Organic Diet Intervention in Primary School Children
Condition: Oxidative Stress; Inflammation
MeSH terms: Inflammation
Study type: Interventional

Summary: 
      The study aims to evaluate the hypothesized benefits of a systematic organic diet for
      children, over those of a conventional diet. The specific objectives of this study are to: i)
      Demonstrate the decreased body burden of pesticides for those children consuming an organic
      diet, and ii) Evaluate the effects in specific biomarkers of inflammation and oxidative
      stress in children systematically consuming an organic diet.
    

Detailed description: 
      A single-blinded, randomised 2 x 2 cross-over study is conducted to evaluate the effect of a
      40-day organic diet compared to a 40-day conventional diet on biomarkers of exposure
      (pesticides metabolites) and biomarkers of effect (oxidative stress/inflammation markers) in
      children. The study is approved by the Cyprus National Bioethics Committee (ΕΕΒΚ/ΕΠ/2016/25)
      and the Cyprus Ministry of Education and Culture (7.15.06.15/2). Written informed consent for
      children to participate in the study is obtained from children's parents or legal guardians.
      Study participants are recruited from public primary schools in Limassol, Cyprus following
      communication with the school's headmaster. Each school that participates in the study is
      randomized to one of the two study arms; conventional-organic or organic-conventional.
      Participants' blinding is not possible since children know which diet they have at each
      phase. However, all documents and urine containers are coded, so that researchers are blinded
      to subjects' identity and group allocation.

      Participants provide 6 first morning urine samples during the duration of the study; 1
      baseline sample, 2 samples in the conventional phase and 3 samples in the organic phase.
      Anthropometric measurements (weight, height, waist circumference) are taken at the beginning
      and end of the study by trained researchers at the school area. A baseline questionnaire is
      administered to parents at the beginning of the study through a telephone interview to
      collect information on demographic characteristics, pesticide use at household and children's
      activities. A food frequency questionnaire is administered to parents at the end of the
      conventional phase through a telephone interview to collect information about the food habits
      of the children during the 40-day conventional period. A food diary is given to parents at
      the beginning of the study and parents use it during the organic phase, to collect
      information about the compliance of the children to the organic dietary menu, the children's
      health status and the pesticide use at home.

      In order to encourage adherence to the organic diet menu, an event is organised during the
      organic phase of both groups, with activities for children and free sampling of organic food
      products.

      Descriptive statistics are used to summarize the demographic characteristics for
      participating children. Categorical variables are described as sample size and percentages,
      normally-distributed continuous variables as mean±SD and non-normal continuous variables as
      median and interquartile range (Q1-Q3) or the appropriate transformation is conducted, such
      as the log transformation. For testing whether characteristics of interest are different
      among groups the Student's t-test are utilized for continuous normally distributed variables
      and the chi-square test for categorical characteristics. For continuous data that are not
      normally distributed, the Wilcoxon non-parametric analysis is used instead or a
      transformation of the data is conducted first in order to meet the normality criterion.

      Linear mixed-effects models are used to account for the correlation among repeat urine
      samples collected from the same child and determine whether mean pesticide metabolite and
      biomarkers concentrations differ between the organic phase and the conventional phase.
    

Intervention name(s): Organic diet
Intervention type(s): Dietary Supplement
Intervention description(s): Full organic diet from certified organic products as obtained from certified producers and cooked by a certified organic restaurant. five meals each day delivered to students.
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Single (Investigator)
Primary purpose: Other
Keywords: organic diet; health; pesticides; inflammation biomarkers; oxidative stress biomarkers