Wait! Don’t Stop Taking Your Fish Oil Supplements!

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Yet again, the news media was all-abuzz with irresponsible over-reporting of misleading information. The headlines went something like: Fish Oil Supplements Linked To Increased Risk Of Prostate Cancer.

The media frenzy was about a recently released “analysis” of a very small subgroup of study participants suggesting that omega-3 fatty acid levels in the blood were linked to increased risks of prostate cancer. This “analysis” was conducted by researchers from The Ohio State University Comprehensive Cancer Center at the Fred Hutchinson Cancer Center in Seattle, WA. It was published in in the Journal of the National Cancer Institute.

What’s Wrong With This Analysis?

First of all, let me explain why I am calling it an “analysis” and not the study it was reported to be in the media. There is a very important distinction and it’s good to understand the difference in trying to assess the appropriateness of the info being reported. A study means the researchers started with a hypothesis and set up a scientific process to either support or disprove it. An “analysis”  means they looked back at data from one or more studies and found associations or connections that were not even part of the hypothesis of the study design. Therefore, no controls or guidelines for interpretation were set up.

An “analysis”may be valuable sometimes, but mostly in recognizing a connection or association that may warrant further study, with controls and guidelines included. An observation of a connection between two things does not mean one causes the other, without further critical evaluation. It should not be interpreted as study results. Unfortunately, the media all too often misleads the public in this way.

What’s Missing In The Reporting Of This Analysis?

I will briefly list here some important considerations that were not included in any of the reporting.

  • The “analysis” used data from a trial looking at vitamin E and selenium for cancer prevention, it had nothing to do with looking at omega-3 and prostate cancer.
  • No omega-3 fish oil supplements or any supplements were used, or given to any participants in the study.
  • Only one single blood test was done at the time of the study onset for omega-3 fatty acid levels in the blood even though the study subjects were followed for 6 -9 years. Yet, only ONE blood level measurement was done in all that time.
  • The conclusion they made from that single blood test was that an only slightly higher omega-3 level was associated with an increased risk of low-grade and high-grade prostate cancer. In fact, the actual omega-3 levels were still very low, even for those with the highest level. They were still only 40% of the level in health-conscious people taking fish oil supplements. So the differences were minor.
  • The blood level of omega-3 only reflects a very short-term dietary response, not long-term intake. Consuming a fish dinner the night before the blood draw or taking fish oil capsules just hours before could create a temporary higher blood level of omega-3. But a higher temporary blood level does not mean a higher overall omega-3 fatty status in the body cells. Maintaining a higher level in the cells requires longer-term consistent consumption of omega-3 fatty acids.
  • There was no comparison of omega-3 levels and family history and PSA levels, which are real known risk factors for prostate cancer, and likely causes of higher levels of cancer.

How Does This Analysis Compare To Other Current Scientific Literature?

Let me be very clear here and put this in context. There have literally been thousands of published studies on omega-3 fats. These have included not just observational analyses, but also randomized controlled studies as well, spanning over three decades.

The scientific literature overwhelmingly identifies diets high in saturated fats, trans fatty acids and omega-6 fats (like vegetable oils) as associated with greater risk of prostate cancer. And a higher intake of omega – fats with reduced risk. The current evidence strongly supports fish oil supplementation for humans, especially as we age for its anti-inflammatory effect, reducing heart risk, reducing blood pressure, and decreased proliferation of cancer cells, to name a few of it’s studied benefits. Even mainstream medicine has taken note of the substantial benefits of omega-3 fats in fish oil. Even Big Pharma has jumped on the bandwagon creating prescription fish oil products.

Of course, in an effort to enhance your health with increased omega-3 fats, care should be taken. It’s important to eat wild fish with low potential for toxins. And avoid fish oil supplements that are not tested for removal of all heavy metals, PCB’s and other toxins. This is especially important because fish, like humans, store toxins in fatty tissue. Taking cheap supplements that are not purified (and tested by outside labs) can concentrate these toxins in your body. When it comes to fish oil, it is especially important to use quality supplements that are tested for purity.

I am happy to send a copy of a more detailed rebuttal of the media frenzy reports on fish oil and prostate cancer. It was prepared by health care practitioners and includes many pages of footnotes. If interested- just email me.

For future info, See my article A Quick Guide for Evaluating Health Studies in the Media