The effects of organic food on human health: a systematic review and meta-analysis of population-based studies

Correspondence: A. Zhao, Vanke School of Public Health, Tsinghua University, No. 30, Shuangqing Road, Haidian District, Beijing 100084, People’s Republic of China. E-mail: aizhao18@tsinghua.edu.cn.

Nutrition Reviews, Volume 82, Issue 9, September 2024, Pages 1151–1175, https://doi.org/10.1093/nutrit/nuad124

Cite

Bibo Jiang, Jinzhu Pang, Junan Li, Lijuan Mi, Dongmei Ru, Jingxi Feng, Xiaoxu Li, Ai Zhao, Li Cai, The effects of organic food on human health: a systematic review and meta-analysis of population-based studies, Nutrition Reviews, Volume 82, Issue 9, September 2024, Pages 1151–1175, https://doi.org/10.1093/nutrit/nuad124

Abstract

Although the nutritional composition of organic food has been thoroughly researched, there is a dearth of published data relating to its impact on human health.

This systematic review aimed to examine the association between organic food intake and health effects, including changes in in vivo biomarkers, disease prevalence, and functional changes.

PubMed, EMBASE, Web of Science, the Cochrane Library, and ClinicalTrials.gov were searched from inception through Nov 13, 2022.

Both observational and interventional studies conducted in human populations were included, and association between level of organic food intake and each outcome was quantified as “no association,” “inconsistent,” “beneficial correlation/harmful correlation,” or “insufficient”. For outcomes with sufficient data reported by at least 3 studies, meta-analyses were conducted, using random-effects models to calculate standardized mean differences.

Based on the included 23 observational and 27 interventional studies, the association between levels of organic food intake and (i) pesticide exposure biomarker was assessed as “beneficial correlation,” (ii) toxic metals and carotenoids in the plasma was assessed as “no association,” (iii) fatty acids in human milk was assessed as “insufficient,” (iv) phenolics was assessed as “beneficial”, and serum parameters and antioxidant status was assessed as “inconsistent”. For diseases and functional changes, there was an overall “beneficial” association with organic food intake, and there were similar findings for obesity and body mass index. However, evidence for association of organic food intake with other single diseases was assessed as “insufficient” due to the limited number and extent of studies.

Organic food intake was found to have a beneficial impact in terms of reducing pesticide exposure, and the general effect on disease and functional changes (body mass index, male sperm quality) was appreciable. More long-term studies are required, especially for single diseases.

PROSPERO registration no. CRD42022350175.

INTRODUCTION

Organic agriculture is an ecological production management system that emphasizes rotating crops, managing pests naturally, diversifying crops and livestock, and improving the soil with compost additions and animal and green manures. 1 All food sold as organic must be certified as such by approved organic food control bodies according to defined criteria. 2 With an increase of 14 billion euros, in 2020 the global market for organic food saw its largest year of growth ever, surpassing 120 billion euros. 1

Belief that organic food is healthier than conventional food is one of the key reasons why people consume it. 3 Organic farming imposes restrictions on the use of antibiotics and pesticides. Several research groups have explored differences in pesticide residue concentrations between organic and conventional products, their findings indicating that organic production results in lower levels of pesticide residues. 4–6 Moreover, organic food may contain more beneficial nutrients or phytochemicals. Organic milk has higher concentrations of beneficial fatty acids compared with conventional milk, 7 , 8 and higher levels of polyphenols have been detected in organically grown tomatoes, blue honeysuckle, and apples. 9 , 10

However, the potential health benefits of organic food remain unclear. Previous systematic reviews have mostly focused on differences in nutrition or pesticide residue concentrations between conventionally produced foods and those produced using organic agriculture. Some meta-analyses have concluded that organic food has a lower risk of being contaminated with detectable pesticide residues, and that there are higher PUFA levels in organic meat. 4 , 11 Średnicka-Tobe et al aimed to determine the direct health effects of organic food intake, but were unable to perform a quantitative analysis due to the lack of studies and high level of heterogeneity in those studies. 11 Another systematic review expanded the breadth of the evidence examined related to human health outcomes, including potential changes in the preclinical stage, such as total antioxidant status, carotenoids, but no quantitative results were obtained. 12 A recent meta-analysis found that organic food consumption was associated with a modest reduction (11%) in the risk of obesity. 13 However, the meta-analysis only focused on obesity, and the 4 included studies were observational only and of moderate quality, with significant heterogeneity.

