Oxidative StressORGANIKONCT02998203
Organic Diet Intervention in Primary School Children
A study testing Organic diet in people with Oxidative Stress and Inflammation, run by Cyprus University of Technology.
Trial 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… Read more about this study
- Who is it for?
- Ages 10 to 12 yearsHealthy volunteers can take part
- Conditions the study is for
- Oxidative Stress, Inflammation
- What is being tested?
- Organic diet
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 191 participants
- Where
- No sites listed yet
- Study dates
- 3 Jan 2017to 18 Apr 2017
- Phase
- Interventional
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 10 to 12 years
- All sexes
- Healthy volunteers accepted
- Child
Who may be able to join
- Healthy children aged 10-12 years, residing in Cyprus over the last five years who consume primarily (> 80%) conventional food (non-organic).
Who cannot join
- Children with chronic conditions (e.g. diabetes, asthma) or allergies in food (e.g. gluten, lactose tolerance)
About this study
Official title: Organic Diet and Children's Health - ORGANIKO LIFE+
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.
Read the 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.
- Conditions
- Oxidative Stress, Inflammation
- Being tested
- Organic diet
- Keywords
- organic diet, health, pesticides, inflammation biomarkers, oxidative stress biomarkers
- Medical subject headings
- Inflammation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Organic dietDietary supplement
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.
| Study group | Role | What they receive |
|---|---|---|
| Conventional phase | No intervention | During the conventional phase, participants are asked to maintain their usual dietary choices for 40 days. |
| Organic phase | Experimental | During the organic phase, participants are asked to follow strictly the two 20-day organic dietary menus provided to them for 40 days. The organic dietary menus were prepared by a certified dietitian. The meals of the organic phase are prepared by a certified organic restaurant and are delivered to school every day except Sunday. For the meals of breakfast and afternoon snacks, children choose their preferred options for the week on the Friday of the previous week according to a list of organic food items and the products for these meals are delivered on Saturday along with the rest meals. Parents are responsible to pick-up the organic meals from school and ensure that the participating children have access to them. Receives: Dietary Supplement: Organic diet |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Pesticide Metabolite 3-phenoxybenzoic Acid (3-PBA) Levels in Urine Between Organic and Conventional Periods*
Percent change in pesticide metabolite 3-phenoxybenzoic acid (3-PBA) levels between the last sample of the conventional treatment period (before the start of the organic treatment) and the last sample of organic treatment period. A one-sample t-test was used to assess whether the percent change was different than zero.
*Note: This test does not take into account the repeated measures for each participant and the organic treatment duration. The results of the linear-mixed effect models are the ones considered (reported in a section below) as they take into account the repeated measures for each participant and the organic treatment duration.
Measured: Last sample of the conventional period and the last sample of organic period, up to 40 days for each period
Overall Difference in Median 3-PBA Levels in Urine Between the Conventional and Organic Periods*
Overall difference in median 3-PBA levels between the conventional and organic periods. The overall differences in the medians of biomarkers between the conventional and the organic phase were assessed with the non-parametric Wilcoxon rank sum test on the creatinine-adjusted concentrations pooling all conventional samples (including the baseline) and the organic samples for all participants, regardless of the duration for which they followed the organic treatment.
*Note: This test does not take into account the repeated measures for each participant and the organic treatment duration. The results of the linear-mixed effect models are the ones considered (reported in a section below) as they take into account the repeated measures for each participant and the organic treatment duration.
Measured: 1 baseline sample, 2 samples in the conventional period (typical conventional diet) and 3 samples in the organic period, up to 40 days for each Period
Effect of Organic Treatment in 3-PBA Levels in Urine, Taking in Account the Repeated Measures and Duration of Organic Period
A linear mixed-effect regression model was fitted for 3-PBA (log-transformed, creatinine-adjusted). The model accounted for the duration and the effect of treatment. It included student-level (repeated measures within person) and school-level (multiple students clustered within each school) random intercepts with an unstructured covariance matrix. Continuous variables, other than time (days of treatment), were centered at the population means. The model included fixed effects for treatment condition (organic or conventional) and time (days of treatment), where time = 0 was used for the start of the treatment. The model was adjusted for the baseline value (first urine sample for all children) of the outcome to account for the background participant levels. An interaction term for time and treatment was considered and subsequently dropped if it did not meet the threshold of p-value<0. 05.
