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Table 1 RCT Evidence of Omega-3 Fatty Acids to Improve Respiratory Outcomes in Asthma

From: Treating asthma with omega-3 fatty acids: where is the evidence? A systematic review

 

Study groups1

  

Author, Year, Location: Length & Design

Group 1 (n)/Group 4 (n)

Group 2 (n)/Group 3 (n)

Jadad Total Quality/Allocation Concealment (Internal Validity)

Applicability

ADULTS

Arm, 1988[18] England: 10-wk parallel RCT

3.2 g/d EPA + 2.2 g/d DHA (n = NR)

Olive oil placebo (dose: NR) (n = NR)

4/Unclear

III

Emelyanov, 2002[23] Russia: 8-wk parallel RCT

200 mg/d EPA/DHA + 400 mg/d olive oil (n = 23)

600 mg/d olive oil placebo (n = 23)

5/Unclear

III

Kirsch, 1988[22] USA: 8-wk parallel RCT

4.0 g/d EPA ethyl ester (+ trace DHA) (n = 6)

0.1 g/d EPA ethyl ester (+ trace DHA) (n = 6)

3/Unclear

I

McDonald, 1991[15] Australia: 10-wk crossover RCT

2.7 g/d EPA + 1.8 g/d DHA (n = 15)

15 g/d olive oil placebo (n = 15)

3/Unclear

III

Okamoto, 2000[19] Japan: 4-wk RCT

10–20 g/d perilla seed oil (ALA: NR) (n = 7)

10–20 g/d corn oil (n = 7)

2/Unclear

III

Stenius-Aarniala, 1989[21] Finland: 10-wk crossover RCT

20 mL/d fish oil (EPA+DHA: NR) (n = 36)

20 mL/d olive oil (n = 36)/20 mL/d evening primrose oil (n-6) (n = 36)

2/Unclear

III

Thien, 1993[20] England: 26-wk parallel RCT

3.2 g/d EPA + 2.2 g/d DHA (n = NR)

Olive oil placebo (dose: NR) (n = NR)

4/Unclear

III

CHILDREN

Hodge, 1998[17] Australia: 26-wk parallel RCT

0.72 g/d EPA 0.48 g/d DHA + ALA (dose: NR) via canola diet (n = NR)

n-6: 1.8 g/d safflower oil + 1.8 g/d palm oil + 0.4 g/d olive oil + sunflower diet (dose: NR) (n = NR)

3/Unclear

III

Nagakura, 2000[16] Japan: 10-mo parallel RCT

17.0–26.8 mg/kg/d EPA; 7.3–11.5 mg/kg/d DHA (300 mg/d fish oil) (n = 15)

300 mg/d olive oil placebo (n = 15)

4/Unclear

III

AGE NOT REPORTED

Dry, 1991[24] France: 9-mo parallel RCT

1.0 g/d EPA+DHA (n = NR)

"Placebo" (type & dose: NR) (n = NR)

2/Unclear

X

  1. 1Proceeding from highest omega-3, or lowest omega-6/omega-3, fatty acid content of intervention; n-6 = omega-6 FAs; ALA = alpha linolenic acid; DHA = docosahexaenoic acid; EPA = eicosapentaenoic acid; Length = intervention length; Design = research design; n = sample size; pts = study participants; NR = not reported; wk = week(s); mo = month; RCT = randomized controlled trial; Jadad total quality score = /5; Applicability I = greatest applicability to North American population of asthma patients; Applicability II = somewhat narrow applicability; Applicability III = very narrow applicability; Applicability X = insufficient data to determine applicability