Thus, there is a need for further investigation of the potential health effects of organic food, especially given the growing consciousness among consumers of the environmental impacts of food production. The present study aimed to examine the direct clinical impact of organic food intake on human health by including assessment of potential preclinical biomarker changes in vivo, detectable functional changes, and disease outcomes. Furthermore, classification criteria were established to categorize the association between the consumption of organic food and health outcomes.

METHODS

Search strategy

The review was registered with PROSPERO (CRD42022350175) and reported using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. 14 Four electronic databases (PubMed, EMBASE, Cochrane, and Web of Science) were searched for relevant studies from their years of inception up to November 13, 2022. The gray literature was searched on ClinicalTrials.gov to avoid publication bias. Individualized search strategies for the various databases included combinations of terms related to organic food and health outcomes. An example search strategy can be found in Appendix S1 in the Supporting Information online.

Inclusion and exclusion criteria

Both observational and interventional studies performed in humans were identified. The route of intervention/exposure to organic food was limited to dietary intake, and there was no restriction on the food type. For inclusion, studies needed to report differences in outcomes between groups, or risk estimates (odds ratio [OR], relative ratio [RR] or hazard ratio [HR]) for organic food intake. Outcomes studied included diseases (body mass index [BMI] and male sperm quality), in vivo biomarkers, and physiological biochemical parameters. Only English language articles were included. Studies were excluded if there was no description about the route of exposure to / intervention with organic food ( Table 1).

PICOS criteria for inclusion of studies

PICOS criteria for inclusion of studies

Data extraction

Title scans and abstract reviews were conducted by 2 investigators independently, and the full text of all included studies was evaluated based on the inclusion and exclusion criteria. Discrepancies were resolved by discussion until a consensus was reached. Data were extracted by a research assistant (J.B.) and checked by another reviewer (L.X.). Information describing the study sample (sample size, age, sex, geographic region, and health condition), study design (study type, exposure or intervention duration, groups, and organic food types), and outcomes (specimen types, outcome indicators, and conclusions) were extracted. Moreover, the values of outcome indicators before and after the intervention in the single interventional study (at baseline and follow-up in cohort studies) were collected, including the subgroup data.

Risk-of-bias assessment

The risk of bias of the clinical trial study was assessed using the The Cochrane Risk of Bias Assessment Tool. 15 The observational studies were assessed using the Newcastle–Ottawa Quality Assessment Form and the Specialist Unit for Review Evidence (SURE) checklist. 16 , 17 Two reviewers participated in the assessment of bias risk, and any disagreement was settled by discussion.

Data synthesis and meta-analyses

Outcomes were categorized into 2 categories: (I) biomarkers (pesticide exposure; toxic metals; fatty acids in human milk; nutrients in plasma; serum parameters; and total antioxidant status) and (II) disease and functional change (BMI, male sperm quality).

The included studies were coded and the data subsequently classified and summarized to determine the associations between organic food intake and outcomes ( Table 2); the coding and classification method used was first described by James. 18 Briefly, the evidence for an association was defined as “insufficient” if it was indicated by 3 or fewer studies. If the association was indicated by more than 3 studies, the results were classified based on the percentage of studies reporting statistically significant results as follows: (1) “no association” if less than 30% of the studies reported a significant association; (2) “inconsistent” if the significant association was reported in 34% to 59% of the studies; (3) “beneficial/harmful correlation” if over 60% of the studies reported a significant association. Whether the correlation was considered beneficial or harmful was based on the direction of the reported correlation. The “beneficial/harmful correlation” assessment was not completely equivalent to the assessment of “positive/negative correlation” between organic food and outcomes. For example, when the outcome was pesticide exposure, a “beneficial correlation” indicated that organic food consumption led to a reduction in pesticide exposure (a numerically negative correlation). The same coding was also applied to the subgroup analysis of study type to examine whether the findings were influenced or not.

Classifying criteria for association level between organic food intake and outcomes

The correlation was rated as a “Beneficial correlation” when the organic food was associated with a more favourable outcome; otherwise, it was rated as a “Harmful correlation”.

Classifying criteria for association level between organic food intake and outcomes

The correlation was rated as a “Beneficial correlation” when the organic food was associated with a more favourable outcome; otherwise, it was rated as a “Harmful correlation”.

