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Table 2 Hazard ratio and 95% confidence interval of breast cancer 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 intake assessed by baseline questionnaire

    
 

Less than one cup per week

One to two cups per week

Three to four cups per week

One to two cup per day

Three to four cups per day

Five or more cups per day

 

P for trend

No. of cases

68

50

36

117

160

150

  

Person-years

87,841

56,200

40,912

152,896

201,005

194,813

  

Age- and area-adjusted HR (95% CI)

1.00

1.18

(0.82 to

1.71)

1.17

(0.78 to

1.75)

1.11

(0.82 to

1.50)

1.18

(0.88 to

1.59)

1.12

(0.83 to

1.51)

   

0.58

Multivariate HR (95% CI)*

1.00

1.19

(0.80 to

1.76)

1.13

(0.72 to

1.75)

1.13

(0.81 to

1.58)

1.17

(0.85 to

1.62)

1.12

(0.81 to

1.56)

   

0.60

 

Green tea intake assessed by five-year follow-up questionnaire

 
 

Less than one cup per week

One 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

Ten or more cups per day

P for trend

Sencha

                    

No. of cases

82

56

35

63

78

18

18

 

Person-years

91,228

75,237

38,328

85,491

73,160

27,641

21,715

 

Age- and area-adjusted HR (95% CI)

1.00

0.79

(0.56 to

1.12)

1.02

(0.68 to

1.52)

0.83

(0.59 to

1.16)

1.22

(0.88 to

1.69)

0.74

(0.44 to

1.26)

0.92

(0.55 to

1.55)

0.77

Multivariate HR (95% CI)†

1.00

0.71

(0.46 to

1.08)

0.97

(0.59 to

1.58)

0.85

(0.57 to

1.27)

1.25

(0.84 to

1.86)

0.68

(0.36 to

1.31)

1.02

(0.55 to

1.89)

0.48

Bancha/Genmaicha

                    

No. of cases

107

90

38

69

30

7

9

 

Person-years

123,189

99,201

42,254

76,532

46,563

14,733

10,329

 

Age- and area-adjusted HR (95% CI)

1.00

1.02

(0.77 to

1.36)

1.05

(0.72 to

1.53)

1.09

(0.80 to

1.49)

0.80

(0.53 to

1.21)

0.58

(0.27 to

1.26)

1.02

(0.52 to

2.02)

0.41

Multivariate HR (95% CI)†

1.00

1.12

(0.80 to

1.58)

1.23

(0.79 to

1.92)

1.23

(0.85 to

1.78)

0.83

(0.51 to

1.35)

0.70

(0.28 to

1.76)

0.86

(0.34 to

2.17)

0.66

 

Total green tea intake assessed by five-year follow-up questionnaire‡

 
 

0

1 to 119 ml per day

120 to 299 ml per day

300 to 599 ml per day

600 to 959 ml per day

960 to 1319 ml per day

1320 ml + per day

P for trend

No. of cases

13

44

48

85

105

28

27

 

Person-years

18,312

50,715

58,499

91,109

114,255

44,745

35,166

 

Age- and area-adjusted HR (95% CI)

1.00

1.25

(0.67 to

2.32)

1.25

(0.67 to

2.32)

1.47

(0.81 to

2.67)

1.48

(0.82 to

2.67)

1.02

(0.52 to

2.00)

1.20

(0.61 to

2.36)

0.88

Multivariate HR (95% CI)§

1.00

1.08

(0.52 to

2.23)

1.26

(0.62 to

2.56)

1.59

(0.81 to

3.14)

1.43

(0.73 to

2.83)

0.89

(0.40 to

1.97)

1.29

(0.60 to

2.79)

0.70

  1. *,†,§ Adjusted for age (continuous), area (10 public health centers), age at menarche (continuous), menopausal status at baseline (premenopausal women, age at menopause for postmenopausal women (* - 47, 48 to 50, 51 to 53, 54+; †,§ - 44, 45 to 49, 50 to 54, 55+)), number of births (0, 1, 2, 3, 4, 5+), age at first birth (-21, 22 to 25, 26 to 29, 30+, nulliparous), height (continuous), BMI (continuous), alcohol intake (non-drinkers, occasional drinkers, -150 (g per week) and 150+ (g per week) among regular drinkers (ethanol)), smoking status (never, past, current), *leisure time physical activity (no, one to three days per month, more than one day per week), †,§ daily physical activity (metabolic equivalent-hours per day) (continuous), exogenous hormone use (never, past, current), family history of breast cancer (yes, no), oolong tea intake (*less than one cup per week, one to four cups per week, one or more cups per day; †,§ less than 1 cup per week, one to six cups per week, one or more cups per day), black tea intake (*less than one cup per week, one to four cups per week, one or more cups per day; †,§ less than one cup per week, one to six cups per week, one or more cups per day), coffee intake (*less than one cup per week, one to four cups per week, one to two cups per day, three or more cups per day; †,§ less than one cup per week, one to six cups per week, one or more cups per day), †,§ canned coffee intake (less than one cup per week, one to six cups per week, one or more cups per day), and †Sencha and Bancha/Genmaicha intake.
  2. Models for Sencha or Bancha/Genmaicha intake did not include these variables, respectively.
  3. ‡ Total green tea intake was defined as the sum of Sencha and Bancha/Genmaicha intake (ml per day).
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Breast Cancer Research

ISSN: 1465-542X

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