Scientists at Fred Hutchinson Cancer Research Center have confirmed previous findings that high levels of fatty acids from fish oil and fatty fish are associated with a 71 percent increased risk of high-grade prostrate cancer.
The study, published in the online editions of the Journal of the National Cancer Institute, validates findings by the same team in 2011 that linked high blood concentrations of omega-3 fatty acids and a higher risk for prostate cancer in men.
“We’ve shown once again that use of nutritional supplements may be harmful,” said Alan Kristal, Dr.P.H., the paper’s senior author and member of the Fred Hutch Public Health Sciences Division.
Tumors from high-grade prostate cancer are more likely to be fatal.
The new study also found a 44 percent increase in low-grade prostate cancer.
“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,” said corresponding author Theodore Brasky, Ph.D. Brasky was a postdoctoral trainee at Fred Hutch when the research took place.
The benefit of omega-3 supplementation for cardiovascular diseases like heart attacks or strokes was also questioned in a recent analysis in the Journal of the American Medical Association.
Researchers were not able explain why high levels of omega-3 fatty acids would increase prostrate cancer risk, but they called for more research.
The study analyzed the blood of 834 men who developed prostate cancer along with a comparison group of 1,393 men who did not.
The highest and lowest risk groups had a difference in blood concentrations of omega-3 fatty acids of 2.5 percentage points -- slightly more than the effect of eating salmon twice a week.
Scientists and researchers from the University of Texas, University of Washington, National cancer Institute and the Cleveland Clinic also participated in the study.
The study was funded by the National Cancer Institute and the National Center for Complementary and Alternative Medicine.