Summary of meta-analyses of RCTs and prospective cohort studies
| Studies examined | Studies | People | Measure | Fat | Risk ratio | Conclusion | |
|---|---|---|---|---|---|---|---|
| Skeaff and Miller (2009)53 | Prospective cohort studies and RCTs | 28 | 280 000 | CHD mortality | Total fat | 0.94 (0.74 to 1.18) | No significant difference |
| CHD events | Total fat | 0.93 (0.84 to 1.03) | No significant difference | ||||
| Siri-Tarino et al (2010)52 | Prospective cohort studies | 21 | 347 747 | CHD fatal and non-fatal | Saturated fat (extreme quintiles) | 1.07 (0.96 to 1.19) | No significant difference |
| CVD fatal and non-fatal | Saturated fat (extreme quintiles) | 1.00 (0.89 to 1.11) | No significant difference | ||||
| Mozaffarian et al (2010)51 | RCTs | 8 | 13 614 | CHD events | Replacing SFA with PUFA | 0.81 (0.70 to 0.95) | Significant difference |
| Hooper et al (2011)50 | RCTs | 21 | 71 790 | Total mortality | All RCTs | 0.98 (0.93 to 1.04) | No significant difference |
| Modified fat | 1.02 (0.88 to 1.18) | No significant difference | |||||
| Reduced fat | 0.97 (0.90 to 1.04) | No significant difference | |||||
| Reduced and modified fat | 0.97 (0.76 to 1.23) | No significant difference | |||||
| CVD mortality | All RCTs | 0.94 (0.85 to 1.04) | No significant difference | ||||
| Modified fat | 0.92 (0.73 to 1.15) | No significant difference | |||||
| Reduced fat | 0.96 (0.82 to 1.13) | No significant difference | |||||
| Reduced and modified fat | 0.98 (0.76 to 1.27) | No significant difference | |||||
| CVD events | All RCTs | 0.86 (0.77 to 0.96) | Significant difference | ||||
| Modified fat | 0.82 (0.66 to 1.02) | No significant difference | |||||
| Reduced fat | 0.97 (0.87 to 1.08) | No significant difference | |||||
| Reduced and modified fat | 0.77 (0.57 to 1.03) | No significant difference | |||||
| Chowdhury et al (2014)54 | Prospective cohort studies and RCTs | 32 | 530 525 | Coronary disease (All top vs bottom third) | Saturated fat | 1.02 (0.97 to 1.07) | No significant difference |
| Monounsaturated fat | 0.99 (0.89 to 1.09) | No significant difference | |||||
| Polyunsaturated fat | 0.93 (0.84 to 1.02) | No significant difference | |||||
| Trans fat | 1.16 (1.06 to 1.27) | Significant difference | |||||
| Schwingshackl and Hoffman (2014)49 | RCTs | 12 | 7150 | All-cause mortality | Modified fat intake | 0.92 (0.68 to 1.25) | No significant difference |
| CVD mortality | Modified fat intake | 0.96 (0.65 to 1.42) | No significant difference | ||||
| CVD events | Modified fat intake | 0.85 (0.63 to 1.15) | No significant difference | ||||
| MIs | Modified fat intake | 0.76 (0.54 to 1.09) | No significant difference | ||||
| All-cause mortality | Reduced fat intake | 0.79 (0.42 to 1.48) | No significant difference | ||||
| CVD mortality | Reduced fat intake | 0.93 (0.66 to 1.31) | No significant difference | ||||
| CVD events | Reduced fat intake | 0.93 (0.65 to 1.34) | No significant difference | ||||
| MIs | Reduced fat intake | 1.18 (0.88 to 1.59) | No significant difference | ||||
| Harcombe et al (2015)15 | RCTs to 1977/1983 | 6 | 2467 | All-cause mortality | Reduced or modified fat | 0.99 (0.87 to 1.15) | No significant difference |
| CHD mortality | Reduced or modified fat | 0.99 (0.78 to 1.25) | No significant difference | ||||
| Hooper et al (2015)55 | RCTs | 12 | 55 858 | Total mortality | Reduced saturated fat | 0.97 (0.90 to 1.05) | No significant difference |
| CHD mortality | Reduced saturated fat | 0.95 (0.80 to 1.12) | No significant difference | ||||
| CVD events | Reduced saturated fat | 0.83 (0.72 to 0.96) | Significant difference | ||||
| MIs | Reduced saturated fat | 0.90 (0.80 to 1.01) | No significant difference | ||||
| Non-fatal MIs | Reduced saturated fat | 0.95 (0.80 to 1.13) | No significant difference | ||||
| Stroke | Reduced saturated fat | 1.00 (0.89 to 1.12) | No significant difference | ||||
| CHD mortality | Reduced saturated fat | 0.98 (0.84 to 1.15) | No significant difference | ||||
| CHD events | Reduced saturated fat | 0.87 (0.74 to 1.03) | No significant difference |
All studies examined data available at the time of the meta-analysis other than Harcombe et al, which examined data available to the dietary committees.
CHD, coronary heart disease; CVD, cardiovascular disease; MIs, myocardial infarctions; PUFA, polyunsaturated fatty acids; RCT, randomised controlled trial; SFA, saturated fatty acids.