Fish Oil Linked To Prostate Cancer Risk: Are Men Consuming Too Much Omega-3?
Researchers at the Fred Hutchinson Research Center have just confirmed the link between high concentrations of omega-3 fatty acids and an increased risk of prostate cancer. Previously in 2011, a large study was published in the Journal of the National Cancer Institute, finding those that who consume fatty fish and fish oil supplements have a 71-percent higher risk of prostate cancer.
Who is at risk?
These findings are of great significance to the male community, considering one in six men will be diagnosed with prostate cancer at some point in their lifetime, according to the American Cancer Society. The study, which was funded by the National Cancer Institute and the National Center for Complementary and Alternative Medicine, analyzed 834 men who had been diagnosed with primary prostate cancer, of which 156 were high-grade cancer. A comparison group of 1,393 men were randomly selected from a pool of 35,500 participants, which kept results as realistic and applicable as possible.
The first study, also conducted by the Fred Hutchinson team, was published in 2011 and reported similar links to high blood concentrations of DHA with a prostate cancer risk that was more than doubled. The latest findings not only confirmed the study, but also indicated that high concentrations of EPA, DPA, and DHA were linked to the 71-percent increased risk of high-grade prostate cancer. The three concentrations are anti-inflammatory and metabolically-related fatty acids derived from fatty fish and fish oil supplements.
The National Cancer Institute estimates that in the year 2013, there will be 238,590 new prostate cancer diagnoses and about 29,720 men will die of prostate cancer in the United States alone. The increased risk that Fred Hutchinson scientists have discovered is for high-grade prostate cancer, which means tumors are more likely to be fatal. The study also revealed a 44-percent risk increase in low-grade prostate cancer and an overall 43-percent risk increase for all prostate cancers.
The prostate is a small, walnut-sized gland that sits just below the bladder and above the penis. Because the urethra runs through the center of the prostate and secretes a fluid that protects the sperm, men can experience some degree of erectile dysfunction if surgery is necessary to remove the threat of cancer. It all depends on the type of surgery, stage of cancer, and skill of the surgeon. Almost two-thirds of men that are diagnosed are 65 or older.
Prostate cancer is the second leading cause of cancer death for men in the United States, with lung cancer as number one.
"What's important is that we have been able to replicate our findings from 2011 and we have confirmed that marine omega-3 fatty acids play a role in prostate cancer occurrence," said Theodore Brasky, Ph.D., a research assistant professor at The Ohio State University Comprehensive Cancer Center, who was also a postdoctorate candidate at Fred Hutchinson while the research was being conducted.
What are omega-3 fatty acids?
One particularly harmful effect of omega-3 fatty acids is their ability to convert into compounds that can cause cellular damage, as well as their role in immunosuppression, which is the act of reducing immune system response, also a known side effect of chemotherapy.
Unfortunately for men, because of these findings, omega-3 fatty acids should be avoided — at least until new research says otherwise.
"We've shown once again that the use of nutritional supplements may be harmful," said Alan Kristal, Ph.D., the paper's senior author and member of the Fred Hutchinson Public Health Sciences Division. Kristal said the findings in both the 2011 and new 2013 study were surprising because omega-3 fatty acids were famously known for their health benefits based on anti-inflammatory properties.