Allergy Prevention

It is better to prevent than to cure

– Peruvian proverb

Risk factors for development of allergy:

Cannot modify:

  • Genetics

Can modify:

  • allergenic diet
  • high household allergen exposure (dust-mite, cockroach, and dander levels)
  • environmental pollution
  • tobacco exposure

Food Allergy Prevention


Q: Can a pregnant woman’s diet influence the likelihood that she will have an allergic child?

A: One study has shown that Lactobacillus (friendly intestinal bacteria, a.k.a. probiotics) fed to mothers prenatally and newborn infants was effective in prevention of early atopic diseases in children at risk. Probiotic bacterias as live supplements are increasingly used in dairy foods and another study of infants fed lactobacillus-fermented milk and yogurt supports this as a method of allergy prevention. 

Another study found that a high fish diet (about 2 to 3 times per week) in pregnant women had a protective effect on their offspring. This was limited to women who did not breastfeed perhaps because the effects of the fatty acids in the diet were more apparent in this group. Pregnant women should be mindful of mercury levels in fish as well as other foods that they should avoid.

Q: Should a pregnant woman avoid certain foods?

A: It may be wise to avoid eating a high peanut diet since this allergy is usually lifelong and may be severe.  Some suggest avoiding peanuts altogether during pregnancy but this is a controversial topic.  Recent studies suggest that peanut avoidance during pregnancy is not an effective preventive measure.  General recommendations cannot be made but it may be wise for high risk families to avoid early exposure, even in the prenatal period.


Studies from several countries provide indirect evidence for the hypothesis that early exposure to viral infections, although triggering lower airway symptoms during early life, may have long-lasting protective effects. Children who were born into families with several, particularly older, siblings have been found to have a reduced risk of allergic sensitization and asthma at school age.Studies in children who had attended day care centers during infancy support this concept.2nd hand smoke is a risk factor for childhood asthma. Reducing exposure for children should have an impact on the incidence of asthma.

Limiting exposure to dust mites reduces dust mite allergy which is also a risk factor for asthma.

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