patient who consumes Omega 3 Fish Oil every day as part of his nutritional supplement program to prevent heart disease.
Jeffrey Dach MD
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2 thoughts on “Fish Oil Increases Risk for Prostate Cancer, New Study ?

    • Hi Brian,

      It is commonly believed that Trans Fats and Omega 6 oils are inflammatory, while the Omega three oils are anti-inflammatory.

      For example, some patients with rheumatoid arthritis on high dose fish oil can discontinue other NSAID anti-inflammatory drugs.

      From William Davis MD Track Your Plaque:”Two large studies have demonstrated that higher omega-3 blood (the level in red blood cells, or RBCs) levels were associated with reduced likelihood of sudden cardiac death. The risk for sudden cardiac death was 10-fold higher for the lowest omega-3 RBC levels compared to the highest. Harris WS 2008;

      JAMA. 1995 Nov 1;274(17):1363-7.
      Dietary intake and cell membrane levels of long-chain n-3 polyunsaturated fatty acids and the risk of primary cardiac arrest.
      Siscovick DS1, Raghunathan TE, King I, Weinmann S, Wicklund KG, Albright J, Bovbjerg V, Arbogast P, Smith H, Kushi LH, et al.

      Dietary intake of long-chain n-3 polyunsaturated fatty acids and the risk of primary cardiac arrest. Siscovick DS, Raghunathan T, King I, Weinmann S, Bovbjerg VE, Kushi L, Cobb LA, Copass MK, Psaty BM, Lemaitre R, Retzlaff B, Knopp RH.
      Am J Clin Nutr. 2000 Jan;71(1 Suppl):208S-12S.

      See more at:

      On the basis of published studies like these, DHA Fish oil is recommended by William Davis MD as a preventive measure for Cardiovascular Disease. I assume you would disagree with this.

      Thanks for the comment Brian. I enjoyed your talk at the meeting and you signed a copy of your book for me after.

      regards from jeffrey dach md

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