1
SUBJECTIVE PERCEPTION OF HYPERSENSITIVITY TO CHOSEN
ADDITIVE-CONTAINING FOODS IN THE POPULATION OF
CHILDREN AND YOUTH
Ewa Zagórecka 1, Maciej Kaczmarski 2, Janina Piotrowska-Jastrzębska 1
Department of Propedeutics of Paediatrics, Medical Academy of Białystok
Head: Janina Piotrowska – Jastrzębska, M.D., Ph.D.
2
III Department of Paediatrics, Medical Academy of Białystok
Head: prof. Maciej Kaczmarski, M.D., Ph.D.
1
Adverse reactions to food constitute a significant problem, particularly in the population of
developmental age. According to Chandra, at least 30% of people experience symptoms that
indicate food intolerance once or more during their lifetime.
Of all adverse reactions genuine food allergies constitute approximately 20 to 30-40%. The
term is used to describe a syndrome of clinical symptoms (organic, systemic) appearing in the
human organism after the ingestion of foods or food additives and due to abnormal immune
response. More frequently, however, mechanisms other than immune are involved. The
reactions are defined as non-immune hypersensitivity (food intolerance) and can result from
harmful action of certain substances contained in food, such as toxins (poisoning) or active
pharmacological compounds (tyramine, caffeine), or may be due to enzymatic, metabolic and
other disorders.
Determination of genuine incidence of adverse reactions to foods in the population,
including food allergy, poses numerous problems. First of all, great discrepancy exists
between subjective perception of adverse symptoms by adults or parents with respect to their
children and clinical evidence of adverse reactions to foods.
In British surveys, up to 20% of adult responders believed to have symptoms of food
allergy, while blind challenge tests confirmed adverse reactions in 1.4%. Up to 28% of
parents involved in a study conducted by Bock declared that their children had at least one
event of adverse symptoms following food ingestion. However, the latest epidemiological
data indicate that the frequency of reliably evidenced allergy to e.g. cow milk protein – being
the most common in childhood – ranges between 1.8 and 4.4%.
The incidence of adverse reactions to substances purposely added to food is even more
difficult to determine.
The so called food additives constitute a numerous group of chemical compounds varying
in structure, physico-chemical features, biological and toxicological properties, origin and
functions. Their use in food production, in pharmaceutical and cosmetic industries is
determined by a number of factors. The major aim is to improve the quality of products and
their sensory attractiveness or to ensure proper productive, technological and storing
processes. Food additives admitted to use are safe for general population when used according
to legal regulations. However, adverse reactions to food additives have been described in
hypersensitive patients.
The incidence of intolerance to substances purposely added to food is difficult to
determine for a number of reasons, although according to Würthrich and other researchers it is
considerably less common than is believed. The difficulties are due to the use of different
diagnostic criteria (e.g. case history data, challenge tests), different selection and number of
2
patients, problems to identify individually harmful additives (type and dose of substances
used in challenge tests) and many others.
Pathogenetic mechanisms of adverse food reactions induced by additives have not been
fully elucidated. IgE-dependent allergies, which can be confirmed in diagnostic tests (skin
tests, allergen-specific IgE) – e.g. allergy to carmine dye, annato, aspartam or sulphites,
constitute only a small part. Cases of intolerance (non-immune mechanisms) which can be
diagnosed by means of the golden diagnostic standard i.e. double blind placebo-controlled test
(DBPCFC) hold the majority. In future, the assessment of the secretion of sulfidoleukotriens
by peripheral leukocytes isolated from patients and stimulated by food additives may be of
certain help. This type of study has been recently conducted by Worm et al. (2001).
According to the European Communites Scientific Committee for Food, adverse reactions
to additives refer to 0.03-0.15% of the adult population. In a research conducted among adults
in Denmark and England, the incidence of intolerance to food additives was found to be 0.010.23%. In the study of Young carried out on children and adults (c. 30,000 people) a total of
7.4% of responders associated different types of adverse symptoms with food additives.
Eventually, verified by DBPCFC tests, the incidence was estimated at 0.026%.
Adverse reactions to food additives are more likely to occur in the population of children
than adults. This is indicated by Danish studies performed by Fuglsang et al. on 4,952 school
children (5 - 16-year-olds) and in the group of 472 children with allergic diseases. Open
challenge tests using mixtures of various additives were positive in 9.8% and 7%, while
DBPCFC method revealed intolerance in 1% and 2% respectively. The authors emphasised
the fact that adverse reactions to additional substances were much more common in allergic
children.
In Mexican studies carried out by Madrigala et al. hypersensitivity to substances added to
food referred to 0.6% of children.
In Poland, there are no epidemiological data concerning the incidence of intolerance to
food additives among children. Therefore, the present study has been undertaken in the
Białystok centre and will be conducted in stages. The aim of the first stage – already
accomplished – was to determine the incidence of subjective perception of adverse symptoms
following ingestion of particular foods rich in additives. The subsequent stages will involve
verification of preliminary results, by e.g. open challenge and double blind placebo controlled
tests.
