July 11, 2013
Prostate Cancer Risk Associated With Intake Of Omega-3 Fatty Acids
Lee Rannals for redOrbit.com - Your Universe Online
Researchers found that high concentrations of EPA, DPA and DHA, three anti-inflammatory and metabolically related fatty acids, are associated with a 71 percent increased risk of high-grade prostate cancer. The study also found a 44 percent increase in the risk of low-grade prostate cancer and an overall 43 percent increased risk for all prostate cancers.
The findings confirm a 2011 study that reported a similar link between high blood concentrations of DHA and a more than doubling of the risk of developing high-grade prostate cancer. The latest study also confirms results from a larger European study.
"The consistency of these findings suggests that these fatty acids are involved in prostate tumorigenesis and recommendations to increase long-chain omega-3 fatty acid intake, in particular through supplementation, should consider its potential risks," the authors wrote in the journal.
Alan Kristal, DrPH, the paper's senior author and member of the Fred Hutch Public Health Sciences Division, said that they have once again shown that the use of nutritional supplements may be harmful. He said a recent analysis published in JAMA questioned the benefit of omega-3 supplementation for cardiovascular diseases.
"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 corresponding author Theodore Brasky, PhD, a research assistant professor at The Ohio State University Comprehensive Cancer Center, who was a postdoctoral trainee at Fred Hutch when the research was conducted. "It's important to note, however, that these results do not address the question of whether omega-3's play a detrimental role in prostate cancer prognosis," he said.
Kirstal said the findings from both studies were surprising because omega-3 fatty acids are believed to have positive health effects based on their anti-inflammatory properties. Inflammation plays a role in the development and growth of several cancers.
The authors said it is unclear from this study why high levels of omega-3 fatty acids would increase prostate cancer risk. However, the fact that the findings were replicated in two large studies indicates the need for further research into possible mechanisms.
According to Kristal, the difference in blood concentrations of omega-3 fatty acids between the lowest and highest risk groups was about 2.5 percentage points, which is larger than the effect of eating salmon twice a week.