TABLE OF CONTENTS
1. PEANUT ALLERGIES
2. EARLIER RECOMMENDATIONS
3. LEAP STUDY
4. SUBCUTANEOUS EXPOSURE TO PEANUT PROTEIN
Food allergies are an increasing concern in many countries. One of the most life-threatening food allergies is an allergic reaction to peanuts. “The prevalence of peanut allergy among children in Western countries has doubled in the past 10 years, and peanut allergy is becoming apparent in Africa and Asia” (Toit et al 803).
With many foods being manufactured and/or packaged in facilities that also handle foods with peanuts, even foods that don't specifically contain peanuts can be contaminated with peanut dust. For some with severe allergies, even exposure to this dust contamination can result in a serious reaction. The increasing numbers of children with peanut allergies has resulted in segregation of these children in the lunchroom and even some schools going completely peanut-free, forbidding other students from bringing in to the school any peanut containing products, including the lunch staple – peanut butter and jelly sandwiches. Rather than continued restrictions as a means of safe guarding those with peanut allergies, exposure to peanuts in infancy could reduce the likelihood that children will develop peanut allergies at all.
1. PEANUT ALLERGIES
Food allergies are the leading cause of anaphylaxis treatment in emergency rooms, as noted by Sampson (1295). In the United States, there are more than 30,000 anaphylactic reactions reported each year, with more than 2,000 hospitalizations as a result. There are more than 200 deaths each year, due to food allergies, with allergies to peanuts and tree nuts accounting for the majority of these fatal, as well as near-fatal, incidents. Additionally, unlike some allergies that children may grow out of, peanut allergies demonstrated in childhood typically persist throughout the person's lifetime (Zeiger S77).
Today, approximately 1 percent of children in the United States have a peanut allergy. Anaphylaxtic reactions, including difficulty breathing and loss of consciousness, occurs when an allergic person's immune system responds abnormally to the harmless proteins in peanuts (“Peanut Allergies”). Some people are so allergic exposure to peanut dust alone can cause an allergic reaction.
According to Patel, 90% of American households consume peanuts, with approximately 32% of products being labeled with precautionary peanut allergy labeling. Common products include peanut oil, candy (especially chocolate which is often processed in the same facility as candy made with nuts), cereals, granola, pesto sauce, marzipan, some vegetarian burgers, health food bars, and many ethnic foods including Chinese, Thai, Mexican, and Vietnamese cuisines. In fact, the United States is the third largest producer of peanuts, behind China and India. The prevalence of peanut consumption, along with the severity of peanut allergy reactions, and the fact that most people remain allergic to peanuts throughout their lifetime, makes the prevention of the development of peanut allergies a serious concern.
2. EARLIER RECOMMENDATIONS
In the past, dietary restrictions on mothers who were pregnant or breastfeeding were believed to be effective in preventing the development of peanut allergies in their children. Pregnant women were recommended to exclude peanuts from their diets. Breastfeeding women were also told to eliminate peanuts, as well as tree nuts, and consider eliminating eggs, cow's milk, fish and certain other foods while breastfeeding (Patel).
Similar restrictions were encouraged for the children themselves. Solid foods were not recommended until the child was at least six months of age. Dairy products were recommended to be excluded from the diet until the child was at least one year old. Children under two years of age were recommended not to consume eggs. Lastly, for peanuts, as well as tree nuts and fish, it was recommended that children not consume these until they were at least three years old (Patel). These recommendations have not been effective in preventing the development of peanut allergies. In fact, peanut allergies in western countries have doubled in the last ten years, with now a marked presence in regions that previously had only the rare report of peanut allergies, like Asia and Africa (Toit et al 803).
3. LEAP STUDY
Researchers from King's College London created Learning Early About Peanut Allergy (LEAP). This study followed observation of the difference in prevalence of peanut allergies, in Israeli children living in Israel versus children with similar Israeli ancestry living in the United Kingdom. “The study tested the hypothesis that the very low rated of peanut allergy in Israeli children were a result of high levels of peanut consumption beginning in infancy” (NIH).
LEAP studied 640 high-risk infants, between the ages of four and eleven months. “High-risk” infants were those who had an eczema and/or egg allergy risk factor. Eczema risk factors included: a reported frequent need for treatment with topical corticosteroids or calcineurin inhibitors, parents who report the infant have severe rashes in the infant's joints or skin creases, or a clinician SCORAD grade of >40. Egg allergy risk factors included: an SPT-induced wheal diameter of 6mm or more, using raw egg whites and without a previous history of egg tolerance, an SPT-induced wheal diameter of 3mm or more from pasteurized egg white and an egg allergy reaction history (Toit et al 804).
The infants were given an initial skin-prick test and then were randomly assigned to two groups (Toit et al 804). One group was instructed to avoid peanut consumption completely. The other group was instructed to at least 6 grams of peanut protein each week. These participants continued on these regimens until they were five years old. In addition to completing dietary surveys by phone, the children were also monitored by health care professionals (NIH).
At five years of age, each child was given an oral food challenge containing peanut, while being supervised. The researchers found there was an 81 percent reduction in children with peanut allergies, for the children who had been in the group instructed to eat peanut protein, compared to the group that was told to avoid peanuts completely (NIH).