Dear Dietician: Scientists study roots of food allergies
Food allergies are on the rise in the United States, and it is estimated that as many as 8 percent of children suffer from at least one food allergy. A food allergy occurs when your body’s immune system responds to a particular food as harmful and has a reaction. These reactions can range from itchy skin, vomiting, diarrhea, trouble breathing, wheezing, or life-threatening anaphylaxis.
Although it is uncertain why food allergies have increased, one theory is the hygiene hypothesis. Our immune system’s job is to fight germs and stave off infections. However, our homes have been sanitized with bleach and antibacterial soap. In our efforts to provide clean homes for our families, our immune systems may have encountered an identity crisis, so they are looking for a new job. In this scenario, the body responds to a particular food as harmful and takes measures to protect itself.
Another contributor to food allergies may be food processing. For instance, China’s peanut allergies are far less common than in the United States. While peanuts are roasted in the United States, they are boiled in China. Boiling does not alter the protein in peanuts as does roasting, and typically, it is the protein in foods that acts as the allergen.
There are eight foods that account for 90 percent of all food allergies. They are:
- Cow’s milk
- Tree Nuts
Peanuts, milk, and eggs are the most common food allergies in children. While many children outgrow these allergies, some will have them their entire lives.
In the past, physicians have advised parents not to introduce potential allergic foods to children until age 3. However, recent studies have shown that introducing these foods earlier in infancy may help prevent allergies from developing. The LEAP study (Learning Early About Peanuts) was the first randomized trial to study early allergen introduction as a preventive strategy. It found that the introduction of infant-safe peanut-containing foods at 4–11 months of age significantly reduced the risk of developing peanut allergy in high-risk infants (1).
High-risk infants were defined as those who had severe eczema or an egg allergy, or both. The LEAP study results were published in the New England Journal of Medicine.
Similar studies have been conducted on the early introduction of eggs to prevent allergies, but the results have been mixed or inconclusive. More research needs to be performed on food allergies to provide safe recommendations.
If you are concerned about food allergies for your child, talk to your pediatrician. Refrain from providing any of the foods mentioned above to your child until approved by your doctor.
Until next time, be healthy!
1. Du Toit G, Roberts G, Sayre PH, Bahnson HT, Radulovic S, Santos AF, et al. Randomized Trial of Peanut Consumption in Infants at Risk for Peanut Allergy. N Engl J Med 2015; 372(9):803-813. 02/26;2015/08.
Leanne McCrate, RD, LD, CNSC, aka Dear Dietitian, is an award-winning dietitian based in Missouri. Her mission is to educate consumers on sound, evidence-based nutrition. Do you have a nutrition question? Email her at email@example.com. Dear Dietitian does not endorse any products, health programs, or diet plans.