Development of double blind gluten and casein free test foods for use in an autism dietary trial
Authors: Adams S.J. , Burton N. , Cutress A. , Adamson A.J. , McColl E. , O’Hare A. , Baird G. , Le Couteur A. 
Published: July 2008

Background:  Autism is a severe long‐term neurodevelopmental disorder. Families are increasingly undertaking a gluten and casein free (GFCF) diet in response to largely anecdotal reports of autistic clinical improvement. Exclusion of staple foods can place these children, with self‐imposed limited diets, at nutritional risk (Keen, 2007). There is an urgent need to investigate the efficacy of GFCF diets in an adequately powered, medium term, randomised controlled trial (Millward et al., 2007). However, double blinding to the removal of gluten and/or casein is desirable but complex to accomplish. Therefore, this study was essential preparation for a large scale study and investigated the feasibility of producing test foods to achieve double‐blinding which are transportable, easy to prepare, palatable and suitable for daily consumption by young children with autism.

Methods:  Heron Foods Cork, developed a range of test foods including a muffin, porridge and batter mix, lemon and almond cookies and chocolate krispie bars. The estimated average habitual intake (Gregory et al., 1995) of gluten (10 g) and/or casein (10 g) was added as outlined below:

Test Food with gluten and casein added; Test Food with added casein only;

Test Food with added gluten only; Test Food with no gluten or casein added.

Groups were randomly labelled A–D. The foods’ GFCF status or presence of additions was confirmed by independent assay. R&D and ethical approval was given for health professionals to recruit 60 children with autism (3–6 years) in Newcastle, Edinburgh and London and to randomly allocate to the above groups. Following assessment of eligibility and informed consent, families received a supply of test foods, detailed cooking instructions and behaviour and food preference questionnaires for self‐completion. Parents offered test foods for 28 days and recorded daily consumption. As this study investigated the acceptability of the test foods and not the effect of GFCF diet on autism, gluten and casein containing foods were not withdrawn from the child's diet. Telephone dietetic support was available throughout. Outcomes were measured by food consumption diaries, a test foods acceptability questionnaire and telephone interviews with a sub‐set of parents. Parents and all researchers were blind to group allocation.

Results:  A total of 52 children were recruited with only three families withdrawing during the 28 days due to food refusal. Results are available for the first 43 children [A – 9, B – 10, C – 13, D – 11]. Of 38 parents responding 63% stated that their children were ‘usually willing to try new foods’ [A – 86%, B – 67%, C – 42%, D – 70%]. Ninety‐five percent of the children (n = 40) [A – 89%, B – 90%, C – 100%, D – 100%] tried at least some foods over the 28 days. Muffins and chocolate krispies were most readily accepted. Porridge and batter mix were least well liked. Children in groups A and D were most likely to consume more of the foods offered. The status of the groups is not yet known but these results suggest that porridge could be removed as an option. At interview parents confirmed these findings and suggested an alternative savoury food item such as bread should be available.

Discussion:  Families demonstrated a high level of motivation and commitment to this study indicating their desire for dietary research in autism. The research team encountering considerable challenges in both the planning and execution of this study, but despite this, a range of test foods have been produced suitable for young children with autism.

Conclusion:  This is the first study to develop and test a range of double‐blind test foods for regular consumption by young children with autism. This is essential preparation for a large scale multicentered RCT of gluten and casein free diets in the management of autism.

Funded by Research Autism & The Children's Foundation. This work was supported by the BDA General Education Trust.

References  Gregory, J.R., Collins, D.L., Davies, P.S.W., Hughes, J.M. & Clarke, P.C. (1995) National Diet and Nutrition Survey: children aged 1 1/2 to 4 1/2 years, volume 1: Report of the Diet and Nutrition. London: HMSO.

Keen, D.V. (2007) Childhood autism, feeding problems and failure to thrive in early infancy. Seven case studies. Eur. Child. Adolesc. Psychiatry. Published online Sept 14th 2007.

Millward, C., Ferriter, M., Calver, S., & Connell‐Jones, G. (2007) Gluten‐ and casein‐free diets for autistic spectrum disorder. Cochrane Database Syst. Rev.4, CD003498.