Measured: 1 baseline sample, 2 samples in the conventional period (typical conventional diet) and 3 samples in the organic period, up to 40 days for each Period
Overall Difference in Median 6-chloronicotininc Acid (6-CN) Levels in Urine Between the Conventional and Organic Periods*
Overall difference in median 6-CN levels between the conventional and organic periods. The overall differences in the medians of biomarkers between the conventional and the organic phase were assessed with the non-parametric Wilcoxon rank sum test on the creatinine-adjusted concentrations pooling all conventional samples (including the baseline) and the organic samples for all participants, regardless of the duration for which they followed the organic treatment.
*Note: This test does not take into account the repeated measures for each participant and the organic treatment duration. The results of the linear-mixed effect models are the ones considered (reported in a section below) as they take into account the repeated measures for each participant and the organic treatment duration.
Measured: 1 baseline sample, 2 samples in the conventional period (typical conventional diet) and 3 samples in the organic period, up to 40 days for each Period
Effect of Organic Treatment in 6-CN Levels in Urine, Taking in Account the Repeated Measures and Duration of Organic Period - Odds Ratio Calculated Based on the Fit of a Logistic Mixed-effect Model
A logistic model was fitted for 6-CN (binary variable; above and below LOD) due to the high number of values below LOD. The model accounted for the duration and the effect of treatment. It included student-level (repeated measures within person) and school-level (multiple students clustered within each school) random intercepts with an unstructured covariance matrix. Continuous variables, other than time (days of treatment), were centered at the population means. The model included fixed effects for treatment condition (organic or conventional) and time (days of treatment), where time = 0 was used for the start of the treatment. The model was adjusted for the baseline value (first urine sample for all children) of the outcome to account for the background participant levels. An interaction term for time and treatment was considered and subsequently dropped if it did not meet the threshold of p-value<0. 05.
Measured: 1 baseline sample, 2 samples in the conventional period (typical conventional diet) and 3 samples in the organic period, up to 40 days for each Period
Secondary outcomes (9)
Change in Oxidative Stress/Inflammation Biomarker 8-OHdG Levels in Urine Between Organic and Conventional Periods*
Percent change in oxidative stress/inflammation biomarker 8-OHdG levels between the last sample of the conventional treatment period (before the start of the organic treatment) and the last sample of organic treatment period. A one-sample t-test was used to assess whether the percent change was different than zero.
*Note: This test does not take into account the repeated measures for each participant and the organic treatment duration. The results of the linear-mixed effect models are the ones considered (reported in a section below) as they take into account the repeated measures for each participant and the organic treatment duration.
Measured: Last sample of the conventional period and the last sample of organic period, up to 40 days for each period
Overall Difference in Median 8-OHdG Levels in Urine Between the Conventional and Organic Periods*
Overall difference in median 8-OHdG levels between the conventional and organic periods. The overall differences in the medians of biomarkers between the conventional and the organic phase were assessed with the non-parametric Wilcoxon rank sum test on the creatinine-adjusted concentrations pooling all conventional samples (including the baseline) and the organic samples for all participants, regardless of the duration for which they followed the organic treatment.
*Note: This test does not take into account the repeated measures for each participant and the organic treatment duration. The results of the linear-mixed effect models are the ones considered (reported in a section below) as they take into account the repeated measures for each participant and the organic treatment duration.
Measured: 1 baseline sample, 2 samples in the conventional period (typical conventional diet) and 3 samples in the organic period, up to 40 days for each Period
Effect of Organic Treatment in 8-OHdG Levels in Urine, Taking in Account the Repeated Measures and Duration of Organic Period
A linear mixed-effect regression model was fitted for 8-OHdG (log-transformed, creatinine-adjusted). The model accounted for the duration and the effect of treatment. It included student-level (repeated measures within person) and school-level (multiple students clustered within each school) random intercepts with an unstructured covariance matrix. Continuous variables, other than time (days of treatment), were centered at the population means. The model included fixed effects for treatment condition (organic or conventional) and time (days of treatment), where time = 0 was used for the start of the treatment. The model was adjusted for the baseline value (first urine sample for all children) of the outcome to account for the background participant levels. An interaction term for time and treatment was considered and subsequently dropped if it did not meet the threshold of p-value<0. 05.
