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Table 1 Baseline characteristics according to green tea intake*

From: Green tea drinking and subsequent risk of breast cancer in a population to based cohort of Japanese women

 

Green tea assessed by baseline questionnaire

Green tea assessed by five-year follow-up questionnaire, Sencha

Green tea assessed by five-year follow-up questionnaire, Bancha/Genmaicha

 

Less than one cup per week

One to two cups per day

Five or more cups per day

Less than one cup per week

Two to three cups per day

Ten or more cups per day

Less than one cup per week

Two to three cups per day

Ten or more cups per day

No. of subjects

6,202

11,322

14,308

9,638

9,052

2,281

13,053

8,148

1,099

Age (year), mean

50.4

50.8

53.9

58.2

57.0

58.9

57.5

57.8

59.7

Residential area (town or village), %

40.9

57.3

68.5

58.7

66.4

73.2

66.9

64.0

60.2

Family history of breast cancer, %

0.7

1.2

1.1

0.9

1.5

0.8

1.3

1.1

0.9

Premenopausal women, %

46

47

31

21

24

15

23

22

14

Age at menopause (year), mean†

49.2

49.3

49.4

-

-

-

-

-

-

Age at menopause (50 to 54 years old), %

-

-

-

46

50

47

47

49

46

Age at menarche (year), mean†

15.0

14.6

14.7

15.0

14.6

14.7

14.7

14.7

14.9

Number of births, mean†

2.9

2.7

2.7

3.0

2.6

2.7

2.7

2.7

2.9

Age at first birth (year), mean†

24.8

25.0

24.9

24.6

25.0

25.0

25.0

24.8

24.6

Use of exogenous female hormones (current use), %

1.4

1.0

1.0

2.9

2.4

2.1

2.4

2.3

2.3

Height (cm), mean†

150.9

152.0

152.2

151.1

152.0

152.3

151.8

151.7

151.9

Body mass index (kg/m2), mean†

23.6

23.3

23.4

23.7

23.3

23.4

23.4

23.4

23.6

Smoking (current smoker), %

7.9

6.5

7.0

5.6

4.4

8.0

6.1

4.1

8.4

Alcohol drinking (regular drinker), %

11

14

11

9.7

13

13

13

11

12

Leisure-time physical activity (≥ once per week), %

15

18

18

-

-

-

-

-

-

Physical activity (metabolic equivalent to hours per day), mean†

-

-

-

32.0

31.9

32.2

31.8

32.1

32.4

Vitamin supplement user, %

20

19

20

12

16

15

15

15

13

Bancha/Genmaicha intake (≥ four cups per day), %

-

-

-

30

6.2

25

-

-

-

Sencha intake (≥ four cups per day), %

-

-

-

-

-

-

43

14

44

Oolong tea intake (≥ one cup per day), %

20

17

10

11

12

8.8

11

13

11

Black tea intake (≥ one cup per day), %

2.8

5.0

3.2

2.6

5.2

3.8

3.3

5.0

4.4

Coffee intake (≥ one cup per day), %

41

49

28

36

40

22

34

40

27

Canned coffee intake (≥ one cup per day), %

-

-

-

4.3

2.7

2.2

2.8

3.2

2.8

Total energy intake (kcal/day), mean†‡

1,770.0

1,764.0

1,805.2

1,770.1

1,923.5

2,194.0

1,833.9

1,934.6

2,185.8

Fish and shellfish intake (g/day), mean†‡

105.5

102.8

105.4

79.6

97.5

114.3

88.2

97.0

105.3

Meats intake (g/day), mean†‡

67.2

65.2

66.1

59.7

60.4

67.7

56.6

61.6

71.6

Vegetable intake (g/day), mean†‡

293.8

293.7

295.7

217.0

247.7

319.9

234.9

245.8

327.0

Fruit intake (g/day), mean†‡

175.9

177.3

180.8

208.5

269.9

359.3

243.1

270.1

323.7

Isoflavone intake (mg/day), mean†‡

31.6

32.2

33.5

37.5

43.3

54.7

41.5

42.0

54.8

  1. * Three categories were chosen from six or nine precoded categories, respectively: less than one cup per week, one to two cups per week, three to four cups per week, one to two cups per day, three to four cups per day, and five or more cups per day for baseline questionnaire, and less than one cup per week, one to two cups per week, three to four cups per week, five to six cups per week, one cup per day, two to three cups per day, four to six cups per day, seven to nine cups per day, and ten or more cups per day for five to year follow-up questionnaire.
  2. †Adjusted for age.
  3. ‡ Intake for each subject was estimated from the food frequency questionnaires based on a regression function derived from the validation study data (baseline questionnaire only).
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Breast Cancer Research

ISSN: 1465-542X

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