Questionnaire investigations conducted in autumn 2001 among parents of children and
adolescents aged 6-16 years, attending randomly selected schools in Białystok and randomly
chosen classes in these schools. The analysis included 5,044 properly and completely filled in
questionnaires (74% returnability); Chi² independence test was used for statistical
calculations, with significance levels defined as p<0.05.
The group involved in the study consisted of 2,538 girls (50.3%) and 2,506 boys (49.7%);
23% were aged 6-8 years, 35.4% - 9-11 years and 41.6% - 12-16 years.
According to parents, 14.6% (734) of children experienced different types of adverse
symptoms following food ingestion, due to food allergy or intolerance. In this subgroup,
47.4% (348) were boys and 52.6% (386) girls. The incidence of adverse reactions to foods
was statistically significantly correlated with age - symptoms of intolerance were more
common in younger age groups compared to older children – p<0.05 (approximately 17-18%
in 6-7-year-olds, 7% in 13-14-year-olds). 13% of the responding parents (664) stated that
food allergy or intolerance was diagnosed by a physician (at present or in the past), the
problem referring to 49% (320) of boys and 51% (328) of girls. Likewise, in the same group,
the incidence of reported food allergy/intolerance was correlated with age (p<0.05), but not
with sex.
As reported by parents, of 5,044 inquired children 9.3% (467) were or still are on a diet
with certain limitations or elimination of various products.
3
The analysis of the questionnaire data showed that 9,8% children (497) demonstrated
subjective adverse symptoms after ingestion of certain products containing additives. This
referred to 47.9% (238) of boys and 52.1% of girls (259) and was most frequently reported by
parents of 6-9-year-olds (13-14%) and most rarely (5%) by parents of 14-15-year-olds.
Statistical analysis showed a significant correlation with age (p<0.05), but not with sex.
According to parents, adverse symptoms associated with intolerance of food additives
were most common in children after the consumption of sparkling drinks like Coca-Cola or
orangeade – 9% (458), sweets (chewing gum, sweets, crisps, cakes) – 6.64% (335), fast food
and fruit – 4% (204}.
The most common adverse symptoms due to the consumption of foods reported by parents
as intolerated included: abdominal pain – 9.9% (503), cutaneous rash – 8.8% (446), cough
and rhinitis – 5.5% (280) and 5.6% (282), and headaches – 4.9% (248). The incidence of
symptoms from the skin (cutaneous rash, exacerbation of atopic dermatitis, urticaria), gastric
disorders (abdominal pain, loose stools), cough, rhinitis, concentration disorders and
hyperactivity was statistically significantly correlated with age – younger children reacted
more frequently (p<0.05). No correlation with age was found in the case of such symptoms as
itching of the skin, dyspnoea, headaches and systemic reactions. No statistically significant
differences were also observed in the incidence of the above symptoms in relation to sex.
In the subgroup of 497 (9.8%) patients with suspected hypersensitivity to foods rich in
additives 63.4% (315) reacted with adverse symptoms following ingestion of various types of
sparkling drinks, 48.9% (243) – sweets and 31.4% (156) - fast food. The incidence of adverse
symptoms after ingestion of various types of spices was statistically significantly correlated
with age (p<0.03) – being more common in older children. In the case of the other types of
food no correlation with age or sex was revealed.
The most common manifestations of food intolerance in this subgroup (497) included
abdominal pain 61.8% (307), cutaneous rash 55.3% (275), rhinitis 38.8% (193), cough 38.2%
(190), headaches 33.4% (166) and hyperactivity 29.2% (145). A statistically significant
correlation with age was observed in the case of such symptoms as exacerbation of atopic
dermatitis (p<0.03), cough (p<0.02), nausea/vomiting (p<0.01) – these symptoms were more
frequent in younger age groups, and headaches (p<0.01) being more common in older
children. No correlation with sex was found.
Taking into consideration adverse symptoms after consumption of food additives in atopic
or hypersensitive children, the cases well known from literature, the incidence of declared
intolerance to additive-containing foods was compared between children with and without
diagnosed food hypersensitivity (664 and 4,380, respectively). Statistically significant
differences (p<0.001) were found for each information (type of food, clinical symptoms),
with higher intolerance incidence in hypersensitive children.
At the present stage of the study – elaboration of the questionnaires – we are not able to
determine the genuine incidence of intolerance to food additives. The incidence of
subjectively perceived intolerance to foods rich in additives was estimated at 9.8% - which,
however, has to be verified.
The knowledge of the real extent of the problem of adverse reactions to food additives and
their diagnosis seems essential. It can clear the patients from suspicions and may prevent
relating different ailments to imaginary intolerance. On the other hand, confirmed diagnosis
will allow elimination of these substances, being the only suitable therapeutic management.