Asthma Management Handbook

Healthy eating for asthma

Recommendations

Encourage healthy eating for all patients with asthma. Explain that there is emerging evidence that some healthy eating habits may also help with lung health:

  • eating plenty of fruit and vegetables every day
  • minimising intake of processed and take-away foods that are high in saturated fats.
How this recommendation was developed

Consensus

Based on clinical experience and expert opinion (informed by evidence, where available), with particular reference to the following source(s):

  • Wood et al. 20111
  • Wood et al. 20122

Do not routinely recommend dietary restrictions such as low-salt diets, or avoiding dairy foods or food additives, as strategies for managing asthma.

How this recommendation was developed

Consensus

Based on clinical experience and expert opinion (informed by evidence, where available), with particular reference to the following source(s):

  • Ardern and Ram, 20013
  • National Asthma Council Australia, 20124
  • Pogson et al. 20085
  • Zhou et al. 20126

If patients are interested in trying food supplements to help manage their asthma, provide up-to-date information about evidence and explain that no dietary supplements have been shown to improve asthma.

Table. Effects of dietary strategies in asthma management Opens in a new window Please view and print this figure separately: http://www.asthmahandbook.org.au/table/show/56

How this recommendation was developed

Consensus

Based on clinical experience and expert opinion (informed by evidence, where available), with particular reference to the following source(s):

  • Hasselmark et al. 19937
  • Paul et al. 20128
  • Pogson et al. 20085
  • Rowe and Camargo, 20089
  • Shaheen et al. 200710
  • Sur et al. 199311
  • Thien et al. 200212
  • Wood et al. 20122
  • Welsh et al. 201013

More information

Antioxidants and fats

For people with asthma, a diet high in antioxidant-rich foods (5 servings of vegetables and 2 servings of fruit every day) may help reduce the risk of asthma flare-ups and improve lung function, compared with a low-antioxidant diet (2 or fewer servings of vegetables and 1 serving of fruit per day).2

Fish oil supplementation does not appear to improve asthma control,12 but there is limited evidence from very small studies that fish oil may help control exercise-induced bronchoconstriction.14,  15

A high-fat diet may increase risk for poor asthma control by promoting inflammation, based on evidence from studies measuring inflammatory markers immediately after dietary challenge in adults with asthma:

  • A meal high in saturated fats led to increased concentrations of sputum inflammatory markers and reduced efficacy of bronchodilator (salbutamol) 4 hours later, compared with a low-fat meal.1
  • A meal high in trans fats led to higher concentrations of sputum inflammatory markers than a meal with no trans fats.1

Table. Effects of dietary strategies in asthma management Opens in a new window Please view and print this figure separately: http://www.asthmahandbook.org.au/table/show/56

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Efficacy of dietary restrictions

A low-sodium diet does not appear to improve asthma control.16 Some small clinical trials have suggested that, in people with exercise-induced bronchoconstriction, a low-sodium diet might improve lung function after exercise, but the clinical importance of this is unknown.16

Overall, evidence from studies assessing links between the common food additive tartrazine (FSANZ number 102) does not show that tartrazine worsens asthma, or that avoiding tartrazine improves asthma for people without known sensitivity to tartrazine.3

There is not enough evidence to determine whether or not avoidance of monosodium glutamate (FSANZ number 621) affects asthma control.6

Eliminating dairy foods is not an effective strategy for improving asthma control in people without proven allergies to dairy foods, and could impair nutrition, growth or bone density.4 Food allergies rarely trigger asthma.17

Table. Effects of dietary strategies in asthma management Opens in a new window Please view and print this figure separately: http://www.asthmahandbook.org.au/table/show/56

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Magnesium supplements (oral)

Overall, evidence from randomised controlled clinical trials does not support routine use of long-term oral magnesium supplementation in the treatment of asthma.9

  • A placebo-controlled clinical trial reported improvements in lung function and quality of life, compared with baseline, in adults with asthma who took oral magnesium supplements for 6.5 months. The intervention group showed improvement in quality of life and asthma control compared with baseline, but the study did not report comparisons with placebo.18
  • Another small clinical trial in adults reported that magnesium supplementation was associated with improvement in symptom scores, compared with placebo.19
  • Another clinical trial in adults with asthma reported no benefit from 16 weeks’ oral magnesium supplementation, compared with placebo.20
  • A small clinical trial in children reported that 2 months’ treatment with oral magnesium was associated with reduced flare-ups compared with placebo, but did not affect lung function.21
  • Another small clinical trial in children reported that 12 weeks’ treatment with oral magnesium reduced reliever use, compared with placebo.22

Note: IV and nebulised magnesium sulfate may be used in the management of acute asthma.

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Caffeine

Caffeine improves lung function in people with asthma for up to 4 hours.13 The main implication of this finding is that drinking coffee before a spirometry test may give a misleading result.

A meta-analysis found that it was not possible to conclude whether caffeine improves asthma symptoms.13 Some small studies have reported that caffeine improves exercise-induced bronchoconstriction.4 The dose needed to improve symptoms may be so high that it is associated with intolerable adverse effects (e.g. agitation, tremor, gastrointestinal upset, increased heart rate and blood pressure).13

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Vitamin D

A causal relationship between vitamin D deficiency and asthma symptoms or poor asthma control has not been established.8 However, very limited evidence suggests vitamin D may be protective against flare-ups.8

A single small randomised controlled trial in children with newly diagnosed asthma who were sensitised only to house dust mite, reported that vitamin D supplementation reduced the risk of asthma flare-ups triggered by acute respiratory infections.23 Another recent study failed to show any decrease in the rate of asthma flare-ups with vitamin D supplementation, although exploratory analysis of the results suggested that vitamin D supplementation a reduced the rate of asthma flare-ups only in adults who had an increase in circulating vitamin D levels after supplementation.24

Overall, there is not enough high-quality evidence to recommend routine vitamin D supplementation in asthma management.

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Dietary effects on risk of developing asthma

Factors associated with reduced risk of developing asthma

In observational studies, various dietary factors have been associated with reduced asthma risk or better lung health, but causal links are unproven:

  • A ‘Mediterranean’ diet (high in fish, fruits and vegetables) is associated with reduced risk of wheeze and asthma in childhood.25
  • Regular consumption of fish, especially oily fish, has been associated with lower risk of bronchial hyperresponsiveness or current asthma in Australian children2627
  • Children who reported eating fruit more than once a day had higher lung function than children who reported never eating fruit in a UK cross-sectional study.28

Factors associated with increased risk of developing asthma

In observational studies, various dietary factors have been associated with increased asthma risk, but causal links are unproven:

  • Consumption of fast foods has been associated with increased risk of developing asthma in children.293031
  • A ‘Westernised’ diet has been associated with increased asthma risk, compared with an ‘Asian’ diet.32
  • High soft drink consumption has been associated with higher prevalence of asthma and COPD.33
  • Reduction in fresh fruit intake over a 7-year period has been associated with decline in lung function in adults.34

Further research is needed to determine if these associations are due to causal links between food choices and asthma risk, and randomised controlled trials are needed to show whether changes in eating patterns can improve asthma control or reduce the risk of developing asthma.

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References

  1. Wood LG, Garg ML, Gibson PG. A high-fat challenge increases airway inflammation and impairs bronchodilator recovery in asthma. J Allergy Clin Immunol. 2011; 127: 1133-40. Available from: http://www.jacionline.org/article/S0091-6749(11)00125-4/fulltext
  2. Wood LG, Garg ML, Smart JM, et al. Manipulating antioxidant intake in asthma: a randomized controlled trial. Am J Clin Nutr. 2012; 96: 534-43. Available from: http://www.ncbi.nlm.nih.gov/pubmed/22854412
  3. Ardern KD, Ram FS. Tartrazine exclusion for allergic asthma. Cochrane Database Syst Rev. 2001; Issue 4: CD000460. Available from: http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD000460/full
  4. National Asthma Council Australia. Asthma and complementary therapies. National Asthma Council Australia, Melbourne, 2012. Available from: http://www.nationalasthma.org.au/publication/asthma-complementary-therapies-hp
  5. Pogson ZE, Antoniak MD, Pacey SJ, et al. Does a low sodium diet improve asthma control? A randomized controlled trial. Am J Respir Crit Care Med. 2008; 178: 132-8. Available from: http://www.atsjournals.org/doi/full/10.1164/rccm.200802-287OC
  6. Zhou Y, Yang M, Dong BR. Monosodium glutamate avoidance for chronic asthma in adults and children. Cochrane Database Syst Rev. 2012; 6: CD004357. Available from: http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD004357.pub4/full
  7. Hasselmark L, Malmgren R, Zetterstrom O, Unge G. Selenium supplementation in intrinsic asthma. Allergy. 1993; 48: 30-6. Available from: http://www.ncbi.nlm.nih.gov/pubmed/8457023
  8. Paul G, Brehm JM, Alcorn JF, et al. Vitamin D and asthma. Am J Respir Crit Care Med. 2012; 185: 124-32. Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3297088/
  9. Rowe BH, Camargo CA. The role of magnesium sulfate in the acute and chronic management of asthma. Curr Opin Pulm Med. 2008; 14: 70-6. Available from: http://www.ncbi.nlm.nih.gov/pubmed/18043278
  10. Shaheen SO, Newson RB, Rayman MP, et al. Randomised, double blind, placebo-controlled trial of selenium supplementation in adult asthma. Thorax. 2007; 62: 483-490. Available from: http://thorax.bmj.com/content/62/6/483.long
  11. Sur S, Camara M, Buchmeier A, et al. Double-blind trial of pyridoxine (vitamin B6) in the treatment of steroid-dependent asthma. Ann Allergy. 1993; 70: 147-52. Available from: http://www.ncbi.nlm.nih.gov/pubmed/8430923
  12. Thien FC, De Luca S, Woods RK., Abramson MJ. Dietary marine fatty acids (fish oil) for asthma in adults and children. Cochrane Database Syst Rev. 2002; Issue 2: CD001283. Available from: http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD001283/full
  13. Welsh EJ, Bara A, Barley E, Cates CJ. Caffeine for asthma. Cochrane Database Syst Rev. 2010; Issue 1: CD001112. Available from: http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD001112.pub2/full
  14. Mickleborough TD, Murray RL, Ionescu AA, Lindley MR. Fish Oil Supplementation Reduces Severity of Exercise-induced Bronchoconstriction in Elite Athletes. Am J Respir Crit Care Med. 2003; 168: 1181-1189. Available from: http://www.atsjournals.org/doi/full/10.1164/rccm.200303-373OC
  15. Mickleborough TD, Lindley MR, Ionescu AA, Fly AD. Protective effect of fish oil supplementation on exercise-induced bronchoconstriction in asthma. Chest. 2006; 129: 39-49. Available from: http://journal.publications.chestnet.org/article.aspx?articleid=1084219
  16. Pogson Z, McKeever T. Dietary sodium manipulation and asthma. Cochrane Database Syst Rev. 2011; Issue 3: CD000436. Available from: http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD000436.pub3/full
  17. National Asthma Council Australia. Asthma and allergy. National Asthma Council Australia, Melbourne, 2012. Available from: http://www.nationalasthma.org.au/publication/asthma-allergy-hp
  18. Kazaks AG, Uriu-Adams JY, Albertson TE, et al. Effect of oral magnesium supplementation on measures of airway resistance and subjective assessment of asthma control and quality of life in men and women with mild to moderate asthma: a randomized placebo controlled trial. J Asthma. 2010; 47: 83-92. Available from: http://www.ncbi.nlm.nih.gov/pubmed/20100026
  19. Hill J, Micklewright A, Lewis S, Britton J. Investigation of the effect of short-term change in dietary magnesium intake in asthma. Eur Respir J. 1997; 10: 2225-9. Available from: http://erj.ersjournals.com/content/10/10/2225.abstract
  20. Fogarty A, Lewis SA, Scrivener SL, et al. Oral magnesium and vitamin C supplements in asthma: a parallel group randomized placebo-controlled trial. Clin Exp Allergy. 2003; 33: 1355-9. Available from: http://www.ncbi.nlm.nih.gov/pubmed/14519140
  21. Gontijo-Amaral C, Ribeiro MA, Gontijo LS, et al. Oral magnesium supplementation in asthmatic children: a double-blind randomized placebo-controlled trial. Eur J Clin Nutr. 2007; 61: 54-60. Available from: http://www.nature.com/ejcn/journal/v61/n1/full/1602475a.html
  22. Bede O, Suranyi A, Pinter K, et al. Urinary magnesium excretion in asthmatic children receiving magnesium supplementation: a randomized, placebo-controlled, double-blind study. Magnes Res. 2003; 16: 262-70. Available from: http://www.jle.com/en/revues/bio_rech/mrh/e-docs/00/03/FD/CE/article.phtml
  23. Majak P, Olszowiec-Chlebna M, Smejda K, Stelmach I. Vitamin D supplementation in children may prevent asthma exacerbation triggered by acute respiratory infection. J Allergy Clin Immunol. 2011; 127: 1294-6. Available from: http://www.jacionline.org/article/S0091-6749(10)01957-3/fulltext
  24. Castro M, King TS, Kunselman SJ, et al. Effect of vitamin D3 on asthma treatment failures in adults with symptomatic asthma and lower vitamin D levels: the VIDA randomized clinical trial. JAMA. 2014; 311: 2083-91. Available from: http://jama.jamanetwork.com/article.aspx?articleid=1873132
  25. Nagel G, Weinmayr G, Kleiner A, et al. Effect of diet on asthma and allergic sensitisation in the International Study on Allergies and Asthma in Childhood (ISAAC) Phase Two. Thorax. 2010; 65: 516-22. Available from: http://thorax.bmj.com/content/65/6/516.long
  26. Peat JK, Salome CM, Woolcock AJ. Factors associated with bronchial hyperresponsiveness in Australian adults and children. Eur Respir J. 1992; 5: 921-9. Available from: http://www.ncbi.nlm.nih.gov/pubmed/1426199
  27. Hodge L, Salome CM, Peat JK, et al. Consumption of oily fish and childhood asthma risk. Med J Aust. 1996; 164: 137-40. Available from: http://www.ncbi.nlm.nih.gov/pubmed/8628130
  28. Cook DG, Carey IM, Whincup PH, et al. Effect of fresh fruit consumption on lung function and wheeze in children. Thorax. 1997; 52: 628-633. Available from: http://thorax.bmj.com/content/52/7/628.abstract
  29. Hijazi N, Abalkhail B, Seaton A. Diet and childhood asthma in a society in transition: a study in urban and rural Saudi Arabia. Thorax. 2000; 55: 775-779. Available from: http://thorax.bmj.com/content/55/9/775.full
  30. Wickens K, Barry D, Friezema A, et al. Fast foods - are they a risk factor for asthma?. Allergy. 2005; 60: 1537-41. Available from: http://onlinelibrary.wiley.com/doi/10.1111/j.1398-9995.2005.00945.x/full
  31. Huang SL, Lin KC, Pan WH. Dietary factors associated with physician-diagnosed asthma and allergic rhinitis in teenagers: analyses of the first Nutrition and Health Survey in Taiwan. Clin Exp Allergy. 2001; 31: 259-64. Available from: http://www.ncbi.nlm.nih.gov/pubmed/11251627
  32. Carey OJ, Cookson JB, Britton J, Tattersfield AE. The effect of lifestyle on wheeze, atopy, and bronchial hyperreactivity in Asian and white children. Am J Respir Crit Care Med. 1996; 154: 537-40. Available from: http://www.ncbi.nlm.nih.gov/pubmed/8756835
  33. Shi Z, Dal Grande E, Taylor AW, et al. Association between soft drink consumption and asthma and chronic obstructive pulmonary disease among adults in Australia. Respirology. 2012; 17: 363-9. Available from: http://onlinelibrary.wiley.com/doi/10.1111/j.1440-1843.2011.02115.x/full
  34. Carey IM, Strachan DP, Cook DG. Effects of changes in fresh fruit consumption on ventilatory function in healthy British adults. American journal of respiratory and critical care medicine. 1998; 158: 728-33. Available from: http://www.atsjournals.org/doi/full/10.1164/ajrccm.158.3.9712065