Measured: 1 baseline sample, 2 samples in the conventional period (typical conventional diet) and 3 samples in the organic period, up to 40 days for each Period
Change in Oxidative Stress/Inflammation Biomarker 8-iso-PGF2a Levels in Urine Between Organic and Conventional Periods*
Percent change in oxidative stress/inflammation biomarker 8-iso-PGF2a levels between the last sample of the conventional treatment period (before the start of the organic treatment) and the last sample of organic treatment period. A one-sample t-test was used to assess whether the percent change was different than zero.
*Note: This test does not take into account the repeated measures for each participant and the organic treatment duration. The results of the linear-mixed effect models are the ones considered (reported in a section below) as they take into account the repeated measures for each participant and the organic treatment duration.
Measured: Last sample of the conventional period and the last sample of organic period, up to 40 days for each period
Overall Difference in Median 8-iso-PGF2a Levels in Urine Between the Conventional and Organic Periods*
Overall difference in median 8-iso-PGF2a levels between the conventional and organic periods. The overall differences in the medians of biomarkers between the conventional and the organic phase were assessed with the non-parametric Wilcoxon rank sum test on the creatinine-adjusted concentrations pooling all conventional samples (including the baseline) and the organic samples for all participants, regardless of the duration for which they followed the organic treatment.
*Note: This test does not take into account the repeated measures for each participant and the organic treatment duration. The results of the linear-mixed effect models are the ones considered (reported in a section below) as they take into account the repeated measures for each participant and the organic treatment duration.
Measured: 1 baseline sample, 2 samples in the conventional period (typical conventional diet) and 3 samples in the organic period, up to 40 days for each Period
Effect of Organic Treatment in 8-iso-PGF2a Levels in Urine, Taking in Account the Repeated Measures and Duration of Organic Period
A linear mixed-effect regression model was fitted for 8-iso-PGF2a (log-transformed, creatinine-adjusted). The model accounted for the duration and the effect of treatment. It included student-level (repeated measures within person) and school-level (multiple students clustered within each school) random intercepts with an unstructured covariance matrix. Continuous variables, other than time (days of treatment), were centered at the population means. The model included fixed effects for treatment condition (organic or conventional) and time (days of treatment), where time = 0 was used for the start of the treatment. The model was adjusted for the baseline value (first urine sample for all children) of the outcome to account for the background participant levels. An interaction term for time and treatment was considered and subsequently dropped if it did not meet the threshold of p-value<0. 05.
Measured: 1 baseline sample, 2 samples in the conventional period (typical conventional diet) and 3 samples in the organic period, up to 40 days for each Period
Change in Oxidative Stress/Inflammation Biomarker MDA Levels in Urine Between Organic and Conventional Periods*
Percent change in oxidative stress/inflammation biomarker MDA levels between the last sample of the conventional treatment period (before the start of the organic treatment) and the last sample of organic treatment period. A one-sample t-test was used to assess whether the percent change was different than zero.
*Note: This test does not take into account the repeated measures for each participant and the organic treatment duration. The results of the linear-mixed effect models are the ones considered (reported in a section below) as they take into account the repeated measures for each participant and the organic treatment duration.
Measured: Last sample of the conventional period and the last sample of organic period, up to 40 days for each period
Overall Difference in Median MDA Levels in Urine Between the Conventional and Organic Periods*
Overall difference in median MDA levels between the conventional and organic periods. The overall differences in the medians of biomarkers between the conventional and the organic phase were assessed with the non-parametric Wilcoxon rank sum test on the creatinine-adjusted concentrations pooling all conventional samples (including the baseline) and the organic samples for all participants, regardless of the duration for which they followed the organic treatment.
*Note: This test does not take into account the repeated measures for each participant and the organic treatment duration. The results of the linear-mixed effect models are the ones considered (reported in a section below) as they take into account the repeated measures for each participant and the organic treatment duration.
