Protecting babies from highly allergenic foods and dust mites during their first year could prevent asthma during childhood, a new study suggests.

In a revolutionary study, led by Professor Hasan Arshad, a consultant in allergy at Southampton General Hospital, and published in the journal Thorax, researchers have discovered that a baby's risk of asthma is decreased by more than half if their contact with triggers of allergy from birth to 12 months is monitored.

Prof Arshad, who is also director of the David Hide Asthma and Allergy Research Centre on the Isle of Wight, said, "Although genetic links are arguably the most significant risk factor for asthma in children, environmental factors are the other critical component."

He notes that this study was small, however, it is significant because the result was over a 50 percent drop in the risk factor for asthma when control of a child's environment was introduced.

Arshad and his colleagues analyzed 120 patients with a family history of allergy who were found to be at high risk of allergy at birth 23 years ago. Their aim was to explore whether mothers who breastfeed and their kids who followed an exact diet, in combination with the use of vinyl mattress covers and pesticides to eliminate dust mites, had a decreased risk of developing asthma.

The diet included:
  • soy
  • fish and nuts
  • eggs
  • dairy products
Follow-ups were carried out at ages two, three, four, eight and 18 and revealed that just 11 percent of those in the prevention cohort had developed asthma by 18, while 27 percent of those who were naturally exposed to substances associated with allergic reactions had asthma.

By combining environmental and dietary avoidance during the first year of life - the development of asthma can be prevented during the first years and throughout childhood up to age 18 years.

Professor Arshad, who is also chair in allergy and immunology at the University of Southampton and is based at the NIHR Southampton respiratory biomedical research unit, emphasized an immediate need to reproduce these findings in a larger study.

He concluded:

"Our finding of a significant reduction in asthma using the dual intervention of dust mite avoidance and diet modification is unique in terms of the comprehensive nature of the regime, the length of follow-up and the size of the effect observed."

Allergies and asthma have been linked to a range of factors

Over the last thirty years there have been literally hundreds of studies on allergies and asthma, especially among children. The incidences of allergies and asthma among children have been growing steadily over the same period. The National Health Service (NHS), UK, says that approximately 5 in every 100 people live with asthma.

Nearly all patients with asthma also have some kind of allergy, possibly to food, dust, pollen, etc. One in every four people with hay fever develops asthma. Allergic reactions triggered by antibodies in the blood commonly lead to inflammation of the airways, which is associated with asthma.

The most common indoor allergens which affect the airways, and/or nose, throat and eyes (and sometimes skin) include animal proteins (mostly dog and cat allergens), cockroaches, fungi and dust mites.

Experts believe that the push towards energy-efficient homes has increased human exposure to many causes of asthma.

Among children, the most common foods that may trigger allergic reactions are wheat, soya, milk and eggs. Adults with allergies are more likely to be sensitive to types of fish, some shellfish, and tree nuts (including peanuts, almonds, walnuts, pistachios and Brazil nuts).

Below are examples of some interesting allergy and asthma studies: Written by Kelly Fitzgerald