THE ROLE OF DIET IN ADVERSE SYMPTOMS IS COMPLEX

IX. THE ROLE OF DIET IN ADVERSE SYMPTOMS IS COMPLEX

The suspect diet substances being investigated have broadened, as have the symptoms affected by diet. Both the dose of suspect substances and the age of child are relevant. There is individual variation in problem profiles presented, in symptoms that change, in amount of change, and in substances not tolerated. A review of the research from 1985 to 1995 shows that a role of diet in some ADHD children has been demonstrated (59). However, there is much work still to be done. Various mechanisms have been proposed, notably allergy and idiosyncrasy coexisting (60), neuropharmacological abnormality (65), and many others (68–76). A valuable pharmacological view is provided by Neims (77). The health of the gut may be important. Tolerance is often decreased as grain fiber is increased. New work on probiotics in the form of degradation of some protein components and adsorption of suspect chemicals from intestinal contents should be considered (78).

Note that most foods not tolerated are highly flavored: spices, teas, tangy fruit, to- mato, chocolate, aged food, foods high in monosodium glutamate, and commercial sweets and drinks. This author suggests a change in emphasis from artificial colors and preserva- tives toward flavor to the extent that all strong aromatic natural and additive flavors be equally emphasised suspect chemicals. Higher tolerance is related to mild, good quality flavor. High quality foods (e.g., fine wines) and preferred smells (e.g., expensive perfumes) are better tolerated. At the other end of the spectrum is decreased tolerance as the food is perceived as smelling stale or musty. Perhaps this is susceptibility to very small doses of spoilage organisms or their products. Clinically, food-sensitive people are more aware than others of both smell and taste. They are people whose threshold for adverse reactions seems lower than the general population, with more noticeable interaction with ‘‘the total body load’’ of factors in the environment. On a positive note, it is of interest that few food-sensitive people develop coronary heart disease, diabetes, or obesity.

A second suggestion is to no longer presume that salicylate is the main suspect natural chemical. Tolerance to salicylate-containing foods varies with individuals and does not correlate closely with analysis data. Researchers using similar methodology to Swain report finding little salicylate in their analysis of similar foods (79,80). This does not mean sensitivity to natural chemicals is not significant. Indeed, most of the later research implicates natural foods as well as additives. At this time it appears wisest to clarify the foods that are consistently causing reactions (outlined in Appendix B) and to admit that it is not known exactly what the suspect chemicals are or why they cause reactions.

In conclusion, the research, particularly from the 1980s and 1990s, has shown diet has a role. There are three groups of suspect substances: additives, natural chemicals, and whole foods, with those implicated in the family given special emphasis (81). This discus- sion has considered suspect natural substances at some length as their role is only gradually being clarified. Artificial additive color and flavor are still the most often reported suspect In conclusion, the research, particularly from the 1980s and 1990s, has shown diet has a role. There are three groups of suspect substances: additives, natural chemicals, and whole foods, with those implicated in the family given special emphasis (81). This discus- sion has considered suspect natural substances at some length as their role is only gradually being clarified. Artificial additive color and flavor are still the most often reported suspect

Further research should incorporate all of the issues raised here and should be multi- disciplinary, preferably including psychiatry, pediatrics, allergy, food technology, neurol- ogy, education, immunology, psychology, dietetics, molecular biology, toxicology, and pharmacology. The latter inclusions should have a higher profile than in early work.

The picture of what could be called the side effects of foods is complex. Food sensitivity exists and provides a challenge for all those working in related fields.