A study performed by the Fred Hutchinson Cancer Research Center in Seattle, Washington and also reported by the American Cancer Society has not only made some headlines, but has come under withering criticism by several groups and the medical community. The study reported a link between ingestion of Omega-3 fatty acids and increased risk of prostate cancer. Patients have asked us about the study results. After all, we have been told eating deep-water fish that have high levels of Omega-3 fatty acids are healthy for us. This group of fish includes, but is not limited to, tuna and salmon. There is true investigative science, junk science and “science” of someone’s opinion on how we should live and what we should eat.
Details and Conclusions of the Study
The program began as a study of Vitamin E and Selenium’s role in possibly lowering the risk of cancer of the prostate. The study included 35,000 men from Canada, Puerto Rico and the United States. These researchers found that those men with the highest blood levels of Omega-3 fatty acids revealed a 43% increased risk of developing cancer in the prostate. They went on to report 71% had the possibility to develop a higher grade of prostate cancer.
What Others are Saying About Omega-3 and Prostate Cancer
Dr. Andrew Weil commented that even though this study made big headlines, it did not accurately portray the findings and he goes on to outline the study’s weakness and inaccuracies. His conclusions are as follows:
- The study didn’t compare the risk of cancer in men that don’t eat fish or take omega-3 supplements to those that do. There was no data regarding the intake of fish or supplements in the study group.
- The conclusions were based on a single blood draw.
- The study was based upon plasma phospholipids which only tell you that fish or supplementation happened recently. The blood levels stay high for approximately 4 to 12 hours after ingestion of fish or Omega-3’s. If no additional fish is eaten or Omega-3’s ingested, the blood levels are clear of the phospholipids!
- He went on to report there is an “unfortunate combination of questionable science, unwarranted conclusions, and dreadful media coverage”.
These sentiments are echoed by Medscape and Dr. Gerald Chodak, a physician at Midwest Prostate and Urology Health Center. He is very critical of this research and provides several items to support his contention. His comments on the study include the following:
- No Validation Of The Data
- No Standardization Of The Procedure
- There Was Not A Reliable Control Group
- Study Had Many Design Flaws
The sentiments are continued with articles from NUTRA Ingredients. Alan Ruth, PhD of the Irish Health Trade Association outlined in an article several comments from Dr. Anthony D’Amico, a professor of Radiation Oncology at Harvard Medical School. Dr. D’Amico is also affiliated with Dana-Farber Cancer Institute where he has gained notoriety for working with the detection of prostate cancer and directing its treatment. He has been published in over 140 peer-reviewed publications as well as co-edited four textbooks in Urologic Oncology. He has made the following comments about this study:
- Conclusions that the authors are trying to make in this type of study did not properly demonstrate a cause and effect. It could not be concluded that if you take fish oil you will get an aggressive kind of prostate cancer.
- It appears the authors tried to adjust the study for an association between Omega-3 fatty acids and prostate cancer and they left out very important risk factors for prostate cancer.
- He went on to comment that at the end of the study it was an association that at its best is very weak. The study was further weakened by the facts that known predictors for prostate cancer were not taken into account.
- The scientific strength of this study is at best, weak.
The comments from other researchers and clinicians support these conclusions. They also are very critical of the press coverage to sensationalize the findings. This has the tendency to frighten the population. Steve Mister, President and CEO of The Council for Responsible Nutrition (CRN), commented in an article in NUTRA Ingredients the following:
- “Even as I read the press coverage, I was struck by what an amazing example this study is of how inconclusive research findings somehow become sweeping recommendations for consumers that don’t reflect what the science actually shows.”
- “Immediately, there are some problems with their conclusions. An observational study cannot demonstrate causality; just an association – regardless of the assertions the authors made in their press release. Note too that the analysis of the blood did not identify the source of the Omega-3 fish intake or supplements.”
- “It’s even more curious that there was no apparent effect on cancer risk from smoking, heavy drinking or larger body mass index (BMI) – all of which are commonly known to increase cancer risk.”
He went on to comment that the authors of this study concluded that Omega-3 fatty acid intakes from nutritional supplementation is considered a potential risk for prostate cancer. This statement did not appear in the original work, but appeared to be a “leap to judgment” that would not have passed scrutiny in a peer-reviewed study.
What are We to Conclude From this Study?
When sensational headlines about a food or product appear extensively in the media you should wait until critical researchers review the conclusions. Remember the coffee scare? There are numerous studies such as that, which start out creating worry in the general population and later it is found the data is skewed or manipulated to arrive at a conclusion the researchers are trying to prove. The motives and bias of the researchers have to be evaluated. Who paid for the research may direct the “outcome” to favor that payer.
There are excellent researchers who are discovering important data to make our lives safer and healthier. As always, with any group there is a small contingent that puts skepticism and doubt in the findings of all research. Check with your health care provider if you have any questions regarding the headlines of some major health breakthrough or warning.