The American diet has been a topic of discussion in the media, and multiple diets have been proposed as the solution for a wide range of health problems, both physical and psychological. Food allergy is often blamed for reactions ranging from classical allergic reactions to hyperactivity in children. For the lay public, this information can be very confusing and misleading. So what is the truth?
There is no debate that diet and the foods we eat are a major cause of obesity, cardiovascular disease, diabetes, and a slew of other health issues. Also, there is no question that limiting the sugar and junk that children eat would be a good thing. When it comes to foods and allergy, the picture becomes more clouded. There is no question that foods can cause allergic disease as manifested by hives, asthma exacerbations, eczema, and life threatening attacks. True food allergy has a prevalence of approximately 6% in the pediatric age group and about 1% in the adult population. These reactions are usually caused by a few foods (e.g. peanut, tree nuts, fish, shellfish, milk, and egg), but any food can be the cause of a reaction in an individual. These reactions are typically mild skin breakouts and upset stomach, but in rare situations can become explosive allergic reactions. These are usually clear cut based on a history of ingesting the suspect food and the immediate reactions which occur. These can be diagnosed with a positive skin test or RAST blood test which measure allergic antibodies to the food in the patient’s system.
What about the other reactions?
It has become popular in the lay press to blame foods for a spectrum of behavioral diseases, especially hyperactivity in children. The truth is that there is very limited scientific data to confirm this association. There are a few studies which show that sugar and food dyes (FD&C dyes) can be an issue in a very small percentage of ADHD children. The dilemma for the physician is that we don’t have a good test to confirm this association. Skin testing, although helpful, can be falsely positive in 50% of patients. This means that a patient with a positive skin or RAST test to a food will only have a problem half the time. Along with this finding, we know that it is exceedingly rare for an individual patient to be truly allergic to more than three foods so one should question your physician if they tell you to avoid a grocery list of foods based on skin testing or RAST alone. Some authors propose the measurement of IgG levels to foods as a marker for those susceptible to behavioral changes. There is no scientific data at present that these levels correlate with disease. The best way to determine whether a food is causing a reaction is with a double blinded challenge where neither the child nor the observer knows what the child is ingesting. This can be done in coordination with your allergist, pediatrician, or dietician. It is imperative that you coordinate this with one of the above professionals if several foods are to be eliminated as this is a pivotal period in a child’s growth, and nutritional deficiencies can occur if too many foods are avoided simultaneously
So what is a parent who is looking for help supposed to do?
First, before launching into an exhaustive dietary change, seek the advice of an expert in ADHD to make certain of the correct diagnosis for your child. Second, if someone gives you an easy solution, such as removal of a single food from the diet, you can probably assume that this is “too good to be true.” My suggestion would be to eliminate suspicious foods from the diet for a period of 3-4 weeks and then reintroduce them one at a time. If behavioral changes occur, then there may be something to the association. As discussed above, sometimes this has to be done in a blinded fashion in order to confirm the relation in an unbiased fashion. I will usually recommend that the father or mother fix the food and not tell the other what they are feeding the child. The school can also be a resource as the teachers are with the child a significant part of the day and can give a report on the child’s behavior; however, they must be kept unaware of what the parent is doing as they can be biased. I suggest the teacher be asked to give a report on your child’s behavior over a several week period without letting them know that the diet has been changed. Remember, if you determine that multiple foods are causing your child trouble you need to discuss this with a medical professional to make certain you are not harming your child nutritionally.
Finally, behavioral disorders in children can be very stressful for the parents so make certain that you seek help for your child and yourself. As I tell my patients and parents, alternative therapies can occasionally be helpful in addition to standard medical care, but these must be used in coordination with a medical professional’s help as you may do more harm then good. Be wary of the person that tells you that their therapy is the cure-all and that your M.D. just hasn’t learned about this great therapy as of yet. As my barber once said,” if they found a cure for hair loss, they wouldn’t have to advertise!” If a therapy works that well, I want my patients to have access to it!
Written by Allergy Care physician, Mark Corbett, M.D.