TABLE 2.
Odds ratios (95% CI) of developing cognitive impairment by quartiles of plant‐based diet indices among the participants with follow‐up surveys, and with normal cognition at baseline (n = 6136)
| Diet indices | N (median) a | MMSE (mean) a | Model 1 | Model 2 | Model 3 | |||
|---|---|---|---|---|---|---|---|---|
| OR (95% CI) | p | OR (95% CI) | p | OR (95% CI) | p | |||
| PDI | ||||||||
| Quartile 1 | 1547 (42) | 28.37 | Reference | Reference | Reference | Reference | Reference | Reference |
| Quartile 2 | 1786 (48) | 28.39 | 0.91 (0.82, 1.00) | .050 | 0.90 (0.81, 1.00) | .058 | 0.90 (0.81, 1.01) | .064 |
| Quartile 3 | 1516 (52) | 28.49 | 0.64 (0.57, 0.71) | <.001 | 0.64 (0.57, 0.72) | <.001 | 0.64 (0.57, 0.72) | <.001 |
| Quartile 4 | 1287 (57) | 28.47 | 0.43 (0.38, 0.49) | <.001 | 0.45 (0.39, 0.51) | <.001 | 0.45 (0.39, 0.52) | <.001 |
| p‐value for trend | – | <.001 | – | <.001 | – | <.001 | ||
| hPDI | ||||||||
| Quartile 1 | 1536 (40) | 28.36 | Reference | Reference | Reference | Reference | Reference | Reference |
| Quartile 2 | 1603 (46) | 28.34 | 0.87 (0.79, 0.96) | .006 | 0.90 (0.81, 1.00) | .042 | 0.90 (0.81, 1.00) | .044 |
| Quartile 3 | 1745 (49) | 28.52 | 0.71 (0.64, 0.80) | <.001 | 0.76 (0.67, 0.85) | <.001 | 0.76 (0.67, 0.85) | <.001 |
| Quartile 4 | 1252 (54) | 28.51 | 0.56 (0.50, 0.63) | <.001 | 0.61 (0.54, 0.69) | <.001 | 0.61 (0.54, 0.70) | <.001 |
| p‐value for trend | – | <.001 | – | <.001 | – | <.001 | ||
| uPDI | ||||||||
| Quartile 1 | 1769 (43) | 28.73 | Reference | Reference | Reference | Reference | Reference | Reference |
| Quartile 2 | 1418 (49) | 28.46 | 1.32 (1.17, 1.49) | <.001 | 1.18 (1.04, 1.34) | .009 | 1.17 (1.03, 1.33) | .014 |
| Quartile 3 | 1723 (53) | 28.31 | 1.74 (1.56, 1.95) | <.001 | 1.48 (1.31, 1.67) | <.001 | 1.47 (1.30, 1.66) | <.001 |
| Quartile 4 | 1226 (58) | 28.15 | 2.56 (2.28, 2.88) | <.001 | 2.05 (1.81, 2.33) | <.001 | 2.03 (1.79, 2.31) | <.001 |
| p‐value for trend | – | <.001 | – | <.001 | – | <.001 | ||
Abbreviations: hPDI, healthful plant‐based diet index; PDI, overall plant‐based diet index; uPDI, unhealthful plant‐based diet index.
Because MMSE, PDI, hPDI, and uPDI were multiply measurements, descriptive statistics at baseline were reported. Model 1 was adjusted for age. Model 2 was multivariable adjusted for age (years), sex (male or female), marital status (married or unmarried), urban/rural residence, education (with or without formal education), occupation before age 60 (professional or nonprofessional work), financial status (financial independence or dependence), social and leisure activity, smoking and drinking status (never, former, or current smokers/drinkers), physical activity (yes or no), and geographic regions (Central China, Eastern China, Northeastern China, Northern China, Northwestern China, Southern China, and Southwestern China). Model 3 was additionally adjusted for BMI (<18.5, 18.5–25.0, or ≥25.0 kg/m2), vitamin A/C/E intake (almost everyday, ≥1 time/week, ≥1 time/month, occasionally, rarely, or never), and status of five cardiometabolic diseases, including hypertension, diabetes, heart disease, cerebrovascular disease, and dyslipidemia (yes, no, or unknown).