News headlines recently announced research suggesting a link between supplementation with Omega-3 fish oils and an increase in risk of prostate cancer.
The practice has stocked Omega-3 fatty acids for several years due to their known beneficial effects in many body systems. Obviously we are concerned about the implications of this research and await further investigations on the matter. It is always difficult to know how to advise patients when this sort of study is published but it does seem that, as yet, there are several confounding factors. Although there is a suggestion of a possible correlation, there is no evidence of a causative link and no suggestions with regard to the mechanism by which Omega 3 fatty acids may result in increased risk of prostate cancer.
Below are the comments from Nutri, our suppliers, on the 12th July:
“High levels of long chain omega-3 may increase prostate cancer risk” was the title in many international and national newspapers yesterday morning which caused concern among omega-3 Fish Oil supplement users. Extensive research has been carried out on omega-3 fatty acids and their positive benefits in relation to cardiovascular function, brain function, joint health, skin health and general health. This study, which was carried out by the Fred Hutchinson Cancer Research Centre, USA, and published in the Journal of the National Cancer Institute, was a sub trial of SELECT (Selenium and Vitamin E Cancer Prevention Trial). Using data from the SELECT study, the participants included 834 men who had been diagnosed with prostate cancer, along with a comparison group of 1,393 men selected randomly from the original 35,500 participants. Analysis of blood plasma levels concluded that long chain omega-3 PUFA overall, and DPA and DHA in particular, were associated with linear increases in prostate cancer risk.
On further investigation into the trial, there are many limitations to this study. This study only discusses a correlation and correlation does not equal causation. There is a long way to go until a cause and effect relationship between intake of oily fish and risk of prostate cancer can be indicated. In addition, this study doesn’t include any information about how omega-3 intake was achieved, whether through diet or supplementation, yet the researchers are quick to blame supplementation. The trial was lacking control as participants were asked to complete self-administered questionnaires concerning alcohol intake and smoking habit amongst other factors. No participant was asked about diet or fish oil supplementation levels. It is also unclear from the results exactly how high levels of omega-3 could increase the risk of prostate cancer.”
In a 2010 meta-analysis of 31 studies published in the American Journal of Clinical Nutrition, the risk of prostate cancer diagnosis calculated for high fish consumption ranged from 61% decrease in risk to a 77% increase in risk, and several showed no significant difference in risk at all.
Nutri Advanced confirm that this newly published study contained no evidence of causation in relation to Omega-3 fatty acids supplements and prostate cancer risk and would encourage people to continue supplementing with Omega-3 fatty acids until further research has been carried out. Omega-3 fatty acids, whether obtained from oily fish or from supplements, remain one of the safest, most researched, most beneficial elements of a healthy diet.
The practice will continue to stock and recommend Omega-3 to patients at this point in time, but we are happy to discuss this issue with patients who may have concerns.