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
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
Current version onlyHigh versus low long‐chain omega‐3 fats for preventing cardiovascular disease and mortality (primary outcomes)
Population: adults with or without existing CVD
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
All‐cause mortality – deaths High vs low long‐chain omega‐3 fats | RR 0.97 [0.93, 1.01] | 45 studies · 143693 participants | High |
Cardiovascular mortality – cardiovascular deaths High vs low long‐chain omega‐3 fats | RR 0.92 [0.86, 0.99] | 29 studies · 117837 participants | Moderate 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 participants | High |
Coronary heart disease mortality – CHD deaths High vs low long‐chain omega‐3 fats | RR 0.9 [0.81, 1] | 24 studies · 127378 participants | Low 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 participants | Low 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 participants | Moderate 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 participants | Low 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 participants | Very 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 participants | Very 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
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
All‐cause mortality – deaths High vs low alpha‐linolenic acid omega‐3 fats | RR 1.01 [0.84, 1.2] | 5 studies · 19327 participants | Moderate |
Cardiovascular mortality – cardiovascular deaths High vs low alpha‐linolenic acid omega‐3 fats | RR 0.96 [0.74, 1.25] | 4 studies · 18619 participants | Moderate 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 participants | Low 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 participants | Moderate 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 participants | Low 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 participants | Very 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 participants | Moderate Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias |
Harms: bleeding High vs low alpha‐linolenic acid omega‐3 fats | no estimate extracted | NR | No 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 participants | Very 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
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
Outcomes All in trials of 12 to 72 months' duration High vs low omega‐3 fats | no estimate extracted | NR | No studies |
Measures of adiposity, LCn3 ‐ weight, kg High vs low omega‐3 fats | no estimate extracted | 14 studies · 17000 participants | High |
Measures of adiposity, LCn3 ‐ BMI, kg/m2 High vs low omega‐3 fats | no estimate extracted | 15 studies · 15474 participants | High |
Serum total cholesterol, LCn3 – TC, mmol/L High vs low omega‐3 fats | no estimate extracted | 30 studies · 38469 participants | High |
Serum triglyceride,LCn3 ‐ fasting TG, mmol/L High vs low omega‐3 fats | no estimate extracted | 27 studies · 43998 participants | High |
Serum high‐density lipoprotein, LCn3 – HDL, mmol/L High vs low omega‐3 fats | no estimate extracted | 30 studies · 46604 participants | High |
Serum low‐density lipoprotein, LCn3 – LDL, mmol/L High vs low omega‐3 fats | no estimate extracted | 25 studies · 43454 participants | High |
Measures of adiposity, ALA – weight, kg High vs low omega‐3 fats | no estimate extracted | 4 studies · 664 participants | Very 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 extracted | 3 studies · 1581 participants | Very 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 extracted | 6 studies · 2164 participants | Low Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias |
Serum triglyceride, ALA ‐ fasting TG, mmol/L High vs low omega‐3 fats | no estimate extracted | 6 studies · 1776 participants | Moderate 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 extracted | 6 studies · 1776 participants | Moderate 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 extracted | 7 studies · 2201 participants | Moderate Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias |
High versus low LCn3 for preventing cardiovascular disease and mortality (primary outcomes)
Population: adults with or without existing CVD
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
All‐cause mortality – deaths High vs low LCn3 | RR 0.98 [0.93, 1.03] | 39 studies · 92653 participants | High |
Cardiovascular mortality – cardiovascular deaths High vs low LCn3 | RR 0.95 [0.87, 1.03] | 25 studies · 67772 participants | Moderate Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias |
Cardiovascular events – cardiovascular events High vs low LCn3 | RR 0.99 [0.94, 1.04] | 38 studies · 90378 participants | High |
Coronary heart disease mortality – CHD deaths High vs low LCn3 | RR 0.93 [0.79, 1.09] | 21 studies · 73491 participants | Moderate Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias |
Coronary heart disease events – CHD events High vs low LCn3 | RR 0.93 [0.88, 0.97] | 28 studies · 84301 participants | Moderate Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias |
Stroke High vs low LCn3 | RR 1.06 [0.96, 1.16] | 28 studies · 89358 participants | Moderate Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias |
Arrhythmias High vs low LCn3 | RR 0.97 [0.9, 1.05] | 28 studies · 53796 participants | Moderate Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias |
Harms: bleeding High vs low LCn3 | RR 1.06 [0.73, 1.52] | 8 studies · 45562 participants | Very low Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias |
Harms: pulmonary embolus or DVT High vs low LCn3 | RR 1.25 [0.41, 3.78] | 4 studies · 3011 participants | Very low Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias |
High versus low ALA omega‐3 fats for preventing cardiovascular disease (primary outcomes)
Population: adults with or without existing CVD
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
All‐cause mortality – deaths High vs low ALA omega‐3 fats | RR 1.01 [0.84, 1.2] | 5 studies · 19327 participants | Moderate |
Cardiovascular mortality – cardiovascular deaths High vs low ALA omega‐3 fats | RR 0.96 [0.74, 1.25] | 4 studies · 18619 participants | Moderate Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias |
Cardiovascular events – cardiovascular events High vs low ALA omega‐3 fats | RR 0.95 [0.83, 1.07] | 5 studies · 19327 participants | Low Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias |
Coronary heart mortality – CHD deaths High vs low ALA omega‐3 fats | RR 0.95 [0.72, 1.26] | 3 studies · 18353 participants | Moderate Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias |
Coronary Heart Disease – CHD events High vs low ALA omega‐3 fats | RR 1 [0.82, 1.22] | 4 studies · 19061 participants | Low Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias |
Stroke High vs low ALA omega‐3 fats | RR 1.15 [0.66, 2.01] | 5 studies · 19327 participants | Very low Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias |
Arrhythmias – AF, VT, VF High vs low ALA omega‐3 fats | RR 0.79 [0.57, 1.1] | 1 study · 4837 participants | Moderate Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias |
Harms: bleeding High vs low ALA omega‐3 fats | no estimate extracted | NR | No studies |
Harms: pulmonary embolus or DVT High vs low ALA omega‐3 fats | RR 0.32 [0.01, 7.8] | 1 study · 708 participants | Very low Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias |
High versus low omega‐3 fats for modification of CVD risk factors (adiposity and lipids): key outcomes
Population: adults with or without existing CVD
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
Outcomes All in trials of 12 to 72 months' duration High vs low omega‐3 fats | no estimate extracted | NR | No studies |
Measures of adiposity – LCn3 – Weight, kg High vs low omega‐3 fats | no estimate extracted | 12 studies · 15812 participants | High |
Measures of adiposity – LCn3 – BMI, kg/m2 High vs low omega‐3 fats | no estimate extracted | 14 studies · 15234 participants | High |
Serum total cholesterol – LCn3 – TC, mmol/L High vs low omega‐3 fats | no estimate extracted | 28 studies · 37281 participants | Moderate Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias |
Serum triglyceride, fasting – LCn3 – TG, mmol/L High vs low omega‐3 fats | no estimate extracted | 24 studies · 35534 participants | High |
Serum high density lipoprotein – LCn3 – HDL, mmol/L High vs low omega‐3 fats | no estimate extracted | 27 studies · 37237 participants | High |
Serum low density lipoprotein – LCn3 – LDL, mmol/L High vs low omega‐3 fats | no estimate extracted | 23 studies · 35035 participants | Moderate Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias |
Measures of adiposity – ALA – Weight, kg High vs low omega‐3 fats | no estimate extracted | 4 studies · 664 participants | Very 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 extracted | 3 studies · 1581 participants | 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 extracted | 6 studies · 2164 participants | Low Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias |
Serum Triglyceride, fasting – ALA – TG, mmol/L High vs low omega‐3 fats | no estimate extracted | 6 studies · 1776 participants | Moderate 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 extracted | 6 studies · 1776 participants | Moderate 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 extracted | 7 studies · 2201 participants | Low Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias |
High versus low LCn3 for preventing cardiovascular disease and mortality (primary outcomes)
Population: adults with or without existing CVD
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
All‐cause mortality – deaths High vs low LCn3 | RR 0.98 [0.93, 1.03] | 39 studies · 92653 participants | High |
Cardiovascular mortality – cardiovascular deaths High vs low LCn3 | RR 0.95 [0.87, 1.03] | 25 studies · 67772 participants | Moderate Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias |
