Table 1.

Study characteristics.

Cluster	First Author (Year)	Study Design	Population	Asthma Diagnosis	Intervention and Dose ##	Study Duration	n	Age (Years)	Male (%)
Herbs, herbal mixtures and extracts	Barlianto (2017) * Barlianto (2018) * [34,35]	Parallel	Children with asthma	GINA guidelines	Nigella sativa oil 15–30 mg/kg/day	8 weeks	28	9 #	39 #
	Hosseini (2018) ** Zilaee (2019) ** [36,37]	Parallel	Adults with mild-to-moderate asthma	GINA guidelines	Saffron 100 mg/day	8 weeks	76	41 #	63 #
	Khayyal (2003) [38]	Parallel	Adults with mild-to-moderate asthma	National Institutes of Health and GINA guidelines	Aqueous extract of propolis 13% solution, equivalent to active constituents in 2 mL of aqueous extract of propolis per day	2 months	46	Range: 19–52	78 #
	Koshak (2017) [39]	Parallel	Adults with asthma	GINA guidelines and ACT score	Nigella sativa oil 1 g/day	4 weeks	80	41 #	41 #
	Salem (2017) [40]	Parallel, 3 arms	Adults with asthma	Previous physician’s diagnosis and National Institutes of Health criteria	Nigella sativa (low dose) 1 g/day	12 weeks	76	38 #	34 #
					Nigella sativa (high dose) 2 g/day
	Yugandhar (2017) [41]	Parallel	Adults with bronchial asthma	Previous physician’s diagnosis	Extract of B. serrata gum resin and A. marmelos fruit 200 mg/day	56 days	29	39 #	41 #
Supplements	Ghaffari (2014) [42]	Parallel	Children with moderate asthma	Previous physician’s diagnosis	Vitamin E 50 mg/day	8 weeks	240	9 #	54 #
	Pearson (2004) [43]	Parallel	Adults with asthma	Previous physician’s diagnosis and medication use	Vitamin E 500 mg/day	6 weeks	72	48	46
	Smith (2015) [44]	Parallel	Children and adults with asthma	Previous physician’s diagnosis, symptoms and medication use	Soy isoflavone 100 mg/day	6 months	386	36	34
	Wood (2008) [45]	Crossover, 3 arms	Adults with stable asthma	Previous physician’s diagnosis, symptoms and airway hyper-responsiveness	Tomato extract 45 mg lycopene/day	7 days	22	52	36
					Tomato juice 45 mg lycopene/day
Weight loss	Dias-Junior (2014) [46]	Parallel	Obese adults with severe asthma	Previous physician’s diagnosis and treatment according to GINA guidelines	Low-calorie intake, use of sibutramine (10 mg/day) and use of orlistat (max. 120 mg/day)	6 months	33	43 #	6 #
	Jensen (2013) [47]	Parallel	Obese children with asthma	Previous physician’s diagnosis	Energy reduction (−500 kcal/day) and counseling sessions	10 weeks	28	12 #	61 #
	Toennesen (2018) 1 [48]	Parallel, 4 arms	Adults with asthma	ACQ score and positive diagnostic test	High protein and low glycemic index diet	8 weeks	125	40 #	31 #
					Combination of diet and exercise
Vitamin D3	Bar Yoseph (2015) [49]	Parallel	Children with mild asthma	Previous physician’s diagnosis, positive methacholine challenge test	Vitamin D3 14.000 IU/week	6 weeks	39	13 #	64 #
	Castro (2014) [50]	Parallel	Adults with symptomatic asthma	Previous physician’s diagnosis, evidence of bronchodilator reversibility or airway hyper-responsiveness	Vitamin D3 100.000 IU once, followed by 4000 IU/day	28 weeks	408	40 #	32 #
	de Groot (2015) [51]	Parallel	Adults with nonatopic asthma	Evidence of bronchodilator reversibility or airway hyper-responsiveness	Vitamin D3 (cholecalciferol) 400.000 IU single dose	9 weeks	44	56 #	59 #
