Is Fast Food Causing Increased Childhood Asthma and is the Mediterranean Diet the Answer?

In the 1980s a young mother reported to me that her son's asthma improved with changing his diet: increasing fruits and vegetables-and decreasing burgers. Back then I had very little medical research to confirm her findings. Her findings continue to intrigue me.

Recently medical researchers are confirming her experience as more than an isolated anecdote.

The alarming increase of childhood asthma in the U.S.-up to 160% in children age 4 or younger from 1980 to 1994-has spurred interest in the causes. With recognition of the epidemic of childhood obesity, diet is increasingly recognized as a potential contributor to asthma.

So what role may diet play in asthma?

The recent medical literature has some interesting results:

Diet high in burgers reportedly associated with increased asthma risk

In June 2010 the ISAAC (International Study on Allergies and Asthma in Childhood) Phase Two Study Group reported their results of studying 50,000 children in 20 countries.

In the journal Thorax, the researchers report that "Overall, more frequent consumption of fruit, vegetables and fish was associated with a lower lifetime prevalence of asthma, whereas high burger consumption was associated with a higher lifetime asthma prevalence."

They found an association with diet, and reported the Mediterranean Diet, which is high in fish, vegetables and fruit, may decrease the risk of asthma.

Is the Mediterranean Diet Associated With Lowered Asthma Risk?

The ISAAC Phase Two Study Group also reported in Thorax, "these results provide further evidence that adherence to a 'Mediterranean Diet' may provide some protection against wheeze and asthma in childhood."

Interestingly, a study of Spanish schoolchildren using the same ISAAC questionnaire found no protection from a Mediterranean Diet on the prevalence or severity of childhood asthma. A study comparing the two studies to see why the results are so different might be helpful.

A study from Sweden of older people (ages 16 to 69) also confirmed that a diet high in fresh fruits and fish lowered the risk of asthma.

Another interesting report is a review of the literature published in Allergy and Asthma Proceedings three months before the ISAAC report. Its authors concluded there was no conclusive evidence of the role of diet in asthma development.

What about olive oil in the diet and asthma?

Researchers from Chile in April 2010 report that olive oil-but not the Mediterranean Diet-consumed during pregnancy prevented wheezing during the baby's first year of life.

What's the bottom line?

Before making changes in diet, it's best to consult with your child's doctor or your doctor. He or she will have the most up-to-date information and how it applies to your individual situation.

SOURCES:

Asthma Data Fact Sheet - Asthma Statistics. National Institutes of Health. National Heart, Lung, and Blood Institute.

Kate Kelland. "Burger diet linked to higher childhood asthma risk." Medline Plus: Reuters Health. June 2, 2010.

Gabriele Nagel, Gudrun Weinmayr, Andrea Kleiner, Luis Garcia-Marcos, David P Strachan, the ISAAC Phase Two Study Group. "Effect of diet on asthma and allergic sensitisation in the International Study on Allergies and Asthma in Childhood (ISAAC) Phase Two." Thorax 2010;65:516-522 doi:10.1136/thx.2009.128256

Gonzalez Barcala FJ, Pertega S, BGonzalez MA, Lopez Silvarrey A. "Mediterranean diet and asthma in Spanish schoolchildren." Pediatric Allergy and Immunology. 2010 Jun 14. [Epub ahead of print]

Uddenfeldt M, Janson C, Lampa E, Leander M, Norbäck D, Larsson L, Rask-Andersen A. "High BMI is related to higher incidence of asthma, while a fish and fruit diet is related to a lower- Results from a long-term follow-up study of three age groups in Sweden." Respiratory Medicine. 2010 Feb 17. [Epub ahead of print]

Arvaniti F, Priftis KN, Panagiotakos DB. "Dietary habits and asthma: a review." Allergy and Asthma Proceedings. 2010 Mar;31(2):e1-10.

Castro-Rodriguez JA, Garcia-Marcos L, Sanchez-Solis M, Pérez-Fernández V, Martinez-Torres A, Mallol J. "Olive oil during pregnancy is associated with reduced wheezing during the first year of life of the offspring." Pediatric Pulmonology. 2010 Apr;45(4):395-402.