Table 1.
Subgroup Analysis of Plant-Based Dietary Patterns and Risks of Incident Type 2 Diabetes, Cardiovascular Disease, Cancer, and Mortality
| Characteristics | Study estimates, No. | Relative Risk (95% CI) | |||
|---|---|---|---|---|---|
| Inverse-Variance Fixed-Effects Meta-analysis |
Random-Effects Meta-analysis |
I2, % | P value for Heterogeneity Between Subgroups | ||
| Type 2 diabetes | |||||
| Main estimate | 22 | 0.84 (0.81–0.86) | 0.81 (0.77–0.86) | 59.7 | |
| Age, y | 0.56 | ||||
| <55 | 11 | 0.81 (0.78–0.85) | 0.79 (0.73–0.87) | 68.7 | |
| ≥55 | 11 | 0.85 (0.82–0.89) | 0.84 (0.79–0.89) | 42.0 | |
| Sex | 0.48 | ||||
| Studies among males only | 2 | 0.81 (0.72–0.90) | 0.79 (0.63–0.99) | 75.4 | |
| Studies among females only | 6 | 0.86 (0.82–0.89) | 0.85 (0.79–0.91) | 64.8 | |
| Studies among males and females | 14 | 0.82 (0.78–0.86) | 0.81 (0.77–0.86) | 58.3 | |
| BMI, kg/m2 | 0.90 | ||||
| <25 | 11 | 0.83 (0.79–0.86) | 0.81 (0.75–0.88) | 67.8 | |
| ≥25 | 11 | 0.84 (0.81–0.88) | 0.82 (0.76–0.87) | 51.8 | |
| Region | 0.87 | ||||
| North America | 12 | 0.85 (0.82–0.89) | 0.82 (0.76–0.88) | 60.1 | |
| Europe | 4 | 0.78 (0.72–0.84) | 0.79 (0.71–0.87) | 43.5 | |
| Asia/Australia | 6 | 0.83 (0.79–0.88) | 0.82 (0.73–0.91) | 66.4 | |
| Dietary pattern classification | 0.048 | ||||
| Vegan or vegetarian diets | 5 | 0.75 (0.67–0.84) | 0.63 (0.47–0.84) | 77.4 | |
| A priori-defined PDI | 17 | 0.84 (0.82–0.87) | 0.83 (0.80–0.87) | 48.3 | |
| Follow-up duration, y | 0.22 | ||||
| <15 | 11 | 0.81 (0.77–0.86) | 0.76 (0.68–0.84) | 66.3 | |
| ≥15 | 11 | 0.84 (0.81–0.86) | 0.84 (0.79–0.88) | 51.5 | |
| Cardiovascular disease | |||||
| Main estimate | 23 | 0.90 (0.87–0.92) | 0.89 (0.85–0.94) | 51.0 | |
| Age, y | 0.88 | ||||
| <55 | 16 | 0.89 (0.85–0.93) | 0.87 (0.80–0.96) | 63.8 | |
| ≥55 | 7 | 0.90 (0.87–0.93) | 0.89 (0.85–0.93) | 0 | |
| Sex | 0.68 | ||||
| Studies among males only | 3 | 0.94 (0.85–1.04) | 0.94 (0.85–1.04) | 0 | |
| Studies among females only | 6 | 0.90 (0.85–0.94) | 0.90 (0.85–0.94) | 0 | |
| Studies among males and females | 14 | 0.89 (0.86–0.93) | 0.86 (0.79–0.97) | 68.1 | |
| BMI, kg/m2 | 0.76 | ||||
| <25 | 7 | 0.91 (0.85–0.98) | 0.87 (0.72–1.05) | 77.9 | |
| ≥25 | 12 | 0.90 (0.87–0.93) | 0.90 (0.87–0.93) | 0 | |
| Region | 0.02 | ||||
| North America | 14 | 0.89 (0.86–0.93) | 0.89 (0.85–0.94) | 16.2 | |
| Europe | 7 | 0.91 (0.87–0.95) | 0.91 (0.83-1.00) | 71.5 | |
| Asia/Australia | 2 | 0.52 (0.35–0.76) | 0.52 (0.35–0.76) | 0 | |
| Dietary classification | 0.99 | ||||
| Vegan or vegetarian diets | 5 | 0.90 (0.86–0.95) | 0.85 (0.70–1.03) | 85.0 | |