	Kerley (2016) [52]	Parallel	Children with uncontrolled asthma	Previous physician’s diagnosis and medication use according to GINA guidelines	Vitamin D3 2000 IU/day	15 weeks	39	8 #	62 #
	Martineau (2015) [53]	Parallel	Adults with asthma	Previous physician’s diagnosis, evidence of bronchodilator reversibility	Vitamin D3 (Vigantol oil) 120.000 IU/2 months	1 year	250	48 #	44 #
Omega-3 LCPUFA	Emelyanov (2002) [54]	Parallel	Adults with mild-to-moderate atopic asthma	American Thoracic Society asthma definition	Lipid extract of the New Zealand green-lipped mussel 200 mg/day EPA + DHA	8 weeks	46	39 #	26 #
	Hodge (1998) [55]	Parallel	Children with asthma and a history of episodic wheeze in the last 12 months and airway hyperresponsiveness to histamine	Symptoms and airway hyper-responsiveness	Omega-3 fatty acid-rich diet and omega-3 fatty acid supplementation 1200 mg/day EPA + DHA	6 months	39	10 #	41 #
	Mickleborough (2013) [56]	Crossover	Adults with mild-to-moderate persistent asthma	Previous physician’s diagnosis	Marine lipid fraction PCSO-524™ 400 mg/day omega-3 LCPUFA, of which 120 mg/day EPA + DHA	3 weeks	20	23	60
	Moreira (2007) [57]	Parallel	Adults with stable, persistent asthma	Previous physician’s diagnosis and use of inhaled corticosteroids	N-3 PUFA 780 mg/day EPA+DHA 10 mg/day vitamin E	2 weeks	20	38 #	0
	Schubert (2009) 2 [58]	Parallel	Adults with asthma and house dust mite allergy	Unknown	N-3 PUFA-enriched fat blend 750 mg/day (of which 630 mg/day EPA + DHA)	3 weeks	23	24 #	43 #
Whole food approaches	Bseikri (2018) [59]	Parallel	Obese adolescents with asthma	Previous physician’s diagnosis and ACQ score	Nutrient-dense bar (CHORI-bar) 2 bars/day	2 months	56	15 #	55 #
	Papamichael (2019) [60]	Parallel	Children with mild asthma	Previous physician’s diagnosis and GINA guidelines	Two meals with fatty fish per week as part of the Greek Mediterranean diet	6 months	64	8 #	52 #
	Sexton (2013) [61]	Parallel, 3 arms	Adults with symptomatic asthma	Previous physician’s diagnosis, bronchodilator reversibility or PEFR variability during run-in	High-intervention: encouraged to adopt a Mediterranean diet and received intensive initial advice and 41 h of consultation sessions with a dietitian	12 weeks	35	38 #	29 #
					Low intervention: received less intensive advice and spent 2 h with a dietitian
	Sudini (2016) [62]	Parallel	Adults with asthma and a positive skin test to an indoor allergen	Previous physician’s diagnosis	Broccoli sprouts 100 g/day	3 days	40	34 #	40 #
	Wood (2012) 2 [63]	Parallel	Adults with stable asthma	Previous physician’s diagnosis, symptoms and airway hyper-responsiveness	High antioxidant diet	14 days	137	57 #	42 #

Abbreviations: ACT = asthma control test; ACQ = asthma control questionnaire; DHA = docosahexaenoic acid; EPA = eicosapentaenoic acid; GINA = Global Initiative for Asthma; IU = international unit; (LC)PUFA = long-chain polyunsaturated fatty acid; PEFR = peak expiratory flow rate; ¹ = exercise arm not included in this review; ² = not all data of this article could be extracted; */** = articles were based on the same study; ^# = calculated; ^## = habitual intake and reference data for nutritional interventions is presented in Supplemental Table S2.