Pediatric Newsletter #15: Food Allergies, Gluten, and Pizza

Welcome to the latest edition of my newsletter for parents about pediatric topics. In it I highlight and comment on new research, news stories, or anything else about children’s health I think will interest parents. In this particular issue I tell you about a couple of new findings about allergies in children, as well as some new information about gluten sensitivity. I have over 30 years of experience practicing pediatrics, pediatric critical care (intensive care), and pediatric emergency room care. So sometimes I’ll use examples from that experience to make a point I think is worth talking about. If you would like to subscribe, there is a sign-up form on the home page.

Big News About Peanut Allergies

This one made a big splash both in the medical news sites and in the general media. Peanut allergy is common. It has doubled in the past decade, now affecting between 1 and 3% of all children. And it can be a big deal for children who have it, even life-threatening. For years we recommended that children not be given peanut products early in life, especially if they are at risk (based on their other medical issues) for developing allergy. Unfortunately, avoiding peanuts in the first year of life doesn’t make a child less likely to develop the allergy. So what, if anything, can?

This recent, very well done study published in the prestigious New England Journal of Medicine is really ground-breaking. It took 4 to 11-month-old children at high risk for developing peanut allergy and divided them into 2 groups. One group got the “standard” approach — being told to avoid peanut exposure. The other group was fed peanuts 3 times per week. It was done in the form of either a peanut snack or peanut butter.

At age 5 years (the long follow-up time is a particularly strong feature of the study) the children who had been fed the peanuts had nearly a 90% reduction in the development of peanut allergy. This is a huge difference.

The study also was able to provide a scientific explanation for the difference. The children fed the peanuts developed protective antibodies that cancel out the ones that provoke the allergic response.

Washing Dishes by Hand May Reduce the Risk of Food Allergies

This report comes from Pediatrics, the journal of the American Academy of Pediatrics. There has been a long-standing theory about how allergies develop in children called the “hygiene hypothesis.”

The notion is that children, particularly in Western countries, are more prone to allergies (and asthma) because their exposure to microbes is delayed by our more sanitized environment.

In this study from Sweden, children in households that washed dishes by hand rather than using a dishwasher experienced a lower risk of subsequent allergies. The authors speculated that there was a causal association. They couldn’t prove that, but they also noted that early exposure to fermented foods and if the family bought food directly from farms also correlated with less allergies. I’m not totally convinced, but it is an interesting study worth thinking about. I expect to see more on the topic.

Does the Age at Which You Introduce Gluten Into Your Child’s Diet Affect Future Risk of Gluten Sensitivity?

Gluten sensitivity is in the news, with signs everywhere advertising “gluten free” as if this is always a good thing. I hear a lot of misconceptions about gluten sensitivity. Gluten is a protein found in grains such as wheat and barley. There is a condition, called celiac disease or sprue, in which a person can develop moderate or severe intestinal symptoms triggered by gluten. It is one of the eighty or so autoimmune diseases. The incidence of celiac disease in the US is about 0.7%. The risk of developing celiac disease is closely linked to a genetic predisposition to getting it. Importantly, if you don’t have the disorder, there is no benefit to eliminating gluten from your diet. In fact, the great majority of people who think they have sensitivity to gluten . . . don’t.

But for those children who do have a higher risk for developing celiac disease because of their genetic makeup it has long been a question if delaying gluten exposure will affect their chances of actually getting the disease. A good recent study gives an answer to that question, and the answer is no. There is no correlation.

If you think your child (or you) have problems with gluten there is a useful blood test that looks for a specific antibody. However, many people who have the antibody never get symptoms of celiac disease. The ultimate test is an intestinal biopsy.

My take-away conclusion is that all this gluten-free stuff you see in, for example, restaurants, is just the latest dietary fad. For over 99% of us there is no health benefit to avoiding gluten.

So How Much Pizza Do Teenagers Eat?

This is kind of a quirky item. If nothing else, it demonstrates how weird the medical literature can be sometimes. Every parent knows kids, teenagers in particular, mostly love pizza. A recent article in Pediatrics, a fairly respected journal, used food surveys to find how much pizza kids eat and the percentage of their daily calories they get on average from pizza.

The answer? The authors claim that in 2010 21% of kids ages 12-19 reported eating pizza sometime in the past 24 hours. That number is actually down from a similar survey in 2003. What about calories? For those kids who reported eating pizza, it accounted for about 25% of their daily calories, and that hasn’t changed. The authors primly suggest that we should make pizza more nutritious. I wish them luck with that. And I’m 63 years old and still like pizza.