By Kimberly Duffels BSc.
When the current state of knowledge is challenged it is common that the media seizes the opportunity to sensationalize that research, despite any flaws and shortcomings in the publication, and often has a large impact on their audience’s views. A study published July 11th this year in the Journal of the National Cancer Institute by Brasky et al., Plasma Phospholipid Fatty Acids and Prostate Cancer Risk in the SELECT Trial [1], provides a prime example of this media-consumer relationship. The paper brought into question the well-known health benefits of fish oil, claiming that consumption of omega-3 fatty acid rich foods and supplementation leads to an increased risk of prostate cancer. This is not to say that we as consumers should not question the current state of knowledge, but it is concerning when the paper making such a grandiose claim does not have scientific evidence to support their conclusion and potentially deter people from making decisions to benefit their health.
What We Know and Why We Need Omega-3s:
[[{“type”:”media”,”view_mode”:”media_large”,”fid”:”161″,”attributes”:{“class”:”media-image alignright size-medium wp-image-4972″,”typeof”:”foaf:Image”,”style”:””,”width”:”300″,”height”:”349″,”alt”:”omega foods”}}]]Long chain omega-3 fatty acids (LC n-3 FA) are sourced mainly in cold water organisms, especially marine fish like salmon and sardines as well as flax and hemp seeds and walnuts. The reason they are essential to fish is the same reason for why they are essential for humans: They are polyunsaturated fats meaning they have many double hydrogen bonds. For fish these fats comprise their membranes and inhibit the membranes from solidifying in cold water, which would inhibit cellular function [2]. For us, they are similarly incorporated into numerous tissues, but are essential buildings blocks for all the fats in our bodies.
Eicosapentaeoic acid (EPA) and Docosahexanoic acid (DHA) are two types of LC n-3 FA that are essential to our physiological functioning. Tissues with large concentrations of these fats are the retina, myocardium (heart muscle), red blood cells, liver, kidney, your brain and the rest of your nervous system. With such an essential role in our body, there is no question as to the benefits of increasing EPA and DHA intake. It is for these reasons that EPA and DHA supplementation have been found to support the development of children’s brains and maintenance of our brains and nervous system [2,3]. Also, fish oils have been found to have cardioprotective effects in reducing the risk of heart disease, lowering serum triglycerides (fats) and low density lipoproteins(“bad” cholesterol), as well as a role in reducing inflammation in the body which reduces chronic and rapid cell turnover that often contribute to increasing the risk of cancer [2,3].
You may hear LC n-3 FA to be considered essential. This is because our body does not produce them and we must get them from our diets. From whole food sources, we only ingest 18% EPA and 12% DHA and only a fraction of this actually makes it to its target tissues to be useful after absorption and circulation. Marine concentrates and vegan supplements contain up to 90% EPA and DHA increasing the probability of absorption in the cells. This illustrates, that from our diets alone, EPA and DHA intake is insufficient and that our bodies need a bit of a boost to help us get enough fats to support our cellular function.
What did the Study claim compared to what their actual findings were?
[[{“type”:”media”,”view_mode”:”media_large”,”fid”:”162″,”attributes”:{“class”:”media-image alignright size-medium wp-image-4973″,”typeof”:”foaf:Image”,”style”:””,”width”:”300″,”height”:”182″,”alt”:”man2″}}]]There were many notable flaws with this study, most prominent being that it was not actually engineered to assess if fish oil led to prostate cancer. They extrapolated their results from weak evidence taken from their abandoned 2011 study called SELECT (Selenium and Vitamin E Cancer Prevention Trial). Additionally, only one blood sample was taken which measured total plasma phospholipid fatty acids; not only is this not looking at specific levels of EPA and DHA, but plasma phospholipids fluctuate with consumption of fish oil and other fats in proportion to how much and when they were taken. Therefore, the long term index of these phospholipid stores were not indicated by their methods [4]. This is further compounded by the fact that there was no record of the participants fish oil intake and the researchers assessed plasma levels of LC n-3 FA, rather than the more accurate measure of LC n-3 FA in red blood cells. Red blood cells incorporate the EPA and DHA into their membranes and provide a more reliable measure of long-term availability of LC n-3 FA for sufficient support of organs and tissues [2,4], whereas plasma LC n-3 FA levels do not.
