Introduction
Materials and methods
Study cohort
Exposure (8-item Japanese Diet Index score)
Endpoints
Ethical issues
Statistical analysis
Results
Characteristic | Groups of the JDI8 score | |||
---|---|---|---|---|
G1 (low) | G2 | G3 | G4 (high) | |
The JDI8 score | 0–2 | 3 | 4, 5 | 6–8 |
No. of participants | 16,838 | 15,461 | 36,196 | 24,474 |
Age (years), mean (SD) | 54.6 (7.9) | 56.0 (8.0) | 57.0 (7.9) | 57.4 (7.3) |
Males, n (%) | 7302 (43.4) | 6987 (45.2) | 16,476 (45.5) | 11,935 (48.8) |
Body mass index (kg/m2), n (%) | ||||
< 18.5 | 640 (3.9) | 622 (4.1) | 1345 (3.8) | 835 (3.5) |
18.5–25.0 | 10,810 (65.5) | 10,078 (66.5) | 24,170 (67.9) | 16,802 (69.3) |
25.0–30.0 | 4348 (26.3) | 3955 (26.1) | 8959 (25.2) | 5915 (24.4) |
≥ 30.0 | 706 (4.3) | 509 (3.3) | 1125 (3.1) | 680 (2.8) |
Current smoker, n (%) | 4,151 (26.2) | 3,618 (24.9) | 8,187 (24.1) | 5,698 (24.5) |
Drink alcohol every day, n (%) | 3,096 (18.8) | 2,851 (18.9) | 7,137 (20.2) | 5,446 (22.6) |
Total physical activity (MET-h/day), mean (SD) | 31.0 (6.2) | 31.3 (6.4) | 32.0 (6.5) | 32.9 (6.6) |
Medication, n (%) | ||||
Antihypertensive | 2792 (16.6) | 2935 (19.0) | 7155 (19.8) | 4743 (19.4) |
Cholesterol-lowering | 702 (4.2) | 789 (5.1) | 2123 (5.9) | 1499 (6.1) |
Hypoglycemic agents | 441 (2.6) | 489 (3.2) | 1112 (3.1) | 661 (2.7) |
Occupation, n (%) | ||||
Agriculture | 1898 (11.3) | 2578 (16.7) | 8164 (22.6) | 7466 (30.5) |
Forestry | 28 (0.2) | 70 (0.5) | 192 (0.5) | 190 (0.8) |
Fishery | 200 (1.2) | 252 (1.6) | 693 (1.9) | 337 (1.4) |
Office work | 5360 (31.8) | 4479 (29.0) | 9948 (27.5) | 6636 (27.1) |
Self-employed | 2496 (14.8) | 2144 (13.9) | 5107 (14.1) | 3507 (14.3) |
Specialty work | 1334 (7.9) | 1058 (6.8) | 2159 (6.0) | 1436 (5.9) |
Housewife | 3695 (21.9) | 3400 (22.0) | 8413 (23.2) | 5762 (23.5) |
Unemployed | 1403 (8.3) | 1523 (9.9) | 3427 (9.5) | 2107 (8.6) |
Other | 1572 (9.3) | 1286 (8.3) | 2732 (7.6) | 1658 (6.8) |
Total energy intake (kcal/day), mean (SD) | 1656 (506) | 1782 (543) | 2005 (582) | 2337 (598) |
Sodium intake (mg/day), mean (SD) | 3173 (1,348) | 3920 (7,298) | 4901 (1,971) | 6466 (2,299) |
Potassium intake (mg/day), mean (SD) | 1933 (744) | 2272 (907) | 2840 (1,061) | 3668 (1,186) |
Sodium–potassium ratio, mean (SD) | 1.7 (0.6) | 1.8 (1.7) | 1.8 (0.5) | 1.8 (0.5) |
Components of Index score + 1 point given, n (%) | ||||
