How Can Diet Affect Asthma Prevention, Outcomes, and Treatment?

Asthma cases continue to rise and affect millions of people around the world. In 2019, 262 million people were affected by asthma, and the condition contributed to 455,000 deaths.¹ While treatment options like inhalers can help control symptoms, patients with asthma are also encouraged to avoid potential triggers.

Though there is no conclusive evidence of diet and nutrition directly impacting asthma outcomes and risk, studies have suggested that certain dietary choices may correlate with reduced or increased risk of symptoms. In addition, many asthma cases stem from people and countries with lower socioeconomic status. This means cases may be underdiagnosed and healthier foods may not be as readily available for many. Are there certain diets clinicians should recommend to patients seeking to improve their asthma symptoms?

Reducing Asthma Risk

Despite there being no direct link between nutrition and asthma, obesity is seen as a significant risk factor in asthma development and outcomes.² As a result, a healthier diet and lifestyle may be recommended to those looking to reduce asthma risk and symptom burden.

A diet rich in fruits and vegetables has shown potential to reduce the risk of asthma; namely, vegetables with high levels of vitamin A like carrots, leafy greens, broccoli, and sweet potatoes. It has also been suggested that more vitamin D may help reduce asthma attacks in children, so parents may want to incorporate more milk, eggs, and salmon into their childrens’ diet.

A 2020 study in Nutritional Reviews looked at the role of nutrition in asthma development and treatment, and found that plant-based diets with whole grains also correlated positively with reduced risk of asthma.³ Plant-based diets with more fruits and vegetables and less meat and fat may also help patients with asthma by increasing anti-inflammatory markers, in part due to the antioxidants in these foods helping to reduce inflammation in the airway. The researchers also noted that fiber intake showed an association with better lung function.

Asthma Risk Factors

The researchers also posited that the increase in asthma cases could be due in part to Western diets that are much heavier in animal products than the plant-based diets mentioned previously. These diets are much higher in fat and lower in fiber, both of which are associated with greater airway inflammation and poorer lung function. High fat diets, in particular, can alter gut bacteria in a way that causes significant inflammation.

While milk and eggs have vitamin A, too high of a dairy intake is also associated with asthma development. This is also true of foods with sulfites, such as wine, dried fruits, and pickled foods.² In addition, patients should avoid eating foods they are allergic to, so as to avoid triggering asthma symptoms.

References

1. Asthma. World Health Organization. https://www.who.int/news-room/fact-sheets/detail/asthma. Updated May 11, 2022. Accessed August 2, 2022.

2. Diet recommended for people with asthma. Healthline. https://www.healthline.com/health/asthma/asthma-diet. Reviewed April 30, 2019. Accessed August 2, 2022.

3. Alwarith J, Kahleova H, Crosby L, Brooks A, Brandon L, Levin SM, Barnard ND. The role of nutrition in asthma prevention and treatment. Nutr Rev. 2020 Nov 1;78(11):928-938. doi: 10.1093/nutrit/nuaa005. PMID: 32167552; PMCID: PMC7550896.