Table 2 Meta-analysis of main results of all polyphenolic compounds and subgroups

Overall (all polyphenolic compounds)

43 (14)

0.78

0.72–0.85

79.9

< 0.001

0.88

Study design

Prospective cohort

24 (6)

0.75

0.68–0.84

71.0

< 0.001

0.41

Cross-sectional

19 (8)

0.81

0.70–0.93

85.9

< 0.001

Dietary assessment

FFQ

31 (9)

0.78

0.71–0.86

82.1

< 0.001

0.87

24-hour recalls

12 (5)

0.77

0.60–0.98

74.2

< 0.001

Definition of MetS

IDF

13 (4)

0.79

0.73–0.86

32.0

0.12

0.02

The joint interim guidelines

12 (3)

0.75

0.65–0.86

0.86

< 0.001

ATP III

14 (4)

0.83

0.66–1.05

85.2

< 0.001

AHA-NHLBI

1 (1)

0.83

0.42–1.63

-

-

Korean diabetic association

1 (1)

0.11

0.02–0.61

-

-

IDF and AHA-NHLBI

2 (1)

0.99

0.85–1.17

0.0

0.57

Polyphenol subclasses

Total polyphenols

6 (5)

0.86

0.75-1.00

45.8

0.10

0.008

0.84

Total flavonoids

10 (9)

0.64

0.51-81

90.1

< 0.001

0.64

Flavan-3-ols

3 (2)

0.64

0.43–0.94

79.6

0.007

0.22

Isoflavones

4 (3)

0.84

0.75–0.93

0.0

0.47

0.08

Lignans

4 (4)

1.06

0.87–1.28

40.7

0.16

0.82

Stilbenes

4 (4)

0.86

0.76–0.97

0.0

0.88

0.08

Phenolic acids

4 (4)

0.85

0.68–1.06

37.2

0.18

0.23

Anthocyanins

2 (2)

0.91

0.81–1.01

0.0

0.86

-

Flavones

2 (2)

0.79

0.71–0.89

5.7

0.30

-

Flavonols

2 (2)

0.34

0.06–2.04

77.6

0.03

-

Quercetin

2 (2)

0.63

0.43–0.93

0.0

0.32

-