Adhering components† | ||||
Rice | 4,483 (26.6) | 7,531 (48.7) | 22,499 (62.2) | 20,471 (83.6) |
Miso soup | 3,690 (21.9) | 7,176 (46.4) | 22,682 (62.7) | 20,675 (84.5) |
Seaweeds | 2,142 (12.7) | 4,702 (30.4) | 19,490 (53.9) | 20,578 (84.1) |
Pickles | 1,392 (8.3) | 3,686 (23.8) | 19,703 (54.4) | 21,704 (88.7) |
Green and yellow vegetables | 2,471 (14.7) | 4,759 (30.8) | 18,590 (51.4) | 20,665 (84.4) |
Fish | 2,183 (13.0) | 4,464 (28.9) | 19,377 (53.5) | 20,462 (83.6) |
Green tea | 3,436 (20.4) | 6,289 (40.7) | 21,698 (60.0) | 20,148 (82.3) |
Non-adhering components‡ | ||||
Beef and pork | 6,148 (36.5) | 7,776 (50.3) | 18,718 (51.7) | 13,849 (56.6) |
Groups of the JDI8 score | Each one-point increase of the JDI8 score | P trend | ||||
---|---|---|---|---|---|---|
G1 (low) | G2 | G3 | G4 (high) | |||
(n = 16,838) | (n = 15,461) | (n = 36,196) | (n = 24,474) | |||
The JDI8 score | 0–2 | 3 | 4, 5 | 6–8 | ||
Person-years | 285,843 | 267,100 | 636,870 | 445,489 | ||
All-cause mortality | ||||||
No. of death | 3159 | 3381 | 8323 | 5733 | ||
Model 1† | 1.00 (ref) | 0.93 (0.89–0.98) | 0.86 (0.82–0.89) | 0.77 (0.74–0.81) | < 0.001 | |
Model 2‡ | 1.00 (ref) | 0.94 (0.90–0.99) | 0.90 (0.86–0.94) | 0.84 (0.80–0.88) | < 0.001 | |
Model 3§ | 1.00 (ref) | 0.95 (0.90–0.99) | 0.91 (0.87–0.95) | 0.86 (0.81–0.90) | < 0.001 | |
Model 3§ | 0.97 (0.96–0.98) | < 0.001 | ||||
Cancer mortality | ||||||
No. of death | 1059 | 1129 | 2883 | 2077 | ||
Model 1† | 1.00 (ref) | 0.97 (0.89–1.06) | 0.95 (0.88–1.02) | 0.89 (0.82–0.96) | 0.003 | |
Model 2‡ | 1.00 (ref) | 0.98 (0.90–1.07) | 0.98 (0.91–1.06) | 0.94 (0.87–1.02) | 0.140 | |
Model 3§ | 1.00 (ref) | 0.99 (0.91–1.07) | 0.98 (0.91–1.06) | 0.94 (0.86–1.03) | 0.175 | |
Model 3§ | 0.99 (0.97–1.00) | 0.144 | ||||
Cardiovascular disease mortality | ||||||
No. of death | 727 | 858 | 2006 | 1399 | ||
Model 1† | 1.00 (ref) | 0.99 (0.89–1.09) | 0.85 (0.77–0.92) | 0.76 (0.69–0.84) | < 0.001 | |
Model 2‡ | 1.00 (ref) | 1.00 (0.90–1.10) | 0.90 (0.82–0.99) | 0.86 (0.78–0.95) | < 0.001 | |
Model 3§ | 1.00 (ref) | 1.01 (0.91–1.11) | 0.92 (0.84–1.01) | 0.89 (0.80–0.99) | 0.007 | |
Model 3§ | 0.97 (0.95–0.99) | 0.003 | ||||
Heart disease mortality | ||||||
No. of death | 381 | 470 | 1,051 | 698 | ||
Model 1† | 1.00 (ref) | 1.04 (0.91–1.20) | 0.87 (0.77–0.99) | 0.77 (0.67–0.88) | < 0.001 | |
