Cochrane · systematic review · CD003177

Omega‐3 fatty acids for the primary and secondary prevention of cardiovascular disease

Abdelhamid, AS, Brown, TJ, Brainard, JS, et al. · Cochrane Database of Systematic Reviews · 2020 · Cochrane Library

Heart3 versionsAMSTAR 2: not assessed
SoF tableOnly the outcomes this review put in its Summary of Findings table are listed (the Cochrane Handbook caps them at about seven per comparison). Its other analyses are not shown here.
Questions
31
current version
GRADE rated
29
No studies
2
Included studies
NR
No studies 2 · 6.5%Ungraded 0 · 0%Very low 6 · 19.4%Low 6 · 19.4%Moderate 9 · 29%High 8 · 25.8%

Ungraded means an effect was reported without a GRADE rating; it is not a gap. No studies means the review found nothing to answer the question. The six categories are a display order, not a score.

Questions and results

Show all 3 versions

High versus low long‐chain omega‐3 fats for preventing cardiovascular disease and mortality (primary outcomes)

Population: adults with or without existing CVD
9 questions
OutcomeEffectEvidenceStatus / GRADE
All‐cause mortality – deaths
High vs low long‐chain omega‐3 fats
RR 0.97 [0.93, 1.01]45 studies · 143693 participantsHigh
Cardiovascular mortality – cardiovascular deaths
High vs low long‐chain omega‐3 fats
RR 0.92 [0.86, 0.99]29 studies · 117837 participantsModerate
Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias
Cardiovascular events
High vs low long‐chain omega‐3 fats
RR 0.96 [0.92, 1.01]43 studies · 140482 participantsHigh
Coronary heart disease mortality – CHD deaths
High vs low long‐chain omega‐3 fats
RR 0.9 [0.81, 1]24 studies · 127378 participantsLow
Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias
Coronary heart disease events – CHD events
High vs low long‐chain omega‐3 fats
RR 0.91 [0.85, 0.97]32 studies · 134116 participantsLow
Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias
Stroke
High vs low long‐chain omega‐3 fats
RR 1.02 [0.94, 1.12]31 studies · 138888 participantsModerate
Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias
Arrhythmias
High vs low long‐chain omega‐3 fats
RR 0.99 [0.92, 1.06]30 studies · 77990 participantsLow
Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias
Harms: bleeding
High vs low long‐chain omega‐3 fats
RR 1.12 [0.91, 1.37]11 studies · 80147 participantsVery low
Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias
Harms: pulmonary embolus or DVT
High vs low long‐chain omega‐3 fats
RR 1.15 [0.44, 2.98]5 studies · 3546 participantsVery low
Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias

High versus low alpha‐linolenic acid omega‐3 fats for preventing cardiovascular disease (primary outcomes)

Population: adults with or without existing CVD
9 questions
OutcomeEffectEvidenceStatus / GRADE
All‐cause mortality – deaths
High vs low alpha‐linolenic acid omega‐3 fats
RR 1.01 [0.84, 1.2]5 studies · 19327 participantsModerate
Cardiovascular mortality – cardiovascular deaths
High vs low alpha‐linolenic acid omega‐3 fats
RR 0.96 [0.74, 1.25]4 studies · 18619 participantsModerate
Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias
Cardiovascular events
High vs low alpha‐linolenic acid omega‐3 fats
RR 0.95 [0.83, 1.07]5 studies · 19327 participantsLow
Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias
Coronary heart disease mortality – CHD deaths
High vs low alpha‐linolenic acid omega‐3 fats
RR 0.95 [0.72, 1.26]3 studies · 18353 participantsModerate
Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias
Coronary heart disease events
High vs low alpha‐linolenic acid omega‐3 fats
RR 1 [0.82, 1.22]4 studies · 19061 participantsLow
Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias
Stroke
High vs low alpha‐linolenic acid omega‐3 fats
RR 1.15 [0.66, 2.01]5 studies · 19327 participantsVery low
Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias
Arrhythmias
High vs low alpha‐linolenic acid omega‐3 fats
RR 0.73 [0.55, 0.97]2 studies · 4912 participantsModerate
Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias
Harms: bleeding
High vs low alpha‐linolenic acid omega‐3 fats
no estimate extractedNRNo studies
Harms: pulmonary embolus or DVT
High vs low alpha‐linolenic acid omega‐3 fats
RR 0.32 [0.01, 7.8]1 study · 708 participantsVery low
Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias

High versus low omega‐3 fats for modification of cardiovascular disease risk factors (adiposity and lipids): key outcomes

Population: adults with or without existing CVD
13 questions
OutcomeEffectEvidenceStatus / GRADE
Outcomes All in trials of 12 to 72 months' duration
High vs low omega‐3 fats
no estimate extractedNRNo studies
Measures of adiposity, LCn3 ‐ weight, kg
High vs low omega‐3 fats
no estimate extracted14 studies · 17000 participantsHigh
Measures of adiposity, LCn3 ‐ BMI, kg/m2
High vs low omega‐3 fats
no estimate extracted15 studies · 15474 participantsHigh
Serum total cholesterol, LCn3 – TC, mmol/L
High vs low omega‐3 fats
no estimate extracted30 studies · 38469 participantsHigh
Serum triglyceride,LCn3 ‐ fasting TG, mmol/L
High vs low omega‐3 fats
no estimate extracted27 studies · 43998 participantsHigh
Serum high‐density lipoprotein, LCn3 – HDL, mmol/L
High vs low omega‐3 fats
no estimate extracted30 studies · 46604 participantsHigh
Serum low‐density lipoprotein, LCn3 – LDL, mmol/L
High vs low omega‐3 fats
no estimate extracted25 studies · 43454 participantsHigh
Measures of adiposity, ALA – weight, kg
High vs low omega‐3 fats
no estimate extracted4 studies · 664 participantsVery low
Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias
Measures of adiposity, ALA – BMI, kg/m2
High vs low omega‐3 fats
no estimate extracted3 studies · 1581 participantsVery low
Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias
Serum total cholesterol, ALA – TC, mmol/L
High vs low omega‐3 fats
no estimate extracted6 studies · 2164 participantsLow
Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias
Serum triglyceride, ALA ‐ fasting TG, mmol/L
High vs low omega‐3 fats
no estimate extracted6 studies · 1776 participantsModerate
Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias
Serum high‐density lipoprotein, ALA – HDL, mmol/L
High vs low omega‐3 fats
no estimate extracted6 studies · 1776 participantsModerate
Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias
Serum low‐density lipoprotein, ALA – LDL, mmol/L
High vs low omega‐3 fats
no estimate extracted7 studies · 2201 participantsModerate
Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias