Evidence for Combination Therapy
By Jordan Robertson
This article reviews the evidence supporting the integration of nutritional supplements, such as vitamin D, magnesium, and fish oil, in asthma management. Learn how naturopathic approaches can enhance control and reduce hospitalizations by co-treating patients with these interventions.
Co-Treating Asthma Patients with Supplements
The evidence for the use of integrative medicine in asthma management reveals that:
- There is a large body of evidence that perinatal health and supplementation changes the incidence of asthma in offspring 1,2,3
- Early life exposures and health influence the incidence of asthma. 4
- Viral infections increase the risk of asthma exacerbation and hospitalizations.
- Adult health factors, including BMI5 and nutrient intake, influence asthma control and quality of life.6,7
While asthma was once considered a “luck of the draw” condition, current research highlights the interplay between genetics and health exposures–both positive and negative–that influence both the incidence and severity of asthma.
The management of asthma conventionally has challenges. Adults with asthma often have poor compliance with long-acting medications, have seasonal variations in asthma control as a reflection of overlapping viral infections, and a patient’s underlying health status has an impact on their asthma control. While not the primary focus of this article, naturopathic doctors can improve asthma outcomes by addressing patient compliance with long-acting beta-agonists – a common issue that often results in poorly controlled asthma and excessive use of short-acting inhalers use.8
We can have confidence in the use of specific nutritional supplements in both children and adults with asthma who are already medicated with long and short-acting steroids. Studies on asthma always permit medication use concurrently with the treatments being studied; it would be unethical not to. This means that every intervention study on naturopathic care is examined using drug therapy. This establishes not only safety but also helps with an understanding of the magnitude of benefits supplements can have. If patients are already medicated, we understand our additional value in the average patient looking for collaborative, not alternative, care.
This article summarizes the evidence on using nutritional supplements for asthma and provides context for integrating these solutions into your treatment plans for asthma patients.
Supplements with Evidence-Based Benefits for Asthma
Vitamin D
Key findings
- Vitamin D deficiency increases the risk of viral infections, which exacerbate asthma.
- Vitamin D supplemented longer than 6 months reduces hospitalizations from exacerbations.
- Children and adults with asthma have been shown to have lower levels of vitamin D than controls.
Studies have shown that children and adults with asthma have lower vitamin D status, and there is a link between vitamin D status and asthma exacerbations, likely due to the impact of RSV and respiratory infections. Children with vitamin D deficiency are more likely to have severe RSV and hospitalizations for RSV9, and patients with low vitamin D have higher hospitalization for COVID-19, which is a common trigger for acute asthma.10 Vitamin D supplementation in children reduces the risk of hospitalization of RSV11 and vitamin D supplementation reduces the risk of complications and hospitalization of COVID-19 in all patients.12
The trials on vitamin D and asthma that show promise are conducted longer than 6 months13 and are suspected to reflect seasonal variation in viral incidence. A study is needed to bridge RSV or flu season to see a positive outcome. When supplementing vitamin D in asthma patients, the expected result is reduced hospitalizations and severe asthma episodes connected to viral illness14, with most studies not showing significant changes in lung function or FEV1 scores.
Magnesium
Key findings
- Oral magnesium improves asthma-related quality of life and lung function.
- IV magnesium may be used in hospital settings in patients who do not respond to other emergency measures.
- Nebulized magnesium does not show benefit over other options at this time.
There are case reports of using magnesium for asthma as early as the 1960s, and there is a strong story about the biological plausibility of magnesium in reducing airway constriction. Research has generally focused on IV magnesium sulfate in emergencies and nebulized magnesium, with very few trials including oral magnesium citrate. Magnesium research has typically examined IV or inhaled magnesium as a rescue treatment in patients who have failed initial emergency medication options.15
To date, only one IV magnesium study has been conducted outside of an urgent care center. The trial was conducted in an acute hospital-like setting and, similar to the other studies on IV magnesium, was administering treatment for an acute asthma attack. The practicality and utility of IV magnesium in otherwise well-controlled patients don’t have enough research to support routine use. Nebulized magnesium has been recently studied in combination with salbutamol with no effect16,17 and against salbutamol in a meta-analysis, which also has no effect.18
Despite the lackluster results of IV and inhaled magnesium, the few trials on oral magnesium show benefits in lung function (FEV1) and asthma-related quality of life in children and adults.19 There appears to be a minimum dose required for benefit, with studies showing improvement only when the dose of magnesium citrate exceeded 340 mg and when the studies were conducted for 6 months or longer. Unfortunately, these studies did not track medication use, but there was a significant impact on patient-important outcomes such as quality of life.20,21
Fish Oil
Key Findings
- Fish oil in children may reduce the risk of allergy-induced asthma.
- A higher dose of fish oil (>4 g) reduces lung inflammation and improves FEV1 in adults.
- Patients with lower baseline status may benefit most from fish oil.
The patients with the most significant impact from supplemental fish oil are the most genetically at risk for the development of asthma. There are studies using fish oil from birth to decrease the effects of environmental exposures such as pollution and reduce the risk of asthma in genetically at-risk patients with atopic parents.4,22 23 We also see patterns of improved asthma control in adolescents and adults with higher dietary omega-3 intake.24,25
Intervention trials in asthma show reduced lung inflammation26 and improved FEV1 in exercise-induced asthma in adults.27 Many of the intervention trials with fish oil use higher dosing, with doses reaching 4 grams of combined EPA/DHA. Green-lipped mussels, as a source of omega-3, have also been shown to improve lung function when supplemented.28
At this time, despite emerging evidence that there may be particular asthma patients who benefit more from fish oil, we don’t have a reliable way of understanding asthma phenotypes to make treatment decisions. The recommendation is to supplement all patients with omega-3 to achieve adequate status based on dietary baseline intake and consider higher dosing in patients that fit a genetically susceptible profile. Studies on exercise-induced asthma are typically 3 weeks in duration, which gives clinicians a time frame to expect improvement before discontinuing this treatment option.
Summary and Practice Considerations
Naturopathic Doctors are uniquely positioned to help patients gain control over their asthma through a strong history of taking, medication education compliance support, and supplementing to reduce the risk of viral infections and improve asthma-related quality of life.
For patients experiencing symptoms despite regular inhaler use, consider the following:
- Magnesium Citrate 340 mg daily
- Fish Oil: 2-4 grams of combined EPA/DHA per day
- Vitamin D: dosage to correct deficiency
Monitoring viral exacerbations, hospitalizations, and asthma-related quality of life over 6 months can help practitioners and patients understand the value of nutritional supplementation and medication regimes for the long-term management and control of asthma.
Dr. Jordan Robertson ND is on a mission to create a standard of care of evidence based naturopathic medicine while reducing the unpaid-research-labour of naturopathic clinicians. She is the founder of The Confident Clinician, a clinical decision making tool and database built specifically for Naturopathic Doctors. She is a graduate of CCNM (2008) and has a 15 year career teaching critical appraisal, research in integrative medicine and clinical nutrition at McMaster University Canada. Jordan can be reached at hello@theconfidentclinicianclub.com