Daily fish oil supplements may help lower the risk of serious cardiovascular complications in people with kidney failure and undergoing dialysis. The findings come from a large-scale international clinical trial co-led in Australia by Monash Health and Monash University’s Faculty of Clinical Sciences.
The study, known as the PISCES trial, included 1,228 participants receiving dialysis treatment at 26 centers in Australia and Canada. The results were presented at American Society of Nephrology Kidney Week 2025. New England Medical Journal.
Large clinical trial showed 43% reduction in serious cardiac events
Participants who took 4 grams of fish oil daily had significantly fewer major cardiovascular events than those who took a placebo. This supplement contained the omega-3 fatty acids EPA and DHA, which are naturally found in fish oil.
Overall, the group taking fish oil had a 43% lower rate of serious cardiovascular events. These include heart attack, stroke, cardiac death, and blood vessel-related amputations.
Adjunct Professor Kevan Polkinghorne, a nephrologist and adjunct professor in the School of Clinical Sciences at Monash Health, led the Australian portion of the trial.
“Patients on dialysis are at extremely high cardiovascular risk, but there are few treatments available to reduce that risk,” Professor Polkinghorne said. “This is an important finding in a field where many trials have yielded negative results.
“Dialysis patients typically have much lower levels of EPA and DHA than the general population. This may help explain the magnitude of the benefit observed in this group.”
Findings apply particularly to hemodialysis patients
Professor Polkinghorne stressed that the results apply particularly to people with kidney failure who are undergoing hemodialysis. He noted that the findings should not be generalized to healthy people or other patient groups.
The Australian part of this study was supported by the National Health and Medical Research Council (NHMRC). Trial coordination was managed by the Australian Kidney Trials Network (AKTN). Around 200 people from Australia took part in the study, including 44 who were treated at Monash Health.
International leadership for the PISCES trial was provided by Professor Charmaine Lok and colleagues at the University of Toronto Health Network and the University of Calgary.