Measured: 1 baseline sample, 2 samples in the conventional period (typical conventional diet) and 3 samples in the organic period, up to 40 days for each Period
Effect of Organic Treatment in MDA Levels in Urine, Taking in Account the Repeated Measures and Duration of Organic Period
A linear mixed-effect regression model was fitted for MDA (log-transformed, creatinine-adjusted). The model accounted for the duration and the effect of treatment. It included student-level (repeated measures within person) and school-level (multiple students clustered within each school) random intercepts with an unstructured covariance matrix. Continuous variables, other than time (days of treatment), were centered at the population means. The model included fixed effects for treatment condition (organic or conventional) and time (days of treatment), where time = 0 was used for the start of the treatment. The model was adjusted for the baseline value (first urine sample for all children) of the outcome to account for the background participant levels. An interaction term for time and treatment was considered and subsequently dropped if it did not meet the threshold of p-value<0. 05.
Measured: 1 baseline sample, 2 samples in the conventional period (typical conventional diet) and 3 samples in the organic period, up to 40 days for each Period
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted20 Dec 2016 (estimated)
- Study start3 Jan 2017
- Primary completion18 Apr 2017
- Study completion18 Apr 2017
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for Oxidative StressStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind
- Who is masked
- Investigator
- Enrolment
- 191 participants (actual)
Sponsor and investigators
- Lead sponsor
- Cyprus University of Technology
- Sponsor type
- University, hospital or other
- Collaborators
- European Commission
- Responsible party
- Principal investigator, Konstantinos Makris, Cyprus University of Technology
- Investigators
- Konstantinos C Makris, Study director, Cyprus University of Technology
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02998203
- Sponsor's protocol ID
- CyprusUT
- Acronym
- ORGANIKO
- Status last verified
- Sep 2023
- First submitted
- 14 Dec 2016
- Last updated
- 7 Sep 2023
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- Yes
- Individual data sharing
- Yes: Following the publication of the manuscript, all relevant info is made available to the public.
Publications
Makris KC, Konstantinou C, Andrianou XD, Charisiadis P, Kyriacou A, Gribble MO, Christophi CA. A cluster-randomized crossover trial of organic diet impact on biomarkers of exposure to pesticides and biomarkers of oxidative stress/inflammation in primary school children. PLoS One. 2019 Sep 4;14(9):e0219420. doi: 10.1371/journal.pone.0219420. eCollection 2019.
PubMed 31483785Konstantinou C, Gaengler S, Oikonomou S, Delplancke T, Charisiadis P, Makris KC. Use of metabolomics in refining the effect of an organic food intervention on biomarkers of exposure to pesticides and biomarkers of oxidative damage in primary school children in Cyprus: A cluster-randomized cross-over trial. Environ Int. 2022 Jan;158:107008. doi: 10.1016/j.envint.2021.107008. Epub 2021 Nov 30.
PubMed 34991267
Study at a glance
From the registry record, last updated by the sponsor on 7 Sep 2023. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Organic Diet and Children's Health - ORGANIKO LIFE+
- ClinicalTrials.gov ID
- NCT02998203
- Acronym / sponsor ID
- ORGANIKO / CyprusUT
- Conditions
- Oxidative Stress, Inflammation
- Keywords
- organic diet, health, pesticides, inflammation biomarkers, oxidative stress biomarkers
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 191 participants (actual)
- Lead sponsor
- Cyprus University of TechnologyUniversity, hospital or other
- Collaborators
- European Commission
- Study start
- 3 Jan 2017 (actual)
- Primary completion
- 18 Apr 2017 (actual)
- Study completion
- 18 Apr 2017 (actual)
- First posted
- 20 Dec 2016 (estimated)
- Results
- Posted 7 Sep 2023
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind (investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Conventional phase | No intervention | –During the conventional phase, participants are asked to maintain their usual dietary choices for 40 days. |
| Organic phase | Experimental | Dietary Supplement: Organic dietDuring the organic phase, participants are asked to follow strictly the two 20-day organic dietary menus provided to them for 40 days. The organic dietary menus were prepared by a certified dietitian. The meals of the organic phase are prepared by a certified organic restaurant and are delivered to school every day except Sunday. For the meals of breakfast and afternoon snacks, children choose their preferred options for the week on the Friday of the previous week according to a list of organic food items and the products for these meals are delivered on Saturday along with the rest meals. Parents are responsible to pick-up the organic meals from school and ensure that the participating children have access to them. |
Who may qualify
- Ages
- 10 to 12 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child
Key inclusion criteria (1 listed)
- Healthy children aged 10-12 years, residing in Cyprus over the last five years who consume primarily (> 80%) conventional food (non-organic).
