Preventing food allergies in children - a change of strategy?

According to the Centers for Disease Control and Prevention (CDC) in the United States in 2007 around 3 million children under 18 had food allergies - a rise of 18% since 1997.

The CDC says in 2006 about 6.8 million children suffered from some sort of allergy and for some reason which remains unclear there are a growing number of children with allergies to foods such as peanuts, eggs and fish and these affected children are two to four times as likely to have related conditions such as asthma or other allergies.

Experts say while improvements in diagnosis could partly explain the increase, allergies do appear to be more common at present than they were a generation ago.

A suspected culprit in the increase in both food and environmental allergies is thought to be the 'hygiene hypothesis' where the current vogue for scrupulous cleanliness removes the immune system benefits from early exposure to bacteria.

Some experts suggest that the more hygienic the environment, the more allergies there will be while others believe that a lack of exposure to specific foods in infancy may result in allergies to those foods later on.

Once an allergy develops the only option is to manage the symptoms and at present how to prevent allergies from developing in the first place, remains a dilemma.

Research suggests that the causes of allergies are a complex mixture of genetics and environment but a new study of 8,600 Jewish children in the United Kingdom and Israel may ultimately provide some insight.

The British and Israeli researchers found that the early consumption of peanuts in infancy was linked with a low prevalence of peanut allergy.

The researchers say despite guidelines recommending avoidance of peanuts during infancy in the UK, Australia, and, until recently, North America, peanut allergy continues to increase in these countries.

They set out to determine the prevalence of peanut allergy among Israeli and UK Jewish children and the relationship with peanut consumption by mothers and children.

The study involved 5,171 schoolchildren in the UK and 5,615 in Israel and included a questionnaire on peanut consumption and weaning involving 77 infants in the UK and 99 in Israel.

The researchers found that the UK Jewish children had 10 times more peanut allergies than the Israeli infants and the difference came down to the fact that the Israeli infants consume peanut in high quantities in the first year of life, whereas UK infants avoid peanuts.

They say their results raise the question of whether early introduction of peanut during infancy, rather than avoidance, will prevent the development of peanut allergies and that with food allergies, there might be a benefit from early exposure.

A proposed clinical trial by researchers in the UK is currently recruiting 480 children ages 4 months to 10 months who will be randomly assigned to consume or avoid peanuts but these results are not expected for about five years.

While there is at present some hope in oral immunotherapy, where gradually increasing an allergic person's exposure to offending foods, might help ward off allergies, that therapy is still to be proven.

The American Academy of Allergy, Asthma and Immunology now recommends that vegetables, rice, meat, and fruit should be added to a child's diet between 6 months and one year so that problem foods can be easily identified.

The Academy says thereafter a child should try milk, wheat, corn, citrus fruit, and soy and at age 2, eggs and at 3, fish and peanuts.

Experts say children with parents who have allergies should be regarded as high risk but breastfeeding for the baby's first four to six months of life offers some protection.

The British study is published in November issue of The Journal of Allergy and Clinical Immunology.