Fish oil reduces symptoms of exercise induced asthma

Fish oil can reduce the symptoms of exercise induced asthma to below the threshold for diagnosing it and at the same time lower the need for emergency medication according to the results of a trial carried out by Indiana University in Bloomington, USA.

The trial was a randomised double blind cross over study and involved 16 people who had mild to moderate asthma and who normally took medication on a daily basis to control it. During the trial those taking part were given either fish oil or a placebo for a period of three weeks. The dose of fish oil was quite high containing 3.2gr of Eicosapentaenoic acid (EPA) and 2gr of Docosahexaenoic acid (DHA).

Both at the beginning and at the end of the trial, the participants were subjected to lung efficiency tests and had their sputum analysed for pro inflammatory cells and markers. Those who were given fish oil showed improved lung efficiency of about 64% and reduced their need for emergency medication by around 31%. They also had a lower level of pro inflammatory cells and markers in their sputum. These promising results are believed to be due to the anti-inflammatory effect of the Omega 3 fatty acids that are present in fish oil.

What is exercise induced asthma?

After exercise and sometimes even during exercise, the airway passages in people with exercise induced asthma become inflamed and narrower resulting in decreased lung efficiency, often making it necessary to use inhalers. The constriction of the airways causes various symptoms including coughing, tightness across the chest, wheezing and shortness of breath. These symptoms generally start to ease off gradually over a period of half an hour or so following exercise.

No one really knows what causes it but it is thought to be triggered by the drying out and cooling of the airway passages which results in the cells releasing pro inflammatory chemicals which then causes a narrowing of the airways. Consequently, exercising in cool and dry conditions outdoors is more likely to result in an attack of asthma than physical activities such as swimming where the air is moist and warmer.

One major problem with exercise induced asthma is that it can be a barrier to exercise for many people, particularly youngsters who can be put off sport and other physical exercise because of it. It is also on the increase and the reason for this is thought to be linked to an increased consumption of Omega 6 fatty acids in the diet along with a reduction in the amount of Omega 3 fatty acids. Omega 6 is known to be pro-inflammatory whereas Omega 3 has anti-inflammatory properties and it is this difference in ratio that is thought to be responsible for a rise in a number of health problems.

Omega 6 is found in processed foods, vegetable oils, meats and dairy products so there is an abundance of them in our diet. The Omega 3 fatty acids EPA and DHA on the other hand are only found in oily fish or fish oil as plant sources of Omega 3 do not contain EPA and DHA, they are in the form of Alpha linolenic acid or ALA, but the problem with ALA is that our bodies cannot easily process it to produce EPA, which is the fatty acid best known for its anti inflammatory effects.

You would have to eat an awful lot of fish to get the same amount of EPA that is present in fish oil, which isn’t a good idea due to the potentially harmful toxins, including mercury, that are found in our fish. So, for this reason, fish oil offers a viable and safer alternative. Another point worthy of consideration is that long term use of medication for asthma can make it less effective and of course as with any medication there can also be unwanted side effects so if fish oil can reduce the need for medication and inhalers in people with exercise induced asthma, then that is exciting news indeed.


Fish oil is already known to offer both preventative and therapeutic health benefits for a number of conditions and so is an excellent supplement to promote good health in general. However, a word of caution, if you are thinking of trying fish oil supplements it is essential to opt only for the best quality fish oil known as pharmaceutical grade fish oil due to the potentially harmful toxins that can be present in lesser grade fish oils.