Table 1 Characteristics of included studies

Ahnfeldt-Mollerup et al. 2015 [32]

Denmark

EG: 28

CG: 25

23/30

EG: 67

CG: 70

/

/

I-IV

EG: complex (134.8 kcal, 9.3 g protein, 14.6 g CHO, 4.2 g fat) + exercise

CG: placebo + exercise

9 weeks

SGRQ

Aldhahir et al. 2021 [33]

UK

EG: 22

CG: 22

28/16

EG: 75

CG: 70

EG: 59

CG: 52

EG: 53

CG: 54

/

EG: complex (300 kcal, 24% protein, 41% CHO, 35% fat) + exercise

CG: placebo + exercise

6 weeks

CAT

Khan et al. 2016 [34]

India

EG: 30

CG: 30

54/6

EG: 55.03

CG: 53.33

EG: 52.87

CG: 53.31

EG: 69.44

CG: 67.62

I-IV

EG: complex (90 kcal, 45% protein, 55%CHO)

CG: placebo

12 weeks

6MWD、FEV1/FVC

FEV1 (% of predicted)

Zong et al. 2023 [35]

China

EG: 27

CG: 29

28/28

EG: 80.5

CG: 81.1

EG: 71.7

CG: 67.2

EG: 63.3

CG: 61.8

II-III

EG: whey proteins (10 g/day)

CG: placebo

12 weeks

mMRC、CAT、6MWD、FEV1 (% of predicted)

Gurgun et al. 2013 [36]

Turkey

EG: 15

CG: 16

31/0

EG: 66.8

CG: 67.8

EG: 41.9

CG: 41.9

EG: 53.4

CG: 43.9

III-IV

EG: complex (16.7% protein, 53.3% CHO, 30% fat) + exercise

CG: placebo + exercise

8 weeks

mMRC、6MWD、SGRQ

Zarei et al. 2024 [37]

Iran

EG: 30

CG: 30

29/31

EG: 60.83

CG: 59.97

EG: 36.77

CG: 44.87

EG: 60.1

CG: 64.52

III-IV

EG: Nanocurcumin (80 mg/day)

CG: placebo

3 months

FEV1/FVC、

FEV1 (% of predicted)

Cerda et al. 2006 [38]

Spain

EG: 15

CG: 15

30/0

EG: 60

CG: 63.4

EG:46

CG: 35.1

EG: 46.59

CG: 43.24

II-IV

EG: pomegranate juice (400 ml/day)

CG: placebo

5 weeks

FEV1/FVC

Gouzi et al. 2019 [39]

France

EG:31

CG:26

28/29

EG: 62.4

CG: 61.1

EG: 57

CG: 62

EG: 41

CG: 43

/

EG: VE + VC (VE 30 mg/day, VC 180 mg/day) + exercise

CG: placebo + exercise

28 days

6MWD

Alasmari et al. 2024 [19]

UK

EG: 36

CG: 34

48/22

EG: 62.5

CG: 64.5

EG: 45.2

CG: 39.6

/

/

EG: nitrate (400 mg/day)

CG: placebo

3 months

CAT、6MWD

Beers et al. 2020 [40]

Netherland

EG: 42

CG: 39

41/40

EG: 62.8

CG: 62.2

EG: 57

CG: 53

EG: 44.4

CG: 41.6

/

EG: complex (protein, carbohydrates, fat and micronutrients, and was enriched with leucine, omega-3, and vitamin D )

CG: placebo

4 months

SGRQ

Benedetto et al. 2018 [23]

Italy

EG: 45

CG: 45

68/22

EG: 73

CG: 73

EG: 52

CG: 57

/

/

EG: 160 mg Coenzyme Q10+ 170 mg creatine

CG: placebo

2 months

6MWD、mMRC、FEV1 (% of predicted)

Behnia et al. 2018 [41]

USA

EG:12

CG:13

13/12

EG: 67

CG: 68

/

EG: 57

CG: 61

I-IV

EG: nitrate (70 ml of beetroot juice plus 180 ml of black currant juice)

CG: placebo (70 ml of water and 180 ml of black currant juice)

8 weeks

SGRQ、FEV1/FVC

Bool et al. 2017 [42]