All analyses were performed using Stata software version 14.2, and standardized mean differences (SMDs) were calculated using random-effects models for outcomes with at least 3 studies reporting sufficient data. Differences were calculated as levels for the organic diet group minus levels for the conventional diet group. Heterogeneity was determined using Cochran’s Q statistic and I 2 values (I 2 values of 25, 50, and 75 were considered as indicating low, moderate, and high heterogeneity, respectively).

RESULTS

Literature search and study characteristics

A total of 13 060 relevant articles were identified after searching. Following the removal of duplicates and initial screening of titles and/or abstracts, 50 studies were included ( Figure 1). 19–68 Twenty-seven of the included studies were interventional trials and used traditional food as a control diet. 18–30 , 46 , 49 , 52 , 53 , 55–58 , 60 , 61 , 63 , 65–67 Most of the studies were conducted in Europe 18–23 , 26–28 , 30–45 , 50–53 , 55 , 57 , 62 , 64 , 66 , 67 and the United States 24 , 25 , 45–48 , 54 , 59–61 , 63 , 65 ; 2 were conducted in Brazil, 29 , 56 1 in Japan, 58 and 1 in Australia. 49 Eleven studies were conducted in children, 24 , 25 , 40 , 41 , 46 , 48 , 53 , 60 , 64 , 65 , 67 4 were in pregnant women, 35–37 , 51 and 2 were in senior men. 54 , 59 The main characteristics of the included studies are summarized ( Table 3), 18–67 and the results of the classification of the association levels are shown in Table 4. 18–67 The subgroup analysis of the study types is presented in Table 5. 18–67 The results of the risk-of-bias assessment indicate that more than half of the trials had a high risk of bias in terms of blinding. The reporting bias of the majority of the trials was assessed as low risk (see Figure S1 in the Supporting Information online).

Flowchart of search and selection process.

Main characteristics of studies examining the health effects of organic food on humans

• Parallel single-blind RCT;
• 20;
• France;
• Healthy nonsmoking females (21 y–39 y)

• Tomato puree;
• Blood

• Group 1: organic tomato puree;
• Group 2: conventional tomato puree

• Parallel double-blind RCT;
• 36;
• Germany;
• Healthy males (19 y–54 y)

• Blanched carrots;
• Blood

• Group 1: organic carrots;
• Group 2: conventional carrots;
• Group 3: followed the carotenoid-restricted diet

• Crossover double-blind RCT;
• 43;
• Germany;
• Nonsmoking healthy men (22 y–40 y)

• Apple;
• Blood

• Group 1 (n = 16): organic apples
• Group 2 (n = 16): conventional apples
• Group 3 (n = 11): maintained an apple- and polyphenol-restricted diet

• Double-blinded, crossover RCT;
• 6;
• Germany;
• Nonsmoking healthy men (23 y–32 y)

• Apple;
• Blood

• Group 1: organic apples
• Group 2: conventional apples

• Double-blinded, crossover RCT;
• 16;
• Denmark;
• Healthy adults (21 y–35 y)

• 4 different menus including common vegetables, fruits, grains, a few eggs, and meat;
• Blood and urine

• Group 1: organic diets followed by conventional diets;
• Group 2: conventional diets followed by organic diets

• Nonrandomized self-controlled interventional trials;
• 8;
• Turkey;
• Healthy non-smokers (24 y–45 y)

• Wine;
• Blood

• Nonrandomized self-controlled interventional trials;
• 23;
• United States;
• Children (3 y–11 y)

• Fruits, vegetables, and grains;
• Urine

• Nonrandomized self-controlled interventional trials;
• 23;
• United States;
• Children (3 y–11 y)

• Fresh fruits and vegetables, juices, processed fruits or vegetables, and some wheat- or corn-based items;
• Urine and saliva

• Nonrandomized self-controlled interventional trials;
• 10;
• Italy;
• Healthy nonsmoking men (30 y–65 y)

• Fruits, vegetables, red wine, and milk;
• Blood

• Cross-interventional trial;
• 150;
• Italy;
• Healthy nonsmokers (30 y–65 y) and CKD patients (42 y–54 y)

• Organic vegetables and fruits; Italian Mediterranean Diet was used;
• Fasting blood and urine

• Group 1 (n = 100): healthy subjects;
• Group 2 (n = 50): CKD patients

• Double-blinded, cross-over RCT;
• 18;
• Denmark;
• Healthy, nonsmoking, adult men (18 y–40 y)