| A priori-defined PDI | 18 | 0.90 (0.87–0.93) | 0.90 (0.86–0.93) | 6.1 | |
| Follow-up duration, y | 0.45 | ||||
| <15 | 8 | 0.91 (0.87–0.95) | 0.86 (0.77–0.96) | 46.0 | |
| ≥15 | 15 | 0.89 (0.86–0.93) | 0.90 (0.85–0.96) | 55.9 | |
| Cancer | |||||
| Main estimate | 32 | 0.90 (0.87–0.92) | 0.88 (0.85–0.92) | 29.0 | |
| Age, y | 0.86 | ||||
| <55 | 14 | 0.88 (0.85–0.92) | 0.88 (0.85–0.92) | 0 | |
| ≥55 | 16 | 0.91 (0.87–0.94) | 0.88 (0.82–0.94) | 50.2 | |
| Sex | 0.40 | ||||
| Studies among males only | 5 | 0.89 (0.84–0.95) | 0.83 (0.70–0.98) | 75.3 | |
| Studies among females only | 12 | 0.90 (0.86–0.94) | 0.90 (0.86–0.94) | 0 | |
| Studies among males and females | 15 | 0.89 (0.86–0.93) | 0.87 (0.82–0.92) | 18.5 | |
| BMI, kg/m2 | 0.51 | ||||
| <25 | 12 | 0.90 (0.87–0.94) | 0.90 (0.87–0.94) | 0 | |
| ≥25 | 19 | 0.89 (0.86–0.93) | 0.87 (0.81–0.92) | 41.0 | |
| Region | 0.39 | ||||
| North America | 20 | 0.89 (0.85–0.92) | 0.86 (0.81–0.91) | 47.7 | |
| Europe | 12 | 0.91 (0.87–0.95) | 0.91 (0.86–0.95) | 0 | |
| Asia/Australia | |||||
| Dietary classification | 0.14 | ||||
| Vegan or vegetarian diets | 16 | 0.85 (0.80–0.91) | 0.85 (0.80–0.91) | 0 | |
| A priori-defined PDI | 16 | 0.91 (0.88–0.93) | 0.90 (0.85–0.94) | 43.0 | |
| Follow-up duration, y | 0.98 | ||||
| <15 | 15 | 0.90 (0.86–0.94) | 0.87 (0.81–0.94) | 38.2 | |
| ≥15 | 17 | 0.89 (0.86–0.93) | 0.88 (0.84–0.93) | 23.4 | |
| Mortality | |||||
| Main estimate | 32 | 0.86 (0.84–0.87) | 0.85 (0.79–0.91) | 94.6 | |
| Age, y | 0.77 | ||||
| <55 | 17 | 0.87 (0.85–0.88) | 0.88 (0.80–0.96) | 95.9 | |
| ≥55 | 12 | 0.88 (0.85–0.90) | 0.86 (0.80–0.94) | 83.9 | |
| Sex | 0.66 | ||||
| Studies among males only | 3 | 0.94 (0.91–0.97) | 0.92 (0.86–0.99) | 66.4 | |
| Studies among females only | 3 | 0.85 (0.82–0.88) | 0.90 (0.77–1.04) | 91.6 | |
| Studies among males and females | 26 | 0.83 (0.82–0.85) | 0.83 (0.76–0.91) | 95.5 | |
| BMI, kg/m2 | 0.24 | ||||
| <25 | 12 | 0.89 (0.87–0.91) | 0.90 (0.84–0.95) | 86.6 | |
| ≥25 | 11 | 0.83 (0.80–0.86) | 0.84 (0.77–0.92) | 77.0 | |
| Region | 0.56 | ||||
| North America | 13 | 0.89 (0.87–0.90) | 0.87 (0.81–0.94) | 92.6 | |
| Europe | 14 | 0.75 (0.73–0.78) | 0.80 (0.67–0.96) | 96.4 | |
| Asia/Australia | 5 | 0.88 (0.84–0.92) | 0.86 (0.76–0.97) | 80.9 | |
| Dietary classification | 0.90 | ||||
| Vegan or vegetarian diets | 14 | 0.76 (0.74–0.78) | 0.86 (0.73–1.01) | 96.4 | |
| A priori-defined PDI | 18 | 0.89 (0.87–0.90) | 0.85 (0.80–0.91) | 90.6 | |
| Follow-up duration, y | 0.16 | ||||
| <15 | 20 | 0.80 (0.78–0.82) | 0.81 (0.74–0.89) | 91.2 | |
| ≥15 | 12 | 0.88 (0.87–0.90) | 0.90 (0.80-1.00) | 97.1 | |