What is it in the Environment that triggers Peanut Allergy?
In general I haven’t given much thought about the heritability of my son’s peanut allergy, since food allergies are not an issue in my family or my husband’s. I ignored all of the advice to avoid eating peanuts while pregnant (though I am quite convinced there is more to it than this) and barely knew how allergies affected one’s health before the diagnosis.
Lately, there has been some great new information and theories, though some conflicting, that grabbed my attention to understand on a deeper level how someone “gets” a peanut allergy. Of all the studies listed here, none seem to rule out the environment and an unexplainable mystery factor. Actually, most researchers suggest that there is an environmental factor at play, which they cannot quite pinpoint.
According to a recent article in February from the New Yorker, “From an evolutionary-biology point of view, food allergy makes no sense at all,” Dr. Sicherer, a pediatric allergist at Mt Sinai in New York, said. “It seems pretty clear that food allergy is a condition that resulted from the environment we created.” “Basically, we are all in limbo, he added. “Even the experts are not certain what to advise” regarding whether to avoid or not avoid certain types of foods in the early years in order to prevent allergies from developing.
According to BBC news article posted on March of 2011, scientists claim a peanut allergy “gene flaw” link. “A gene defect that can triple the risk of a child developing an allergy to peanut has been identified”, scientists have claimed. Only 20% of peanut allergy cases, however, were found to have this Filaggrin gene defect, and between 4% to 11% had the gene defect, yet, were not allergic to peanuts.
Identical twins, who share all 25,000 genes, were used in researching whether or not there is a biological program for having a peanut allergy. A study from 2000 from the Elliot and Roslyn Jaffe Food Allergy Institute, Mt Sinai School of Medicine, concluded that there is a higher rate of peanut allergy among identical twins, strongly suggesting a genetic influence. Yet, not all identical twins having identical genes had a peanut allergy.
Information by geneticist, Dr. Barry Star (Stanford University) states that while peanut allergies tend to run in families, in 36% of the cases this is not true. Thus, there is a strong environmental role which remains unknown.
And lastly, a newly released book, The History of the Peanut Allergy Epidemic by Heather Fraser, gives us a new perspective of why some “get” a peanut allergy. She places the increase in allergies, beginning about 20 years ago, at the same time of changes in vaccination combinations, ingredients and schedules. Fraser clearly states this as a possible environmental contributor.
All seem to have one common theme, which is environment cannot be ruled out. Uncovering this mystery environmental factor will hopefully lead us to more food allergy prevention and putting a cap on the growing numbers of peanut allergy and food allergy in general.
Debbie at Peanut Free Sweet Tooth