Cardiovascular events – cardiovascular events High vs low LCn3 | RR 0.99 [0.94, 1.04] | 38 studies · 90378 participants | High |
Coronary heart disease mortality – CHD deaths High vs low LCn3 | RR 0.93 [0.79, 1.09] | 21 studies · 73491 participants | Moderate Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias |
Coronary heart disease events – CHD events High vs low LCn3 | RR 0.93 [0.88, 0.97] | 28 studies · 84301 participants | Moderate Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias |
Stroke High vs low LCn3 | RR 1.06 [0.96, 1.16] | 28 studies · 89358 participants | Moderate Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias |
Arrhythmias High vs low LCn3 | RR 0.97 [0.9, 1.05] | 28 studies · 53796 participants | Moderate Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias |
Harms: bleeding High vs low LCn3 | RR 1.06 [0.73, 1.52] | 8 studies · 45562 participants | Very low Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias |
Harms: pulmonary embolus or DVT High vs low LCn3 | RR 1.25 [0.41, 3.78] | 4 studies · 3011 participants | Very low Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias |
High versus low ALA omega‐3 fats for preventing cardiovascular disease (primary outcomes)
Population: adults with or without existing CVD
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
All‐cause mortality – deaths High vs low ALA omega‐3 fats | RR 1.01 [0.84, 1.2] | 5 studies · 19327 participants | Moderate |
Cardiovascular mortality – cardiovascular deaths High vs low ALA omega‐3 fats | RR 0.96 [0.74, 1.25] | 4 studies · 18619 participants | Moderate Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias |
Cardiovascular events – cardiovascular events High vs low ALA omega‐3 fats | RR 0.95 [0.83, 1.07] | 5 studies · 19327 participants | Low Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias |
Coronary heart mortality – CHD deaths High vs low ALA omega‐3 fats | RR 0.95 [0.72, 1.26] | 3 studies · 18353 participants | Moderate Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias |
Coronary Heart Disease – CHD events High vs low ALA omega‐3 fats | RR 1 [0.82, 1.22] | 4 studies · 19061 participants | Low Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias |
Stroke High vs low ALA omega‐3 fats | RR 1.15 [0.66, 2.01] | 5 studies · 19327 participants | Very low Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias |
Arrhythmias – AF, VT, VF High vs low ALA omega‐3 fats | RR 0.79 [0.57, 1.1] | 1 study · 4837 participants | Moderate Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias |
Harms: bleeding High vs low ALA omega‐3 fats | no estimate extracted | NR | No studies |
Harms: pulmonary embolus or DVT High vs low ALA omega‐3 fats | RR 0.32 [0.01, 7.8] | 1 study · 708 participants | Very low Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias |
High versus low omega‐3 fats for modification of CVD risk factors (adiposity and lipids): key outcomes
Population: adults with or without existing CVD
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
Outcomes All in trials of 12 to 72 months' duration High vs low omega‐3 fats | no estimate extracted | NR | No studies |
Measures of adiposity – LCn3 – Weight, kg High vs low omega‐3 fats | no estimate extracted | 12 studies · 15812 participants | High |
Measures of adiposity – LCn3 – BMI, kg/m2 High vs low omega‐3 fats | no estimate extracted | 14 studies · 15234 participants | High |
Serum total cholesterol – LCn3 – TC, mmol/L High vs low omega‐3 fats | no estimate extracted | 28 studies · 37281 participants | Moderate Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias |
Serum triglyceride, fasting – LCn3 – TG, mmol/L High vs low omega‐3 fats | no estimate extracted | 24 studies · 35534 participants | High |
Serum high density lipoprotein – LCn3 – HDL, mmol/L High vs low omega‐3 fats | no estimate extracted | 27 studies · 37237 participants | High |
Serum low density lipoprotein – LCn3 – LDL, mmol/L High vs low omega‐3 fats | no estimate extracted | 23 studies · 35035 participants | Moderate Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias |
Measures of adiposity – ALA – Weight, kg High vs low omega‐3 fats | no estimate extracted | 4 studies · 664 participants | Very 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 extracted | 3 studies · 1581 participants | 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 extracted | 6 studies · 2164 participants | Low Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias |
Serum Triglyceride, fasting – ALA – TG, mmol/L High vs low omega‐3 fats | no estimate extracted | 6 studies · 1776 participants | Moderate 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 extracted | 6 studies · 1776 participants | Moderate 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 extracted | 7 studies · 2201 participants | Low Downgraded: risk of bias, imprecision, inconsistency, indirectness, publication bias |