Asthma is a chronic inflammatory disease affecting the airways. Symptoms include coughing, shortness of breath, chest tightness and wheezing.
It’s still not entirely clear what causes asthma. It’s thought to develop due to a combination of factors such as our genetics, the environment we live in and other factors such as how our immune system develops from our time in the womb and throughout our lives.
Does diet play a role?
Research in recent years has started to look at environmental triggers for asthma development and exacerbations. One such environmental influence which has received a lot of attention is diet. We’re becoming more and more interested into how the food we eat affects us and various diseases and asthma is no different. Research is now emerging that nutrition can be an important tool in the tool box of asthma management and prevention from when a woman is pregnant and throughout the lifespan.
Anti-Inflammatory Diet/Mediterranean Diet
Diets with greater inflammatory effects have been associated with higher levels of inflammation and poorer asthma control. It’s important to remember that inflammation isn’t driven by one food but rather a collection of pro-inflammatory dietary components such as trans fats alongside low intakes of fibre, fruit and vegetables.
A Mediterranean style dietary pattern has commonly been praised for its health benefits and is commonly known as an anti-inflammatory diet. It originally received attention due to it being associated with lower mortality rates from coronary artery disease. It may also play a role in asthma management. The Mediterranean Diet focuses on foods such as oily fish and olive oil, which are high in monounsaturated and polyunsaturated fats which are known for their anti-inflammatory effects, along with fruit, vegetables and wholegrains which are rich in antioxidants and fibre.
Consumption of these foods has been associated with lower rates of asthma as well, less exacerbations of asthma as well as better asthma control, while conversely, diets low in fibre and high in trans and saturated fats are associated with worse asthma symptoms.
Low levels of Vitamin D have been reported in asthmatics. The primary source of vitamin D is sunlight with small amounts found in oily fish, egg yolk and fortified foods. However, it’s now known that the amounts obtained from sun and food isn’t sufficient to maintain optimal vitamin D levels. Vitamin D is mainly known for its role in bone health but it also plays a key role in our immune system. A 2016 Cochrane systematic review (this is one of the highest level reviews of lots of studies in the world of nutrition research) found that high dose vitamin D supplementation in children and adults with mild to moderate asthma aided in a reduction of the number of asthma attacks requiring steroid treatment and/or hospitalisation. Supplementing with 1000-3000IU vitamin D daily, aiming for the higher end in the winter months, is recommended for most people but those with asthma might get a particular benefit.
Turmeric has gained massive popularity over the last few years due to its suggested anti-inflammatory properties which are thought to be due to a component found in it called curcumin. Research into curcumin and asthma is also promising with trials showing reduced airway inflammation and mucous secretion with its supplementation.
Sulphites are an additive commonly used in food processing to preserve wine, dried fruit and meat. In some people with asthma, sulphites can trigger wheezing and shortness of breath so minimising or avoiding such additives might be a good idea.
Asthma is a complicated condition with many different causes and triggers. So there’s not going to be one thing that can cure it or manage it. But diet is one tool in the toolbox which may give us an insight into its development and management.