Asthma is a complex and poorly understood disease. It is likely caused by an alliance of genetic and environmental factors. Evidence suggests that our diet is one of these environmental factors. The diets of our ancestors consisted mostly of nuts, fruits, vegetables, and limited amounts of unprocessed meats. Post-industrialization, and particularly in developed countries, our diets are now high in saturated fat (i.e. fried foods and processed meats), sugar, and processed grains. Supportively, we see that asthma prevalence rates are highest in developed countries (e.g. U.S., Ireland, United Kingdom), while rates area rising in the developing world as they adapt to a Western lifestyle and diet. Lab experiments with mice demonstrate that high fat and low fiber diets worsen airway inflammation.
The reasons to changing diets goes beyond improving asthma control. A Western diet is also known to cause heart disease, diabetes, obesity, and recently, has been connected to chronic obstructive pulmonary disease (COPD). It is indicated in the development of complex inflammatory conditions, such as inflammatory bowel disease.
Nonetheless, with respect to asthma, here are my recommendations:
Adapt a diet high in fruits and vegetables, nuts/seeds, and oily fish, as evidence suggests it could be helpful. I typically recommend this diet as the starting point. I also suggest increasing the amount of foods high in Omega-3, while at the same time decreasing those high in Omega-6, i.e. transitioning to anti-inflammatory fats. This means eating more tree nuts and fatty fish, while avoiding or eating less peanuts, processed meats, poultry and eggs.
I do not recommend avoiding dairy, particularly in children. Cow’s milk is high in Vitamin D and Omega-3 (if fortified). Despite common beliefs, there has never been evidence that cow’s milk or dairy products increase mucous production or worsen asthma. In fact, several blinded studies (‘blinded’ means the subject tested is blinded to the food ingested) show that ice cream ingestion made no difference on asthma symptoms or mucous production.
Reduced processed meats. This includes hot dogs and hamburgers. We obviously have to live our lives, and this doesn’t mean depriving your child a burger among friends. But while countless studies prove these foods are particularly inflammatory, we ask that you don’t eat them every day.
Adopting a diet similar to that of the Mediterranean diet could prove to be very efficacious in helping with the inflammation associated with asthma while also imbuing other beneficial side effects.