New research in Seattle supports a surprising link between a common health supplement and a dramatically increased risk of prostate cancer. It's omega-3 fatty acids, derived from fatty fish and fish oil supplements.
People take it because it's supposedly heart healthy.
"I think there's a general belief that taking omega-3 fatty acids are good for you, however a study was published two years ago that combined all of the data from all of the clinical trials that looked at it, which found absolutely no effect. (It) surprised me," said Alan Kristal, Dr.P.H. at the Fred Hutchinson Cancer Research Center in Seattle.
Kristal said the findings, just published in the Journal of the National Cancer Institute, linking omega-3 fatty acids to prostate cancer, back up findings from a large European study and a similar study at FHCRC that was published in 2011.
"Two years ago, we published the findings with a caveat saying that we don't understand why this could be, it's counter to what we expected, and it's really important to replicate it to see if it's true or not," Kristal explained.
The new findings show that high concentrations of omega-3 fatty acids are associated with a 71 percent increase in the risk of high-grade prostate cancer, which Kristal explains is the type of prostate cancer that's serious and does kill you. In addition, the study showed a 45 percent increase in risk of low-grade disease, and an overall 43 percent increase in risk for all prostate cancers.
Those are big numbers, but a big unknown is why the risk?
Still, Kristal says it's time to stop taking omega-3 fatty acid supplements, lacking proof of any benefit and now with evidence of harm.
"To my mind, it's consistent with the body of evidence showing that high levels of micro-nutrients are really bad for you," concluded Kristal. Admittedly, Kristal is no fan of vitamins and the supplement industry, but a clinical trial is underway that could confirm the link between fish oil supplements and prostate cancer.
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