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Randomized trial · measured the question itself

3.5-year trial in 1,228 dialysis patients: fish oil lowered serious heart events

Lok and colleagues · The New England journal of medicine · 2026

Original title: Fish-Oil Supplementation and Cardiovascular Events in Patients Receiving Hemodialysis.

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What the study found

Points to benefit

Serious heart events were 0.31 vs. 0.61 per 1000 patient-days (hazard ratio, 0.57; 95% CI, 0.47 to 0.70). Fatal and nonfatal stroke: 0.37. Side effects did not differ meaningfully between groups.

The study at a glance

Type of study
Randomized trial
Who or what was studied
1,228 people · adults on long-term kidney dialysis, in 26 sites in Canada and Australia
What was tested
4 g a day of omega-3 fish oil (1.6 g EPA, 0.8 g DHA) versus corn-oil placebo, about 3.5 years
What it measured
The question itself: heart attacks, strokes and heart deaths
Daily amount
4 g a day
How long
182 weeks
Trial registration
ISRCTN00691795
Who has a stake
No disclosure in PubMed
No disclosure in PubMed. Supported by the Heart and Stroke Foundation of Canada and others.
Journal
The New England journal of medicine, 2026
Source
PubMed record 41201837. This page is based on the abstract only.

How much this study counts

  • ✓Randomized: people were put into groups by chance, so the groups start out alike.
  • ✓Compared with a placebo, a dummy treatment.
  • ✓Large: 1,228 people.
  • ✓Long: about 3.5 years.
  • ✓Measured the question itself: heart attacks, strokes and heart deaths.
  • •The PubMed record has no conflict-of-interest statement.
  • •Summarized from the PubMed abstract only. The full paper may hold details the abstract leaves out.

✓ Strength– Limit• Note

These points come from fixed rules about the type of study, its size and length, what it measured, and who has a stake. Every study on Digestery gets the same rules.

Where this study sits

Each dot is one on-topic paper on this question. Steps near the top answer the question more directly.

↑ Stronger evidence

  1. Trials in people: heart attacks, strokes and heart deaths

    11

    7 benefit, 4 no difference

    ↑ This study is the ringed dot

  2. Trials in people: other measures

    3

    1 benefit, 2 no difference

  3. Trials in people: lab tests or safety

    0

    None among the papers we read.

  4. Population studies

    0

    None among the papers we read.

  5. Blood levels and genes

    0

    None among the papers we read.

↓ Weaker evidence

  • Points to benefit
  • Mixed
  • No difference
  • No direction
  • Points to harm

How it fits with the other research

The short answer to “Does fish oil prevent heart disease?”

Little or no effect in most trials.

Confidence: moderate. Based on 21 on-topic papers.

Read the full answer

Of the other 10 papers on the same step: 6 benefit, 4 no difference. This one found benefit. It agrees with most of them.

Other papers on the same step

See all 21 studies on this question

How this page was made

Label

First read of the abstract
Claude Sonnet
Independent second read
Claude Haiku
Differences settled
The two reads agreed on every checked field. Claude Opus 5.5.
Headline
Claude Sonnet, from the checked study record. A script checked its numbers and wording.
Numbers
Checked against the abstract by a script
“How much this study counts”
Fixed rules, the same for every study
Source check by a person
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