Key exclusion criteria (1 listed)
- Children with chronic conditions (e.g. diabetes, asthma) or allergies in food (e.g. gluten, lactose tolerance)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Organic dietFull 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. | Dietary supplement | Organic phase |
Primary outcome
Change in Pesticide Metabolite 3-phenoxybenzoic Acid (3-PBA) Levels in Urine Between Organic and Conventional Periods*
Time frame: Last sample of the conventional period and the last sample of organic period, up to 40 days for each period
Percent change in pesticide metabolite 3-phenoxybenzoic acid (3-PBA) levels between the last sample of the conventional treatment period (before the start of the organic treatment) and the last sample of organic treatment period. A one-sample t-test was used to assess whether the percent change was different than zero. *Note: This test does not take into account the repeated measures for each participant and the organic treatment duration. The results of the linear-mixed effect models are the ones considered (reported in a section below) as they take into account the repeated measures for each participant and the organic treatment duration.
Overall Difference in Median 3-PBA Levels in Urine Between the Conventional and Organic Periods*
Time frame: 1 baseline sample, 2 samples in the conventional period (typical conventional diet) and 3 samples in the organic period, up to 40 days for each Period
Overall difference in median 3-PBA levels between the conventional and organic periods. The overall differences in the medians of biomarkers between the conventional and the organic phase were assessed with the non-parametric Wilcoxon rank sum test on the creatinine-adjusted concentrations pooling all conventional samples (including the baseline) and the organic samples for all participants, regardless of the duration for which they followed the organic treatment. *Note: This test does not take into account the repeated measures for each participant and the organic treatment duration. The results of the linear-mixed effect models are the ones considered (reported in a section below) as they take into account the repeated measures for each participant and the organic treatment duration.
Effect of Organic Treatment in 3-PBA Levels in Urine, Taking in Account the Repeated Measures and Duration of Organic Period
Time frame: 1 baseline sample, 2 samples in the conventional period (typical conventional diet) and 3 samples in the organic period, up to 40 days for each Period
A linear mixed-effect regression model was fitted for 3-PBA (log-transformed, creatinine-adjusted). The model accounted for the duration and the effect of treatment. It included student-level (repeated measures within person) and school-level (multiple students clustered within each school) random intercepts with an unstructured covariance matrix. Continuous variables, other than time (days of treatment), were centered at the population means. The model included fixed effects for treatment condition (organic or conventional) and time (days of treatment), where time = 0 was used for the start of the treatment. The model was adjusted for the baseline value (first urine sample for all children) of the outcome to account for the background participant levels. An interaction term for time and treatment was considered and subsequently dropped if it did not meet the threshold of p-value<0. 05.
Overall Difference in Median 6-chloronicotininc Acid (6-CN) Levels in Urine Between the Conventional and Organic Periods*
Time frame: 1 baseline sample, 2 samples in the conventional period (typical conventional diet) and 3 samples in the organic period, up to 40 days for each Period
Overall difference in median 6-CN levels between the conventional and organic periods. The overall differences in the medians of biomarkers between the conventional and the organic phase were assessed with the non-parametric Wilcoxon rank sum test on the creatinine-adjusted concentrations pooling all conventional samples (including the baseline) and the organic samples for all participants, regardless of the duration for which they followed the organic treatment. *Note: This test does not take into account the repeated measures for each participant and the organic treatment duration. The results of the linear-mixed effect models are the ones considered (reported in a section below) as they take into account the repeated measures for each participant and the organic treatment duration.
Effect of Organic Treatment in 6-CN Levels in Urine, Taking in Account the Repeated Measures and Duration of Organic Period - Odds Ratio Calculated Based on the Fit of a Logistic Mixed-effect Model
Time frame: 1 baseline sample, 2 samples in the conventional period (typical conventional diet) and 3 samples in the organic period, up to 40 days for each Period
A logistic model was fitted for 6-CN (binary variable; above and below LOD) due to the high number of values below LOD. The model accounted for the duration and the effect of treatment. It included student-level (repeated measures within person) and school-level (multiple students clustered within each school) random intercepts with an unstructured covariance matrix. Continuous variables, other than time (days of treatment), were centered at the population means. The model included fixed effects for treatment condition (organic or conventional) and time (days of treatment), where time = 0 was used for the start of the treatment. The model was adjusted for the baseline value (first urine sample for all children) of the outcome to account for the background participant levels. An interaction term for time and treatment was considered and subsequently dropped if it did not meet the threshold of p-value<0. 05.