Netherland

EG: 42

CG: 39

41/40

EG: 62.8

CG: 62.2

EG: 57

CG:53

EG: 44.4

CG: 41.6

/

EG: complex (187.5 kcal, 20% protein, 60% CHO, 20% fat and was enriched with leucine, Omega-3, and vitamin D)

CG: placebo

4 months

6MWD

Brandt et al. 2022 [43]

Belgium

EG: 21

CG: 19

30/10

EG: 66

CG: 65

EG: 55.2

CG: 55.6

EG: 46.1

CG: 50.4

I-IV

EG: beta alanine (3.2 g/day )

CG: placebo

12 weeks

6MWD

Brockwell et al. 2014 [44]

UK

EG: 20

CG: 13

25/8

EG: 66.9

CG: 67.3

EG: 57.9

CG: 57.3

/

/

EG: AKL1 (comprising standardized extracts of Picrorhiza kurroa, Ginkgo biloba, and Zingiber officinale)

CG: placebo

10 weeks

SGRQ、6MWD、mMRC、

FEV1 (% of predicted)

Faager et al. 2006 [45]

Solna

EG: 10

CG: 13

10/13

EG: 66

CG: 66

EG: 44

CG: 41.9

/

/

EG: creatine (0.3 g/kg / body weight/day for one week,

0.07 g/kg / body weight/dayfor 7 weeks) + exercise

CG: placebo + exercise

8 weeks

SGRQ、

FEV1 (% of predicted)

Foumani et al. 2019 [21]

Iran

EG: 32

CG: 31

60/3

EG: 67.9

CG: 68.4

EG: 58.93

CG: 58.18

EG: 57.74

CG: 58.9

I-IV

EG: VD (50,000 IU )

CG: placebo (gelatin)

4 months

CAT、FEV/FVC、FEV1 (% of predicted)

Fuld et al. 2005 [46]

UK

EG: 18

CG: 20

23/15

EG: 61.7

CG: 63.7

EG: 45.4

CG:45.4

EG: 35.9

CG:40.9

/

EG: creatine (5.7 g, three times daily ) + exercise

CG: placebo + exercise

2 weeks

SGRQ

Fulton et al. 2017 [47]

Australia

EG: 6

CG: 6

7/5

EG: 68.5

CG: 70.5

EG: 72

CG: 50

EG: 59

CG: 46

/

EG: fish oil (300 mg EPA + 200 mg DHA /day)

CG: placebo (corn oil)

16 weeks

FEV1/FVC、6MWD、FEV1 (% of predicted)

Ingadottir et al. 2019 [48]

Iceland

EG: 19

CG: 15

10/24

EG: 72

CG: 73

EG: 37.2

CG: 37.3

/

/

EG: complex (300 kcal, 12 g Protein)

CG: placebo (snacks )

12 months

SGRQ

Karim et al. 2022 [20]

United Arab Emirates

EG: 51

CG: 53

/

EG: 66.9

CG: 68.3

EG: 59.88

CG: 63.76

/

/

EG: probiotic (one capsule a day, Each capsule contains 112 billion live bacteria)

CG: placebo

16 weeks

FEV1 (% of predicted)

Kim et al. 2021 [22]

USA

EG: 20

CG: 20

22/18

EG: 67.5

CG: 62.2

EG: 45.2

CG: 42.6

EG: 44

CG: 40

II-IV

EG: fish oil (650 mg EPA + 182 mg DHA /day)

CG: placebo (corn oil)

6 months

SGRQ、FEV1/FVC、6MWD、

FEV1 (% of predicted)

Lu et al. 2018 [49]

Taiwan

EG: 13

CG: 14

/

EG: 71

CG: 72

EG: 65.92

CG: 67.50

EG: 52.85

CG: 51.50

/

EG: OPC (50 mg/day)

CG: placebo

3 weeks

FEV1/FVC、

FEV1 (% of predicted)

Martínez et al. 2017 [50]

Peru

EG: 38

CG: 49

62/25

EG: 52.18

CG: 35

EG: 68.2

CG: 76.1

/

I-III

EG: complex (258 kcal, 9.4 g protein, 4.2 g

DHA, 3 g Prebiotics, 25–30% vitaminas and minerales)

CG: placebo

3 months

6MWD、SGRQ

Marinari et al. 2013 [51]

