Dr. Feingold was in a unique position to recognize the dietary component of behavioral disorders:
- As an allergist, he was familiar with the long-established use of the elimination diet for determining allergenic sources - and in the case of food dyes to recognize that this was an immunological response, not an allergic reaction.
- As an allergist, he had already been using the elimination diet developed by Dr. Lockey at the Mayo Clinic for control of hidden allergens across a wide range of foods or food additives - a diet developed for skin allergy such as urticaria (hives) and aspirin-induced asthma, for both children and adults.
- As a pediatrician since the 1920's, he was aware of the historic change in prevalence of disease and behavioral problems in children during the early 1960s (when food dyes, flavorings, and preservatives proliferated on the supermarket shelves).
As Chief of Allergy at Kaiser Permanente, he had the power to have colleagues search for specific types of patients to observe, and to implement clinical studies.
With his world-wide scientific contacts, he was in a position to know what advances had been made in other countries, especially new researches on the cross-reactivity of additives and salicylates.
Having already published peer reviewed scientific papers on personality changes related to the allergic response, and on the way flea venom works [as haptens, which the low-molecular-weight food dyes do, too] - he had the background to put two and two together.
As a clinician with empathy, he actually listened to his patients even when their reactions did not match any existing textbook descriptions or treatments.
Dr. Feingold's clinical findings, often called his "hypothesis:"
Hyperactivity can be triggered by
synthetic additives - specifically
synthetic colors, synthetic flavors and the preservatives
BHA, BHT (and later TBHQ) - and also a group of foods containing a natural salicylate radical. This is an immunological - not an allergic - response.
Dr. Feingold's favorite saying:
"Any compound, natural or synthetic, can induce an adverse reaction if the individual has the appropriate genetic profile, i.e., disposition."
Other memorable statements by Dr. Feingold:
"The absence of persistent neurological deficits in the younger child, following control [by diet] of behaviour, and the greater incidence of persistent neurological deficits as the child grows older suggests that the offending chemicals operate slowly over a period of years to induce neurological damage. The degree of damage will vary from child to child, depending upon the genetic profile of the individual, and inherent toxicity of the compound, and the dosage."
"It must be recognized that except for terminology both categories of compounds, medications and food additives, are identical. They are both low molecular weight compounds. In spite of this identity not one of the thousands of compounds introduced into our food supply as additives has ever been subjected to pharmacological studies as required of compounds licensed for use as drugs."
"If a practitioner rejects dietary intervention for hyperkinesis [early name for ADHD] on the
basis of a non-specific effect, he/she must in good conscience abandon a large part of the practice of clinical medicine which is empirical."
"We have now managed approximately 600 children with the diet. Initially, our successes for control of observed behavior ranged between 30 and 50 percent; however, since we are emphasizing the elimination of BHT (butylated hydroxytoluene) and BHA (butylated hyroxyanisole), our successes for control of behavior average between 60 to 70 percent of our samples."
"Children with a history suggesting a possible cause for neurologic damage may experience a complete recovery on the diet, while others with a completely negative history may fail to respond, or may show a partial response, such as improved behavior with deficits in coordination, or cognition, or perception. The history cannot always be precise in disclosing neurotoxic factors. . . . In addition, consideration must be given to less overt factors, such as environmental pollutants of air, soil, and water, which serve as neurobehavioral toxicants during gestation or early childhood."
At any age the response is impaired in the presence of true neurological damage.
. . .
Failure to respond to strict implementation of the diet is an indication to look beyond the diet. Depending upon the biological profile, anything in existence, either natural or synthetic, may be a provoking agent.