• Crop foods, including fava beans, potatoes, rape seeds, and wheat;
• Fasting blood

• Group 1 (n = 6): OA diet;
• Group 2 (n = 6): OB diet;
• Group 3 (n = 6): C diet

• Carotenoid
• Content

• Crossover RCT;
• 24;
• Brazil;
• Nonsmoking, healthy subjects (20 y–55 y)

• 400 ml red grape juices;
• Fasting blood

• Group 1 (n = 8): organic red grape juice;
• Group 2 (n = 8): conventional red grape juice;
• Group 3 (n = 8): water

• Nonrandomized self-controlled interventional trials;
• 2;
• Switzerland;
• Adults (46 y–49 y)

• Not explicitly stated;
• Urine

• Cross-sectional study;
• 196;
• Denmark;
• Adult healthy men (mean age 33 y)

• Not explicitly stated;
• Sperm

• Group 1 (n = 55): members of 2 associations promoting the development of organic agriculture;
• Group 2 (n = 141): men working in an airline company

• Cross-sectional study;
• 256;
• Denmark;
• Male farmers (mean age 38 y)

• Fruit, vegetables meat, milk, and bread;
• Sperm

• Group N (n = 166): organic intake = 0%;
• Group M (n = 39): organic intake = 1%–49%;
• Group H (n = 46): organic intake = 50%–100%

• Prospective observational cohort study;
• 68 946;
• France;
• Adults (mean age 44.2 y)

• 16 labeled organic products b ;
• NS

• Cohort study;
• 300;
• France;
• Adults (mean age 58 y)

• 264 food and beverage items;
• Urine

• Group 1 (n = 150): low organic food consumers;
• Group 2 (n = 150): high organic food consumers

• Prospective pregnancy cohort study;
• 35 107;
• Norway;
• Pregnant women who delivered a singleton male infant

• Group 1 (n = 17 996): never/seldom consume organic food;
• Group 2 (n = 17 111): sometimes, often, or mostly consume organic food

• Prospective pregnancy cohort study;
• 28 192;
• Norway;
• Nulliparous pregnant females (mean age 28 y)

• 6 food groups: milk and dairy products, bread and cereal products, eggs, vegetables, fruit, and meat;
• NS

• Group low (n = 25 699): never/seldom consume organic food;
• Group high (n = 2493): sometimes/often/mostly consume organic food

• Retrospective case–control study;
• 612;
• Denmark;
• Mothers of boys

• Milk, other dairy products, eggs, meat, fruit, and vegetables;
• NS

• Group 1 (n = 306): mothers of boys operated on for hypospadias;
• Group 2 (n = 306): matching control group

• Prospective birth cohort study;
• 312;
• Netherlands;
• Breastfeeding mothers (mean age 33 y)

• Dairy and meat products;
• Breast milk samples collected 1 mo postpartum

• Group 1 (n = 186): conventional,
• Group 2 (n = 33): 50%–90% organic food consumption;
• Group 3 (n = 37): 90% organic food consumption

• Prospective birth cohort study;
• 310;
• Netherlands;
• Breastfeeding mothers (mean age 33 y)

• Meat and dairy products;
• Breast milk samples collected 1 mo postpartum

• Group 1 (n = 185): conventional,
• Group 2 (n = 33): 50%–90% MDOO;
• Group 3 (n = 37): >90% MDOO

• Prospective observational cohort study;
• 1505;
• France;
• Infants (fetal period to 24 mo)

• Not explicitly stated;
• Urine of mothers

• Group 1 (n = 910): at least 1 otitis media (OM) episode;
• Group 2 (n = 408): at least 3 OM episodes

• Prospective birth cohort study;
• 2598;
• Netherlands;
• Children (mean age 2 y)

• Meat, eggs, vegetables, fruit, dairy products, bread, and/or dry products;
• Blood

• Group 1 (n = 2306): conventional diet (score below 21.0)
• Group 2 (n = 283): moderately organic food diet (score between 21.0 and 71.0);
• Group 3 (n = 175): strictly organic food diet (score above 71.0)

• Prospective observational cohort study;
• 62 224;
• France;
• Adults (mean age 45 y)

• 16 labeled organic products;
• NS

• Prospective cohort;
• 623 080;
• United Kingdom;
• Adult women (mean age 59 y)

• Not explicitly stated;
• NS

• Group 1 (n = 187 451): never consume organic food;
• Group 2 (n = 390 040): sometimes consumes organic food;
• Group 3 (n = 45 589): usually/always consume organic food

