Asthma is a condition characterised by constriction in the airways of the lungs. Inflammation in the airways is another common feature, and this may also be accompanied by the presence of some mucus that can obviously add to the obstruction of airflow in and out of the lungs. Common symptoms of active asthma include shortness of breath, wheezing and coughing.
There are many potential triggers for asthma. Some of these can come from within the body (e.g. food), while others can come from the outside. Outside triggers include ‘airborne’ agents such as pollen, mold spores, pollution, and the faeces of the house dust mite.
I was interested to read about a nutritionally oriented approach that was tried in a group of house dust mite-sensitive asthmatics. The treatment under test was a blend of omega-3 fats at a dose of 0.6 g per day. The study lasted just 5 weeks. In the last two weeks of the study, the participants were challenged each day with house dust mite ‘allergen’.
The study participants were monitored with a number of tests including the amount of the gas nitric oxide they exhaled. This test provides an indirect measure of the amount of inflammation in the airways. Despite the relatively low dose of omega-3 used in this study and quite short duration, the active treatment (compared to placebo) led to significantly lower levels of exhaled nitric oxide. In other words, taking omega-3 appeared to reduced inflammation in the lungs of these asthmatics. This is consistent with prior knowledge that we have regarding omega-3 fats in relation to their natural anti-inflammatory properties.
Allergic reactions to house dust mite faeces (or other allergens) typically involve white blood cells known eosinophils. Eosinophil counts in the blood generally go up during allergic responses in the body. The researchers found that eosinophil counts were lower in those taking the omgea-3 supplement compared to those taking placebo. Other markers of disease activity were lower also.
What this study suggests is that omega-3 supplementation may be beneficial for asthmatics, particularly those suffering from allergic asthma.
While interesting and relevant, I think, what this study does not tell us is if omega-3 supplementation actually helped the symptoms of the asthmatics being tested. However, there has previously some work that suggests omega-3 supplementation may help in this regard. In a study published in 2000, asthmatic children were treated with a mix of EPA and DHA (two omega-3 fats found in oily fish) or placebo (olive oil) for a period of 10 months. The total daily dose of omega-3 fats was in the order of 30 mg per kg per day.
Omega-3 supplementation led to a significant reduction in asthma symptom scores. This study provides at least some evidence that omega-3 supplementation has the potential to control asthma.
References:
1. Schubert R, et al. Effect of n-3 Polyunsaturated Fatty Acids in Asthma after Low-Dose Allergen Challenge. Int Arch Allergy Immunol 2008;148(4):321-329.
2. Nagakura et al. Dietary supplementation with fish oil rich in omega-3 polyunsaturated fatty acids in children with bronchial asthma. Eur Resp J. 2000;16(5):861-865.
