Table 1: Baseline characteristics of the 2157 subjects.

Variable	Value
Age, yr	49.2 ± 11.7
≦ 39	430 (19.9%)
40-59	1300 (60.3%)
≧ 60	427 (19.8%)
Gender, male	1037 (48.1%)
Body mass index, kg/m^2	22.5 ± 3.3
Smoking
Never	1645 (76.3%)
Current	425 (19.7%)
Previous	87 (4.0%)
Alcohol
Never	1912 (88.6%)
Current	194 (9.0%)
Previous	51 (2.4%)
H. pylori infection	828/1571 (52.7%)
Family history of GC	147 (6.8%)
Bile reflux	156 (7.2%)
Diarrhea	273 (12.7%)
Constipation	415 (19.2%)
Tea intake, ≧ 6 cups (250 ml per cup) / wk	264 (12.2%)
High salt diet, ≧ 15 g common salt / d	501 (23.2%)
Spicy food, ≧ 4 times / wk	567 (26.3%)
Vitamin C, ≧ 3 m	28 (1.3%)
The consumption of dairy products, ≧ 100 g/d	536 (24.8%)
The consumption of fruits, ≧ 300 g/d	740 (34.3%)
The consumption of vegetables, ≧ 200 g/d	1800 (83.4%)
NSAIDs use, ≧ 3 m	48 (2.2%)
Income level, ≧ 3500 RMB	911 (42.2%)
Education, above college	448 (20.8%)

Continuous variables are expressed as mean ± SD, whereas categorical data are expressed as n (%).