Now comes word that early exposure to peanuts may actually prevent peanut allergies. Researchers looked at peanut exposure and allergies in two different Jewish populations, about 5,000 in the UK and 5,000 in Israel. Apparently women in the UK, but not Israel, are told not to eat peanuts (and nuts) during pregnancy and to wait until kids are 3 to feed them nuts. This recommendation assumes that early exposure contributes to nut allergies. So which population do you think has more peanut allergies? The kids in the UK.
So this should be taken as one of many conflicting studies. There are several holes in this research, namely that it's a population-based prevalence study and that there are any number of factors that may account for the difference in allergies although researchers did include many control variables. I'm not sure they assessed factors like family history of allergies. Still, they found kids in the UK had 10 times the risk of developing nut allergies as did the kids in Israel. Sure, the risks were pretty low overall (1.85% vs. 0.17%). But it offers an intriguing possibility that other scientists are seriously considering these days: that there may be a window in which children should be exposed to nuts, a window before age 3. And that limiting early nuts might in fact increase nut allergies. In fact, I've been told that at a recent American Academy of Pediatrics conference many doctors shared this new viewpoint.
Let's hope someday soon we'll nail down the nut puzzle.
You can find the abstract for the study in the November issue of The Journal of Allergy and Clinical Immunology. But you'll have to pay to read the full article.