Randomised controlled trialcited by the Tayebat archiveabstract only checked A-SUP-09 standard review
ASCEND: fish oil in diabetes
Effects of n-3 Fatty Acid Supplements in Diabetes Mellitus.
Overview
ASCEND Study Collaborative Group et al.. N Engl J Med 2018 · PMID 30146932 · DOI 10.1056/NEJMoa1804989
No reduction in serious vascular events.
Does the study support the specific claim? Yes · Methodological quality: high
Plain-language summary
Study explained simply
- What did the researchers want to find out?
Diabetes prevention.
- How was the study done?
RCT.
- How many people, animals or samples were studied?
15,480.
- What was actually found?
Null.
- How large was the observed effect?
RR 0.97.
- What do the results mean in everyday life?
Not useful.
- What does it say about Elawady's specific claim?
Supports.
- Do the results apply to Germany and Europe?
UK.
Scientific in-depth review
1. Full reference
- Authors
- ASCEND Study Collaborative Group, Bowman L, Mafham M, Wallendszus K, Stevens W, Buck G, Barton J, Murphy K, Aung T, Haynes R, Cox J, Murawska A, Young A, Lay M, Chen F, Sammons E, Waters E, Adler A, Bodansky J, Farmer A, McPherson R, Neil A, Simpson D, Peto R, Baigent C, Collins R, Parish S, Armitage J
- Journal
- N Engl J Med
- Year
- 2018
- Identifier
- PMID 30146932 DOI 10.1056/NEJMoa1804989
- Verification
- verified – PubMed E-utilities efetch, 2026-10-25
- Retracted
- no
- Corrections
- none
- Extent checked
- abstract only
- Conflicts of interest and funding
not stated in abstract; grants: British Heart Foundation, Medical Research Council
2. Research question
Do n-3 supplements prevent vascular events in diabetes?
3. Study design and population
- Study design
- Randomised controlled trial – Randomised placebo-controlled trial (ASCEND)
- Population
Diabetes without ASCVD
- Country
UK
- Period
mean 7.4 years
- Sample size
15,480
- Inclusion and exclusion criteria
see abstract
4. Methods and endpoints
- Exposure / intervention
1 g n-3 daily
- Comparator
Olive-oil placebo
- Endpoints
Serious vascular event
- Statistical methods
Rate ratios
5. Actual results
- Results
Serious vascular event 8.9% vs 9.2%, RR 0.97 (0.87–1.08); death RR 0.95 (0.86–1.05).
- Absolute risks
not reported in abstract
- Authors' conclusion
No significant difference in serious vascular events.
6. Strengths
- Large, long RCT
7. Weaknesses
- Olive-oil placebo
8. Risk of bias
- Orienting tool
- RoB 2
- Type of assessment
- simplified assessment (abstract only)
- Full formal assessment
- no
- Overall risk of bias
- low
- Rationale
Simplified RoB 2.
9. Assessment of the statistical interpretation
See results.
10. Relevance to the specific claim
11. Independent contrary findings
12. Transferability to Germany and Europe
High: biology and trial populations comparable to European adults.
13. Overall methodological judgement
Null RCT.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | high |
| Risk of bias | low |
| Precision of results | high |
| Directness | direct |
| Reproducibility | replicated |
| Consistency with the overall evidence | consistent |
| Regional transferability | high |
| Adequacy of the interpretation (by the archive) | correctly reported |
14. Open questions
15. Linked fact checks
- When popular oral supplements (calcium, beta-carotene, vitamin E, omega-3, multivitamins, glucosamine, selenium, vitamin A) were tested in large long-term placebo-controlled trials, most failed to deliver the promised prevention of disease. – Studies supporting the claim
- Omega-3 capsules do not prevent cardiovascular disease and increase the risk of atrial fibrillation; Elawady rejects omega-3 capsules. – Studies supporting the claim
Use by the Tayebat archive
Note: according to the archive, the studies were compiled by the archive operators. Whether Dr. Elawady himself cited this study is not established.
- What the archive says about the study
Listed in the archive bibliography of the oral-supplements rule without its own interpretation; used implicitly to support the rule summary that supplements 'failed or caused harm' in large trials.
- A. What was actually studied?
Do n-3 supplements prevent vascular events in diabetes?
- B. What did the authors find?
Serious vascular event 8.9% vs 9.2%, RR 0.97 (0.87–1.08); death RR 0.95 (0.86–1.05).
- C. What conclusions do the authors themselves draw?
No significant difference in serious vascular events.
- D. What does the archive derive from it?
Supports.
- E. Is this derivation scientifically justified?
Yes.
- Adequacy of the interpretation (by the archive)
- correctly reported