Being that this study was not engineered to assess these fats, it follows that the researchers set absolutely no controls for participant’s individual physiology, nutrition, genetic predispositions, current health status or any other environmental toxins or experiences that could have lead to their prostate cancer. And to top off their extrapolation, they contorted the statistics in derive significance. For the study design they used, NO significance was found!
More Research
The lead researcher Brasky, claimed to have done his due diligence in supporting his publication by conducting a meta-analysis, which is when a researcher compiles numerous studies to contrast and combine their results with. Upon investigating his sources, it was revealed that his analysis consisted of only 3 sources, one of which was his own from 2011 [3].
A recent review by Zhennan et al. (2013) investigated the role LC n-3 FAs may have in reducing prostate cancer by their incorporation into and their effect on cell membrane signalling [5]. Additionally, Safarinejad et al. (2013) found significant decreases in serum Prostate-Specific Antigen (PSA) with EHA and Co-Q10 supplements, where elevated serum PSA can be associated with prostate cancer presence [6]. Furthermore, multiple meta-analyses and population based studies have shown a reduction of prostate cancer with increased LC n-3 FA intake as well as a decrease in prostate related fatalities with increased fish consumption [3]. Another meta-analysis by Zheng (2013) showed a very strong association of increased polyunsaturated fats with a lower risk of breast cancer [3].
Brasky’s claim is concerning because it may impact the welfare of consumers. Physiologically, EPA and DHA are essential and in order to sufficiently support our cellular functions and ourselves as a whole, we need to ensure sufficient intake of omega rich foods. In our clinic, we still highly encourage patients to supplement their diets and consume whole food sources of omega-3s, as these new findings do not hold enough legitimacy to displace the current state of knowledge.
If you have any questions or concerns about your omega-3 intake or prostate cancer please contact us to schedule an appointment with Dr. Gurm. Call (604) 949-0077 or email us at info@portmoodyhealth.com.
References:
1. Braskey TM, et al. Plasma Phospholipid Fatty Acids and Prostate Cancer Risk in the SELECT Trial. JNCI J Natl Cancer Inst. 2013 Jul 10; 1093.
http://jnci.oxfordjournals.org/content/early/2013/07/09/jnci.djt174.abstract
2. Schuchart JP and Hahn A. Bioavailability of long-chain omega-3 fatty acids. Prostaglandins Leukot Essent Fatty Acids. 2013 Jul 89; 1:8.
http://www.ncbi.nlm.nih.gov/pubmed/23676322
3. Global Organization for EPA and DHA Omega-3s. Omega-3s and Prostate Cancer Risk [Peer commentary on the paper “Plasma Phospholipid Fatty Acids and Prostate Cancer Risk in the SELECT Trial” by Brasky T.M. et al, 2013, JNCI, doi:10.1093/jnci/djt174.]. 2013 Jul.
http://us1.campaign-archive1.com/?u=4ae075406cd789efec4e9ff09&id=6f3dc7a018&e=e358027545
4. MacKay D, N.D. CRN Says New Study On Omega-3 Conclusions Are Overblown. Council for responsible Nutrition. 2013 Jul.
http://www.crnusa.org/CRNPR13-Omega3071113.html
5. Zhennan G, et al. Mechanisms of Omega-3 Polyunsaturated fatty Acids in Prostate Cancer Prevention . Biomed Research International 2013 May 2013;1:10.
http://www.hindawi.com/journals/bmri/2013/824563/
6. Safrainejad MR, et al. Effects of EPA, gamma-linolenic acid or coenzyme Q10 on serum prostate-specific antigen levels: a randomised, double-blind trial. Br J Nutr. 2013 Jul 110;164:171.
http://www.ncbi.nlm.nih.gov/pubmed/23199523