Many of our concierge medicine patients have been coming to us with anxious questions posed by the recently published study about the correlation between fish oil intake and an increase in risk of cancer. The study, published in the National Institute of Cancer Journal from the SELECT trial, released that they found a possible link between higher levels of omega-3 fatty acids in the blood and the risk of prostate cancer. Omega-3s from fish oil pills are one of the most popular supplements in America, and therefore the media has taken off with these study results. Here is a little bit about what we know about the study regardless of the media hype.
First and foremost, it is important to remember that a correlation between fish oil and prostate cancer DOES NOT necessarily mean that fish oil or omega-3 fatty acids CAUSEcancer. Correlation does not equal causation. Study results should be interpreted in the backdrop of the question the study was designed to answer. Clinical trials and the scientific method DO have their limitations. There have been a multitude of studies demonstrating the benefits of omega-3 fatty acids in the diet, so without a doubt, these findings come as a bit of a surprise. For the science savvy, there have even been some biological pathways identified explaining how DHA (a component of fish oil) could lower prostate cancer risk. We had the Director of our Wellness Program, Marilyn Chown RN, BSN, MPH, take a deeper look at the original study to give us her take on the article.
Marilyn’s first note is that the source study (SELECT trial) from which this population was derived was created to look at the impact of selenium and vitamin E on prostate cancer and did not set out to address the link between omega-3 fatty acids and prostate cancer. When a study comes up with findings that it did not initially intend to look at, the only conclusions that can be made are “hypothesis generating” meaning that a study would need to be designed to look at this particular relationship from the outset to really test this hypothesis.
Another topic worth mentioning is that the study measured omega-3 blood levels in the participating men, and did not include information on their eating habits. Researchers cannot determine that the polyunsaturated fats were a part of the problem outside of other dietary factors. As with all things nutrition, it is impossible to distill out one nutrient and one effect. Most likely, if the study participants were consuming the Standard American Diet, the whole group had a very poor fatty acid profile regardless of whether they had cancer or not. Again, a study should be designed to address the link between prostate cancer and fatty acids that account for these variables.
We stand by our recommendation that taking a daily omega-3 fatty acid supplement in the form of a high quality fish oil is beneficial to your health with very few detrimental effects. As with all supplements, please speak with your doctor before starting or stopping your fish oil intake. All in all, we hope that this information can shed a little bit of light on this hot topic.
If you have any additional questions surrounding this study or about omega-3 fatty acids in general, please contact us and we would be happy to help.