Italy

EG: 30

CG: 25

/

EG: 73.2

CG: 73.9

/

/

/

EG: 320 mg Coenzyme Q10 + Creatine 340 mg

CG: placebo

2 months

6MWD、mMRC

Negro et al. 2010 [52]

Italy

EG: 16

CG: 16

25/7

EG: 75

CG: 75

/

EG: 39

CG: 38

/

EG: EAA (4 g/day)

CG: placebo

3 months

SGRQ

Negro et al. 2012 [53]

Italy

EG: 44

CG: 44

61/27

EG: 75

CG: 73

/

EG: 39.49

CG: 37.7

/

EG: EAA (4 g/day)

CG: placebo

3 months

FEV1/FVC、SGRQ

Ogasawara et al. 2018 [54]

Japan

EG: 24

CG: 21

9/36

EG: 77.4

CG: 79.1

EG: 64.2

CG: 68.2

/

I-IV

EG: EPA (300 mg/day)

CG: placebo

12 weeks

mMRC、CAT

Pavitt et al. 2020 [55]

UK

EG: 57

CG: 65

53/69

EG: 70

CG: 68

EG: 53

CG: 48

/

II-III

EG: nitrate (0.8 g /day)

CG: placebo

8 weeks

CAT、mMRC

Qaisar et al. 2024 [56]

United Arab Emirates

EG: 52

CG: 59

/

EG: 67.1

CG: 65.5

EG:60.1

CG:61.9

/

I-IV

EG: butyrate (300 mg, capsules, take one capsule a day)

CG: placebo

12 weeks

FEV1 (% of predicted)

Rafiq et al. 2017 [57]

Netherland

EG: 24

CG: 26

26/24

EG: 64

CG: 61

EG: 58.46

CG: 58.95

EG: 48.76

CG: 48.46

I-IV

EG: VD (1,200 IU colecalciferol )

CG: placebo

6 months

FEV1/FVC、6MWD、FEV1 (% of predicted)

Sugawara et al. 2010 [58]

Japan

EG: 17

CG: 15

/

EG: 77.3

CG: 78.2

EG: 53.3

CG: 58.1

EG: 42.8

CG: 45.0

/

EG: complex (400Kcal, 60% CHO, 25% fat, 15%

protein)

CG: placebo

12 weeks

6MWD

Sugawara et al. 2012 [59]

Japan

EG: 17

CG: 14

29/2

EG: 77.4

CG: 77.1

EG: 43.4

CG: 48.6

EG: 39.8

CG: 39

/

EG: whey proteins + exercise

CG: placebo + exercise

12 weeks

6MWD、mMRC

Viana et al. 2023 [60]

Brazil

EG: 18

CG: 21

24/15

EG:67

CG:66.2

EG: 41.3

CG: 43.9

NR

/

EG: MLT (3 mg /day) + exercise

CG: placebo + exercise

12 weeks

6MWD、mMRC、CAT

Vermeeren et al. 2004 [61]

Netherland

EG: 23

CG: 24

32/15

EG:66

CG: 65

EG: 32

CG: 34

EG: 48

CG: 47

I-IV

EG: complex (1046 kJ, 20%protein, 60%CHO, 20% fat )

CG: placebo

6 days

FEV1(% of predicted)

Wu et al. 2007 [62]

Taiwan

EG1: 9

EG1: 9

EG1: 9

CG: 8

27/8

EG1: 71

EG2: 72

EG3: 68

CG: 65.1

EG1: 54

EG2: 51

EG3: 51

CG: 51

EG1: 59

EG2: 52

EG3: 50

CG: 52

/

EG1: VE400 (vitamin E 400 mg/day)

EG2: VE200 (vitamin E 200 mg/day)

EG3: VC250 (vitamin C 250 mg/day)

CG: placebo

12 weeks

FEV1 (% of predicted)

、FEV1/FVC

Zhao et al. 2012 [63]

China

EG: 26

CG: 23

46/3

EG: 80.1

CG: 80.8

EG: 39.7

CG: 38.2

/

/

EG: Yam-Epimedium (30 g Rhizoma Dioscoreae and 12 g Herba Epimedii)

CG: placebo

3 months

FEV1 (% of predicted)

、6MWD、mMRC、SGRQ