Model 2‡ | 1.00 (ref) | 1.05 (0.92–1.21) | 0.93 (0.82–1.05) | 0.87 (0.75–0.99) | 0.005 | |
Model 3§ | 1.00 (ref) | 1.06 (0.93–1.22) | 0.95 (0.84–1.07) | 0.89 (0.77–1.03) | 0.037 | |
Model 3§ | 0.96 (0.94–0.99) | 0.008 | ||||
Cerebrovascular disease mortality | ||||||
No. of death | 283 | 298 | 784 | 585 | ||
Model 1† | 1.00 (ref) | 0.86 (0.73–1.01) | 0.81 (0.70–0.93) | 0.76 (0.65–0.89) | 0.001 | |
Model 2‡ | 1.00 (ref) | 0.87 (0.74–1.02) | 0.86 (0.74–0.99) | 0.85 (0.72–0.99) | 0.061 | |
Model 3§ | 1.00 (ref) | 0.88 (0.74–1.03) | 0.88 (0.76–1.02) | 0.89 (0.75–1.05) | 0.237 | |
Model 3§ | 0.98 (0.95–1.01) | 0.275 |
All-cause mortality | Cancer mortality | Cardiovascular disease mortality | Heart disease mortality | Cerebrovascular disease mortality | ||||||
---|---|---|---|---|---|---|---|---|---|---|
0 point | One point | 0 point | One point | 0 point | One point | 0 point | One point | 0 point | One point | |
Adhering components | ||||||||||
Rice† | 1.00 (ref) | 1.02 (0.99–1.06) | 1.00 (ref) | 0.98 (0.93–1.03) | 1.00 (ref) | 1.07 (1.00–1.14) | 1.00 (ref) | 1.09 (1.00–1.19) | 1.00 (ref) | 1.09 (0.99–1.21) |
Miso soup† | 1.00 (ref) | 0.98 (0.95–1.01) | 1.00 (ref) | 1.02 (0.97–1.08) | 1.00 (ref) | 0.99 (0.93–1.06) | 1.00 (ref) | 1.03 (0.94–1.12) | 1.00 (ref) | 0.97 (0.88–1.08) |
Seaweeds† | 1.00 (ref) | 0.94 (0.92–0.97) | 1.00 (ref) | 0.97 (0.93–1.02) | 1.00 (ref) | 0.93 (0.88–0.99) | 1.00 (ref) | 0.94 (0.87–1.02) | 1.00 (ref) | 0.92 (0.84–1.01) |
Pickles† | 1.00 (ref) | 0.95 (0.92–0.98) | 1.00 (ref) | 1.03 (0.97–1.08) | 1.00 (ref) | 0.96 (0.90–1.02) | 1.00 (ref) | 0.93 (0.85–1.02) | 1.00 (ref) | 0.997 (0.90–1.11) |
Green and yellow vegetables† | 1.00 (ref) | 0.94 (0.91–0.96) | 1.00 (ref) | 0.96 (0.92–1.02) | 1.00 (ref) | 0.92 (0.87–0.98) | 1.00 (ref) | 0.89 (0.82–0.97) | 1.00 (ref) | 0.97 (0.88–1.07) |
Fish† | 1.00 (ref) | 0.97 (0.94–0.997) | 1.00 (ref) | 0.98 (0.93–1.03) | 1.00 (ref) | 0.98 (0.92–1.04) | 1.00 (ref) | 1.00 (0.92–1.10) | 1.00 (ref) | 0.91 (0.82–1.01) |
Green tea† | 1.00 (ref) | 0.89 (0.86–0.91) | 1.00 (ref) | 0.96 (0.91–1.00) | 1.00 (ref) | 0.88 (0.83–0.93) | 1.00 (ref) | 0.81 (0.75–0.88) | 1.00 (ref) | 0.95 (0.86–1.04) |
Non-adhering components | ||||||||||
Beef and pork† | 1.00 (ref) | 1.02 (0.99–1.05) | 1.00 (ref) | 1.00 (0.95–1.05) | 1.00 (ref) | 1.01 (0.95–1.08) | 1.00 (ref) | 0.98 (0.90–1.07) | 1.00 (ref) | 1.03 (0.93–1.14) |