Randomised controlled trialindependent cross-checkabstract checked★ key study I-FSH-108 in-depth review

Fish-oil-fed salmon helped heart patients more than rapeseed-oil-fed salmon

Dietary intake of differently fed salmon; the influence on markers of human atherosclerosis.

Overview

Seierstad SL et al.. Eur J Clin Invest 2005 · PMID 15638820 · DOI 10.1111/j.1365-2362.2005.01443.x

Only salmon fed fish oil lowered triglycerides and two inflammation markers compared with the other salmon groups.

Does the study support the specific claim? Partly · Methodological quality: moderate

Study explained simply

What did the researchers want to find out?: Compare differently fed salmon in heart patients.
How was the study done?: 6-week double-blind trial.
How many people, animals or samples were studied?: 60 CHD patients.
What was actually found?: Better markers with fish-oil-fed salmon.
How large was the observed effect?: P<0.05 for TG, VCAM-1, IL-6.
What do the results mean in everyday life?: Feed affects how much benefit salmon gives.
What are the study's limitations?: No no-salmon control.
What does it say about Elawady's specific claim?: Benefit may shrink, but no harm shown.
Do the results apply to Germany and Europe?: High.
What can explicitly not be concluded from this study?: That rapeseed-fed salmon causes inflammation.

Authors: Seierstad SL et al.
Journal: Eur J Clin Invest
Year: 2005
Identifier: PMID 15638820 DOI 10.1111/j.1365-2362.2005.01443.x
Verification: verified – PubMed efetch 2026-10-26; Crossref checked
Retracted: no
Corrections: none
Extent checked: abstract only
Conflicts of interest and funding: Research Support, Non-U.S. Gov't (details not in abstract)

Do salmon fed fish oil or rapeseed oil differ in their effects on markers of atherosclerosis?

Study design: Randomised controlled trial – Double-blind randomized trial, 6 weeks
Population: Patients with coronary heart disease
Country: Norway
Period: not stated in abstract
Sample size: 60
Inclusion and exclusion criteria: CHD patients

Exposure / intervention: About 700 g/week of Atlantic salmon fed 100% fish oil, 100% rapeseed oil, or 50/50
Comparator: Differently fed salmon (no no-fish control)
Endpoints: Serum fatty acids, lipids, VCAM-1, IL-6
Statistical methods: Between-group comparisons

Results: Serum fatty acids mirrored the fillets; total n-3 PUFA and the n-3/n-6 ratio increased markedly in the fish-oil group (P<0.02). 'Significant reductions of serum triglycerides and of vascular cell adhesion molecule-1 and interleukin-6 were obtained in patients receiving the FO diet when compared with the two other groups (P < 0.05 for all).'
Absolute risks: not applicable
Authors' conclusion: Salmon very high in marine n-3 PUFA gives more favourable biochemical changes in CHD patients than fillets with intermediate or low marine n-3 PUFA.

Small, 6 weeks
No no-fish control, so it cannot show whether rapeseed-fed salmon raises inflammation
Very high intake (700 g/week)

C-FSH-05: part of the marker benefit (IL-6, VCAM-1) appeared only with fish-oil-fed salmon; no evidence that rapeseed-fed salmon is pro-inflammatory.

High.

Supports 'reduced benefit' but not 'pro-inflammatory'.

Multidimensional assessment
Multidimensional assessment
Authenticity of the source	verified
Methodological quality	moderate
Risk of bias	some concerns
Precision of results	low
Directness	direct
Reproducibility	partly replicated
Consistency with the overall evidence	mixed
Regional transferability	high
Adequacy of the interpretation (by the archive)	not applicable