CLINICAL NUTRITION

CERTAIN FOODS PROVOKE MIGRAINE

An open study suggested a good response in migraine sufferers to antigen avoidance diet. Specific foodstuffs were found to provoke attacks in two thirds of patients

subsequently in a double blind crossover trial.

Key Words: migraine, diet, oligoantigenic diet

Migraine is a puzzling clinical phenomenon with a wide range of signs and symptoms, and is common in both pediatric and adult practice. A large placebo response is often found after initiating treatment of any sort,’ making control trials difficult to establish. Many cases appear refractory to all drug therapy and a group of workers have now investigated previous sug- gestions that the disorder is largely a complex form of food allergy.2

Ninety-nine children, clinically diagnosed as having migraine, with a history of headaches at least weekly for the previous 6 months, entered the first stage of this trial. Existing drug therapy was maintained, but their diet was altered to a nutritionally complete oligoantigenic diet. The latter consisted of one meat, one carbohydrate, one vegetable, one fruit, water, and vitamin and mineral supplements. If patients devel- oped symptoms on this diet, another oligoanti- genic diet was started. This was maintained for 3 or 4 weeks. If symptoms were absent for 2 weeks, excluded foods were separately intro- duced at weekly intervals. Foods provoking symptoms were withdrawn and the above was continued until a socially acceptable diet was attained. Patients who had responded to foods available for testing were then invited to partici- pate in the second part of the study, which was designed as a double blind crossover trial. Tins of individual foods were prepared to a sweet or savory base; the “active” tins had the suspect- ed provoking food added as a powder. Forty patients participated in this part of the trial, and were placed for a one week period on either the “active” tins or those containing placebo alone.

Following a washout period, the corresponding preparation was used. These preparations were reportedly indistinguishable in both color, taste and texture. Symptoms were recorded by the parents during both periods. In addition, skin tests to 28 antigens were performed in all patients and total IgE and IgE antibodies to 16 of the same antigens measured.

Out of the 99 patients commencing the trial, 88 completed the oligoantigenic phase. Seven- ty-eight of these recovered completely and 4 showed improvement. Only 8 of these did not relapse after introduction of foods and these have remained well. Forty of the remaining 74 patients entered the double blind controlled tri- al. Foods were added according to the views of the patient and family, so not every child was tested with every food. Eight of the children had no symptoms with any of the foods and 17 with only one. Most, however, reacted to several foods. The most common provoking foodstuffs were cow’s milk, eggs, chocolate, orange and wheat. Symptoms were provoked any time be- tween 1 hour and over 7 days after starting the particular food, with a median time of 2 days. Symptoms took an average of 2 to 3 days to disappear, with a range of under 1 day to 3 weeks. Neither the skin tests nor the IgE anti- bodies were useful in predicting causative foods. Seven patients were later found to be asymptomatic when causative foods were in- troduced and 4 of these are now on a normal diet.

Any trial performed on migraine sufferers is fraught with difficulties, owing to the high spon- taneous cure rate and the effective response often seen with placebo. This makes interpre- tation of the pilot trial very difficult in this study,

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particularly as the therapy of an oligoantigenic diet is a particularly severe one, both for the patients and their families. It is also of note that all the children suffering from migraine included in this study were fairly severely affected (not the type most commonly seen in pediatric prac- tice) and also that drug therapy was continued in all cases. Even so, the “cure” rate of 93 per- cent seems very convincing. This appears to be confirmed by double blind crossover trial, in which just under 50 percent of the original co- hort of patients participated. Eight patients were asymptomatic on both active food and placebo; but 26 reacted with migrainous symp- toms when fed active food compared to only 2 on placebo (p<O.OOl). Later follow up has dis- played a spontaneous cure rate starting 70 oc- cur in the former group. The absence of IgE antibodies to many of the foods suggests an- other mechanism of causation and the authors postulate that this may be due to released me- diators from the gut on circulating antigen or antibody:antigen complexes. This may, in part, explain the length of time seen in many of the patients between ingestion of the provoking food and commencement of the migrainous symptoms.

In summary, a high proportion of severe childhood migraine sufferers were relieved of their symptoms by an oligoantigenic diet in a double blind crossover study. It appears that dietary provoking factors were proved in just under two-thirds. The authors correctly point out that oligoantigenic diets are potentially harmful and should only be used under expert supervision. The difficulty of instituting such diets and maintaining them under domestic conditions means that such treatment of mi- graine will of necessity only be applicable to a small minority of migraine sufferers who are highly motivated and have not responded to drug therapy. The process can only be facilitat- ed by a laboratory investigation which will iden- tify the provoking antigen. 0

1. P.J. Congdon and W.I. Forsythe: Migraine in Childhood: A Study of 300 Children. Dev. Med. Child Neurol. 21 : 209-216, 1979

2. J. Egger, C.M. Carter, J. Wilson, M.W. Turner and J.F. Soothill: Is Migraine Food Allergy? Lan- cet 2: 865-869, 1983

NUTRITION INTERVENTION IN PREGNANCY

In The Gambia, prenatal dietary supplementation improved birthweights and substantially reduced the incidence of low birthweight in the wet season, but not in the dry season.

Key Words: birthweight, pregnancy, food supple- mentation, The Gambia, low birthweight

Low birthweight is caused by factors which im- pair fetal growth and/or shorten the length of gestation. Some of the factors associated with low birthweight, such as multiple pregnancies or high-altitude residence, are non-interven- able. Some factors, including low socioeco- nomic status, can only be influenced by long- term interventions. Most appealing from the public health viewpoint are interventions which are short-term and cost-effective. Dietary sup-

plementation during pregnancy would seem an ideal intervention since an inadequate mater- nal food intake is known to affect birthweight adversely and birthweight is an important de- terminant of infant health and survival. Thus, a major focus of many maternal and child health programs is the provision of additional food to pregnant women whose dietary intakes are limited by poverty or food shortage. Unfortu- nately, few such interventions have ever been evaluated. One exception is the United States Department of Agriculture’s special supple- mental food program for low-income women,

42 NUTRITION REVIEWSNOL. 42, NO. WFEBRUARY 1984