In early July 2013, a study was published in the Journal of the National Cancer Institute that showed higher levels of the Omega-3 fatty acid DHA in men having prostate cancer than in a comparable group of men who did not have prostate cancer. DHA is found in fish and fish oil supplements.
The news media reported these findings in such manner as to suggest that Omega-3 fatty acids may increase the risk for developing prostate cancer. A number of news reports strongly suggested the use of fish oil supplements as causing a higher risk for prostate cancer.
I have personally studied the research paper that led to the media reports about Omega-3 and prostate cancer. This research paper is available at http://aje.oxfordjournals.org/content/173/12/1429.full.
This was not a double blind study where a group of men taking fish oil supplements or eating fish were compared to a group of men taking a fake fish supplement (placebo) or not eating fish. This study did not account for fish oil supplementation or for level of fish consumption among the participants in the study. Eating of fish or taking fish oil supplements was not considered or used as a factor in this study.
All this study did was measure blood levels of Omega-3 fatty acids in a group of men that had prostate cancer and in a group of men that did not have prostate cancer. In so doing, the researchers found that men with prostate cancer had a higher level of the Omega-3 fatty acid DHA than those men who did not have prostate cancer.
This was an observational study. It showed there was a correlation between higher levels of DHA and the presence of prostate cancer. It must be noted, however, that correlation does not equate with causation. Just because there is a correlation between two events doesn’t mean the one event caused the other. Nothing in this study shows that DHA or any other Omega-3 fatty acid causes prostate cancer. This fact has been pointed out by numerous health professionals who have reviewed this research. Therefore, the media’s implication that Omega- 3 supplements cause prostate cancer is without merit and represents poor journalism.
Besides DHA, which is a critical fatty acid for proper brain function, fish oils also contain the very important anti-inflammatory Omega-3 fatty acid called EPA. It is to be noted that higher levels of EPA were not present in those men diagnosed with prostate cancer. Therefore, EPA was not seen as being associated with prostate cancer in this study.
While the study under consideration did show higher levels of DHA in the blood of those with prostate cancer, it is not known why this was the case and what if any role these higher levels of DHA had relative to the presence of prostate cancer. Since the cause of cancer can be multifaceted, other dynamics such as diet, stress, smoking, drug and alcohol use, medications and genetic factors all need to be considered and factored in as well. There needs to be research into how DHA could raise the risk of prostate cancer if indeed it is somehow involved in promoting such cancer.
As already stated, correlation does not equal causation. Elevated DHA levels may have nothing directly to do with the occurrence of prostate cancer but instead is a consequence of other factors responsible for the prostate cancer. A good illustration of correlation not equating with causation is provided by nutritionist Jonny Bowden. He points out that people with yellowing of the fingers tend to have higher rates of lung cancer. The yellow fingers don’t cause lung cancer but are a consequence of years of smoking where it is the smoking that causes both the yellowing of the fingers and the lung cancer.
There are thousands of studies that have been done showing the need for and the benefits of ingesting the Omega-3 fatty acids. Many of these studies have not just been observational as is the case with the study under consideration, but they are often double blind, placebo based studies providing a high level of evidence for the benefits of ingesting the Omega-3 fatty acids. These long chain fatty acids have been found to reduce inflammation, promote cardiovascular health, improve cognitive function and enhance immune response in the body. Some of the studies that have been done with Omegas-3’s have shown them to reduce the incidence of prostate cancer.
It needs to be noted that the Japanese, who are the largest consumers of fish in world, have one of the lowest rates in the world of both the occurrence of prostate cancer and death from prostate cancer. If the Omega-3 fatty acid DHA, prevalent in many of the fish the Japanese eat, promotes prostate cancer, then the Japanese men should be having an epidemic of prostate cancer.
In view of the great amount of research showing the benefits of ingesting DHA, EPA and other omega-3 fatty acids, it is prudent to continue ingesting these fatty acids by eating fish and taking fish oil supplements. When taking fish oil supplements, it is important to take high quality products. Mass market fish oil products are often highly processed and may not be utilized by the body in the manner desired. At Milk ‘N Honey, we carry high quality fish oil products that have been demonstrated to benefit the body. One such product is WholeMega from the company New Chapter.