Specific nutritional factors such as folate excess and Vitamin D deficiency may shed some light on why food allergies are more common now than they were 20 years ago, Dr. Robert A. Wood, the chief pediatric allergist at Johns Hopkins Children’s Center, told a food allergy group May 18, 2013.
“There are lots of theories out there, and there are at least 10 theories that have some evidence to support them,” Dr. Robert Wood said during a session on food allergies and anaphylaxis management at the Food Allergy Research & Education (FARE) 20th annual allergy conference in Arlington, Va.
However, the internationally recognized food allergy expert told the group, they still “really don’t know” why food allergy is more prevalent now.
Moreover, with regard to whether there is evidence that food allergy can be prevented, Dr. Wood said, “I’m going to give you some very encouraging information about the treatment of food allergy, and I’m going to give you no encouraging information about the prevention of food allergy.”
After receiving a response of nervous laughter from the audience, he continued: “That’s because to understand prevention, we have to understand the reasons we’re seeing this higher rate, and we don’t understand it well enough yet.”
For parents like me who have a child with food allergies, prevention and nutrition are important topics, especially when preparing for a second child. Throughout his presentation, Dr. Wood addressed these concerns and more. (See related story on how to recognize severe allergic reactions.)
Several Contributors Seen as Likely.
Dr. Wood said there are likely several reasons why food allergy is more common now, and there probably are other theories we haven’t yet thought of or even understand.
For example, he said, there is the hygiene theory: That our environment today is too clean and that not being exposed to normal, benign germs and bacteria early in life may leave our immune system less busy, thereby allowing it to focus on other things like allergens.
Dr. Wood also addressed questions about diet, and whether the way we process foods and use pesticides in foods may be promoting food allergy. In response, he said, “There is very little evidence that food processing has made a big difference in food allergy.”
“I think in the end it will turn out there are 5 or 10 or 15 different things that have happened in our lives and our environment, [such as] the use of medicines, immunizations, that led to the increase in food allergy,” he explained.
“It will not be a simple explanation,” Dr. Robert A. Wood told the group.
There is evidence that other nutritional factors, such as having too little Vitamin D and having too much folate, may promote food allergy, he said.
In particular, having too much folate “is much more common than it was 20 years ago, because we started supplementing pregnant women with folate,” he said.
In a similar vein, Vitamin D deficiency “is now much more common than it was 20 years ago, because we stay indoors and we wear sunscreen,” he said.
“What has to make sense with many of these theories is: What has happened in our lives, our diet, or our environment in the last 20 years? Because the rise in food allergy really happened over the last 15 to 25 years.”
Dr. Wood went on to say the rise in food allergy is not due to genetics. “Our gene pool did not change in the last 20 years,” he explained.
Food Allergy ‘Rising Sharply’ in All Countries.
While Dr. Wood said there is no simple explanation for why food allergies are on the rise, he did say the prevalence of food allergies is “very similar and equally increasing” in all countries around the world. In particular, milk allergy is the most common, affecting 2.5 percent of children around the world, he said.
He went on to say that at least 12 million Americans are affected by food allergy. Also, more children are carrying their allergies into adulthood, according to Dr. Wood.
Moreover, he said, “Peak prevalence usually occurs at one year of age.”
Food Allergy Research & Education (FARE) is a nonprofit organization that provides advocacy and education on behalf of individuals with food allergies. This article is my first in a series of special reports on FARE’s 2013 annual conference. Check out FARE’s website at http://www.foodallergy.org/ for more information.
Do you have advice about successfully introducing foods to a high-risk child? Did you take any special steps that you feel prevented allergies in your children? I’m working on a related story about prevention theories and would love to hear about your experience.
Image by photographer pogonici/www.shutterstock.com.