Expert Profile: Dr. Janice Joneja is a researcher, educator, author, and clinical counselor with thirty years of experience in the area of biochemical and immunological reactions involved in food allergy and intolerance. She holds a Ph.D. in medical microbiology and immunology, and is also a dietitian (RD), registered in the College of Dietitians of British Columbia. She is an adjunct professor in the Faculty of Agricultural Sciences at the University of British Columbia, and an Honorary Research Fellow in the School of Biosciences at the University of Birmingham in England. She is the author of several books including Dealing with Food Allergies: A Practical Guide to Detecting Culprit Foods and Eating a Healthy, Enjoyable Diet
and Dealing with Food Allergies in Babies and Children.
30 Years ago Janice Joneja found herself in a situation no parent wishes on another. Her son had asthma, eczema and horrible reactions to certain foods including vomiting, migraine headaches and anaphylactic shock (to peanuts).
At the time, very little was known about food allergies. In fact, after her son was hospitalized at age 13, a psychologist recommended he stay with someone else because he deemed “stress at home” the cause of his bad reactions.
Even with a PhD in immunology, Dr Joneja could not help her son get better. The more expert advice she sought out, the more that she realized that the research in this area — and help to struggling parents — was almost nonexistent. So she decided to focus her work and research on food allergies and helping families in need. This led to the development of her company, Vickerstaff Health Services Inc.
After talking with Dr. Joneja, and reading the latest research on food allergies, I found out some surprising tidbits of information. But before getting started, let’s review the basics.
Food Allergy 101
According to clinical guidelines developed by the National Institute of Allergy and Infectious Diseases (referred to as The Guidelines throughout this post), the definition of a food allergy is, “an adverse health effect arising from a specific immune response that occurs reproducibly on exposure to a given food.”
Food allergies always involve an “immune response.” The allergen-specific immune cells mistakenly see the food component (typically protein) as a threat to the body and then they react. Symptoms can include vomiting, diarrhea, skin rash/lesions, itching, swelling, difficulty breathing, blood in stool and worsening of asthma and eczema .
“The problem is not with food as people think, it’s the body’s response to different food components that causes problems,” says Joneja. “After food is eaten it goes through a complex system of digestion and specific immune responses.”
According to the Food Allergy and Anaphylis Network, 8 foods account for 90 percent of all food allergies. These items, called food allergens, include wheat, milk, egg, peanut, tree nuts, fish, shellfish and soy. Although studies show food allergies are over-reported, scientists believe they have increased over the last 10 to 20 years.
Some kids are at higher risk for developing food allergies including those with a parent or sibling with asthma, allergic rhinitis, atopic dermatitis or food allergy. According to the CDC, children with food allergies are two to four times more likely to have conditions like asthma, atopic dermatitis and respiratory infections.
So with this in mind, let’s get to the information every parent must know about.
1) Delaying the introduction of food allergens is unnecessary: According to The Guidelines and a report by the American Academy of Pediatrics, there is little evidence that delaying the introduction of solids past 6 months, and waiting to introduce potentially allergenic foods, prevents food allergies.
“Parents who wait to introduce food allergens to their kids may miss a window of opportunity,” says Joneja. “If young children don’t get exposed to low dose food allergens their GI system can mature to the point where their body may not tolerate it.”
Joneja explains how health professionals used to recommend young children avoid food allergens until they were older. Now the opposite is believed to be true.
Being the neurotic parent I am, I asked her about life-threatening reactions to foods like peanuts. My thought was it might be better to wait until a child is older so they could communicate with you. Joneja said that this anaphylactic complication not only is rare (<.2%), but is more likely to happen in late adolescence and adulthood.
As far as prevention, there is strong evidence that exclusive breastfeeding for at least 4 months helps prevent atopic disease and some evidence that hydrolyzed infant formulas reduce allergy to cow’s milk for at-risk infants. Joneja says that only women with known food allergies need to exclude food allergens from their diet.
2) Not all reactions to food are food allergies: When someone has a reaction to food it is not always a food allergy — it can also be a food intolerance. As said earlier, food allergies involve an immune response. Food intolerances do not and their cause is either metabolic, pharmacologic or undefined.
One example is milk allergy vs. lactose intolerance. A milk allergy is an immune response to milk protein where lactose intolerance is the inability to digest lactose in milk.
Other intolerances that adversely affect behavior may be caused by food additives such as artificial colors and certain preservatives. Many parents still think sugar sends their children climbing the walls but research shows it’s more likely to the additives in the food (more on this fascinating subject in an upcoming post).
According to a recent study published in the Journal of the American Medical Association, 30 percent of people believe they have food allergies when only 5 percent of children and 8 percent of adults do.
3) Most kids will outgrow food allergies:“90 percent of children out grow food allergies by the age of 7” says Joneja. “Sometimes parents will see tolerance of food allergens as early as two years of age”
Joneja explains how developing a food allergy as a young child is the best case scenario. That’s because food allergies in children are much more likely to be out grown than those that begin later in life.
According to The Guidelines, children with allergies to milk, egg, wheat and soy generally resolve while allergies to peanuts and tree nuts are more likely to persist. So if your child has a food allergy, make sure to talk to your pediatrician about when and how to re-introduce allergenic foods.
4) Blood or skin prick tests alone cannot diagnose a food allergy: Joneja says that IgE antibody blood tests and skin prick tests are only 50 percent accurate and can result in false positives or negatives. She believes skin prick tests to be the least accurate and problematic — and does not recommend them.
Instead of relying on single tests, The Guidelines recommend a variety of tests for food allergies including medical history, blood tests, food elimination diets and oral food challenges. Talk to your pediatrician or allergist about the combination of tests best for your child.
5) Older children can still develop food allergies: Once a child has tried most foods, parents may sigh a big relief that their child is food-allergy free. But in some cases, food allergies can appear in adolescence and even adulthood.
Milk, eggs and peanuts account for the vast majority of allergic reactions in young children while peanuts, tree nuts and seafood are more common with teenagers and adults. Sometimes in older kids the allergic reaction only occurs with exercise, alcohol consumption and non-steroidal anti-inflammatory use.
Allergic reactions to food or food additives can be immediate or delayed. Immediate reactions occur within minutes to a few hours while delayed symptoms may take several hours to a few days. This is it’s important to wait a few days after introducing a new food to babies and toddlers.
There are still many myths about the development of food allergies in kids and adults — and the science will continue to evolve. Restricting young kids’ diets or delaying the introduction of solids unnecessarily can cause nutrition deficits. So if your child is at higher risk for developing food allergies, or is experiencing signs and symptoms, make sure you see an experienced food allergist.
Anything written here surprise you? Would love to hear about it in the comments.
Chafen JJ, Newberry SJ, Riedl MA, Bravata DM, Maglione M, Suttorp MJ, Sundaram V, Paige NM, Towfigh A, Hulley BJ, Shekelle PG.
Diagnosing and managing common food allergies: a systematic review. JAMA. 2010;303(18):1848-1856.