9 secondary outcomes
Change in Oxidative Stress/Inflammation Biomarker 8-OHdG Levels in Urine Between Organic and Conventional Periods*
Time frame: Last sample of the conventional period and the last sample of organic period, up to 40 days for each period
Overall Difference in Median 8-OHdG Levels in Urine Between the Conventional and Organic Periods*
Time frame: 1 baseline sample, 2 samples in the conventional period (typical conventional diet) and 3 samples in the organic period, up to 40 days for each Period
Effect of Organic Treatment in 8-OHdG Levels in Urine, Taking in Account the Repeated Measures and Duration of Organic Period
Time frame: 1 baseline sample, 2 samples in the conventional period (typical conventional diet) and 3 samples in the organic period, up to 40 days for each Period
Change in Oxidative Stress/Inflammation Biomarker 8-iso-PGF2a Levels in Urine Between Organic and Conventional Periods*
Time frame: Last sample of the conventional period and the last sample of organic period, up to 40 days for each period
Overall Difference in Median 8-iso-PGF2a Levels in Urine Between the Conventional and Organic Periods*
Time frame: 1 baseline sample, 2 samples in the conventional period (typical conventional diet) and 3 samples in the organic period, up to 40 days for each Period
Effect of Organic Treatment in 8-iso-PGF2a Levels in Urine, Taking in Account the Repeated Measures and Duration of Organic Period
Time frame: 1 baseline sample, 2 samples in the conventional period (typical conventional diet) and 3 samples in the organic period, up to 40 days for each Period
Change in Oxidative Stress/Inflammation Biomarker MDA Levels in Urine Between Organic and Conventional Periods*
Time frame: Last sample of the conventional period and the last sample of organic period, up to 40 days for each period
Overall Difference in Median MDA Levels in Urine Between the Conventional and Organic Periods*
Time frame: 1 baseline sample, 2 samples in the conventional period (typical conventional diet) and 3 samples in the organic period, up to 40 days for each Period
Effect of Organic Treatment in MDA Levels in Urine, Taking in Account the Repeated Measures and Duration of Organic Period
Time frame: 1 baseline sample, 2 samples in the conventional period (typical conventional diet) and 3 samples in the organic period, up to 40 days for each Period
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 7 Sep 2023.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Results publication: PubMed 31483785Makris KC, Konstantinou C, Andrianou XD, Charisiadis P, Kyriacou A, Gribble MO, Christophi CA. A cluster-randomized crossover trial of organic diet impact on biomarkers of exposure to pesticides and biomarkers of oxidative stress/inflammation in primary school children. PLoS One. 2019 Sep 4;14(9):e0219420. doi: 10.1371/journal.pone.0219420. eCollection 2019.
- Derived from this study: PubMed 34991267Konstantinou C, Gaengler S, Oikonomou S, Delplancke T, Charisiadis P, Makris KC. Use of metabolomics in refining the effect of an organic food intervention on biomarkers of exposure to pesticides and biomarkers of oxidative damage in primary school children in Cyprus: A cluster-randomized cross-over trial. Environ Int. 2022 Jan;158:107008. doi: 10.1016/j.envint.2021.107008. Epub 2021 Nov 30.
- Individual participant dataSharing planned: Yes. Following the publication of the manuscript, all relevant info is made available to the public.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Konstantinos C Makris study director
Cyprus University of Technology
Questions about this trial
What is this clinical trial studying?
A study testing Organic diet in people with Oxidative Stress and Inflammation, run by Cyprus University of Technology.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 7 Sep 2023. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Yes. Results are posted in the registry (first posted 7 Sep 2023). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in Pesticide Metabolite 3-phenoxybenzoic Acid (3-PBA) Levels in Urine Between Organic and Conventional Periods* (time frame: Last sample of the conventional period and the last sample of organic period, up to 40 days for each period). The study lists 5 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT02998203, which also lists 2 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 7 Sep 2023.