Omega-3s and Prostate Cancer: Benefits Outweigh The Risks
Surprising study results show that men with high blood levels of heart-healthy Omega-3 fatty acid actually have a much greater risk for developing aggressive prostate cancer. These findings were the exact opposite of what researchers had expected, leading experts to question their understanding of this disease process and what can be done to reduce one's risk for prostate cancer development.
Good for the Heart, Not for the Prostate
This study, conducted by researchers at Fred Hutchinson Cancer Research Center in Seattle analyzed data from over 3,400 men. They examined blood levels of Omega-3 fatty acid, also known as DHEA, as well as Omega-6 fatty acids and trans-fats. Omega-3s are considered the “good” fats and are found in fish and nuts. They have been well researched and proven to reduce inflammation, which is a contributing factor to several types of cancers. Omega-6 and trans-fats on the other hand, are found in vegetable oils and processed foods and have a high association with heart disease and increased amounts of inflammation.
"We wanted to test the hypothesis that the concentrations of these fats in blood would be associated with prostate cancer risk,” said Theodore M. Brasky, Ph.D. “Specifically, we thought that omega-3 fatty acids would reduce and omega-6 and trans-fatty acids would increase prostate cancer risk."
However, what the researchers found was that the men with the highest blood levels of Omega-3 were actually 2.5 times more likely to develop aggressive prostate cancer than those with the lowest levels. Furthermore, those with the highest levels of trans-fats had a 50 percent reduction in prostate cancer risk. Omega-6 levels were not found to have any effect on the disease whatsoever.
“We were stunned to see these results and we spent a lot of time making sure the analyses were correct," said Brasky. "Our findings turn what we know — or rather what we think we know — about diet, inflammation and the development of prostate cancer on its head and shine a light on the complexity of studying the association between nutrition and the risk of various chronic diseases."
1 in 6 Men Diagnosed with Prostate Cancer
Prostate cancer is a disease which forms in the prostate gland located below the bladder in the male reproductive system. It is estimated that 1 in 6 men will be diagnosed with prostate cancer in their lifetime and it is the third leading cause of cancer death in men. Risk factors for the development of prostate cancer include being 50 years of age or older, having a family history of cancer, use of testosterone replacement therapy, smoking, and a sedentary lifestyle. Treatment generally depends on the aggressiveness of the disease and may include chemotherapy, radiation, surgery, or medication.
Study participants were a part of a larger research undertaking called the Prostate Cancer Prevention Trial which includes over 19,000 men over the age of 55. Most of the men in this study were not taking Omega-3 fish oil supplements and received their daily intake from dietary sources.
As intriguing as the study results are, Brasky warns against jumping to conclusions about the effects of fish oil on prostate cancer. He agrees that more research is needed to understand the complexity of prostate cancer and how one's diet may affect the development of the disease. Omega-3 intake has been well studied and has proven health benefits including protection against heart disease, cognitive decline, arthritis, and many other adverse health events.
Therefore the study authors say that men should continue to intake 450 mg of Omega-3's per day, which are the dietary recommendations set by most health care providers.
"Overall, the beneficial effects of eating fish to prevent heart disease outweigh any harm related to prostate cancer risk," Brasky said.
These study's findings are published in the April 25, 2011 online edition of the American Journal of Epidemiology.