A daily fish oil supplement slashed serious heart risks in dialysis patients

A large international study has found that taking a daily fish oil supplement can sharply lower the risk of serious heart-related complications in people undergoing dialysis for kidney failure. The research was co-led in Australia by Monash Health and the School of Clinical Sciences at Monash University.

The study, known as the PISCES trial, followed 1,228 participants receiving dialysis at 26 sites across Australia and Canada. The findings were unveiled at the American Society of Nephrology Kidney Week 2025 and released at the same time in The New England Journal of Medicine.

Fewer Heart Attacks, Strokes, and Cardiac Deaths

Participants who took four grams of fish oil each day showed striking improvements. The supplement contained the natural omega-3 fatty acids EPA and DHA. Compared with those given a placebo, these patients experienced a 43 percent reduction in serious cardiovascular events. The outcomes measured included heart attacks, strokes, cardiac-related deaths, and vascular related amputations.

Adjunct Professor Kevan Polkinghorne, a nephrologist at Monash Health and adjunct in the School of Clinical Sciences, led the Australian portion of the trial.

“Patients on dialysis have extremely high cardiovascular risk, and very few therapies have been shown to reduce that risk,” Professor Polkinghorne said. “In a field where many trials have been negative, this is a significant finding.

“Dialysis patients typically have much lower levels of EPA and DHA than the general population. This may help explain the magnitude of benefit observed in this group.”

Findings Apply Only to Dialysis Patients

Professor Polkinghorne emphasized that the results are specific to people receiving hemodialysis for kidney failure. He cautioned that the findings should not be extended to healthy individuals or other patient populations.