• Prospective observational cohort study;
• 8174;
• France;
• Adults (mean age 45 y)

• 16 labeled organic products;
• Blood

• Cross-sectional study;
• 41;
• United States;
• Breastfeeding healthy women 1 mo–3 mo postpartum (mean age was 26.8 y)

• Not explicitly stated;
• Urine and breast milk

• Group 1 (n = 17): organic dietary pattern;
• Group 2 (n = 23): conventional dietary pattern;

• Nonrandomized self-controlled interventional trials;
• 40;
• United States;
• Children (3 y–6 y)

• Fruits, bread, cereals, vegetables, dairy, eggs, juices, and snack foods;
• Urine

• Cross-sectional study;
• 240;
• United States;
• Adults with subclinical cardiovascular disease (45 y–84 y)

• Fruit and vegetables were specifically asked in questionnaires;
• Urine

• Group 1 (n = 80): “rarely or never” consume organic produce;
• Group 2 (n = 80): “sometimes” consume organic produce;
• Group 3 (n = 80): “often or always” consume organic produce

• Cross-sectional study;
• 39;
• United States;
• Children (2 y–5 y)

• Juice, fresh fruit, and vegetables;
• Urine

• Group 1 (n = 18): organic;
• Group 2 (n = 21): conventional;

• Single-blinded, crossover RCT;
• 13;
• Australia;
• Nonsmoking adults (18 y–65 y)

• Not explicitly stated;
• Urine

• Prospective observational cohort study;
• 300;
• France;
• Adults (mean age 58 y)

• 16 labeled organic products;
• Fasting blood

• Group 1 (n = 150): Nonorganic group (
• Group 2 (n = 150): Organic group (>50% of organic food in diet)

• Cross-sectional analysis;
• 2803;
• Switzerland
• Pregnant women

• Meat; eggs; vegetables; fruit; milk and milk products; bread; and dried foods (dried legumes and cereals);
• NS

• Group 1 (n = 2,766): women without GDM;
• Group 2 (n = 37): women with GDM;

• Randomized crossover interventional trial;
• 27;
• England;
• Healthy adults (21 y–36 y)

• Fruit, vegetables, and cereal products;
• Urine and blood

• Conventional group (n = 14): conventional MedDiet;
• Intervention group (n = 13): organic MedDiet

• Cluster-randomized crossover trial;
• 149;
• Cyprus;
• Children (11 y–12 y)

• Not explicitly stated;
• Urine

• Group 1 (n = 43): organic diet followed by conventional diet;
• Group 2 (n = 106): conventional diet followed by an organic diet

• Cross-sectional analysis;
• 3815;
• United States;
• Older adults (64.3 y ± .3 y)

• Milk, eggs, meat, fruit, vegetables, bread or cereals, frozen prepared meals, or other (specify);
• Blood

• Group 1 (n = 1,981): OF consumption (no);
• Group 2 (n = 1,738): OF consumption (yes)

• Crossover RCT;
• 19;
• Spain;
• Healthy people (18 y–40 y)

• Not explicitly stated;
• Blood and Urine

• Group 1 (n = 11): organic food diet followed by conventional diet;
• Group 2 (n = 8): conventional food diet followed by organic diet.

• Double-blind RCT;
• 13;
• Brazil;
• Adults with dyslipidemia (20 y–59 y)

• Juice made from BLS;
• Blood

• Group 1 (n = 5): placebo
• Group 2 (n = 6): BLS juice (low dose);
• Group 3 (n = 2): BLS juice (low dose).

• Long-term randomized interventional trial;
• 20;
• Idaho;
• Healthy pregnant women in early pregnancy (18 y–35 y)

• Fruits and vegetables;
• Urine

• Group 1 (n = 10): organic produce;
• Group 2 (n = 10): conventional produce

• Nonrandomized interventional trial;
• 103;
• Japan;
• (

• Not explicitly stated;
• Urine

• Group 1 (n = 36): organic diet for 5 d;
• Group 2 (n = 4): organic diet for 30 d;
• Group 3 (n = 63): conventional diet

• Cohort study;
• 271;
• United States;
• Senior men (mean age 53.3 y ± 17.6 y)

• Not mentioned;
• NS

• Nonrandomized self-controlled interventional trials;
• 16 participants from 4 families;
• United States;
• 7 adults (36 y–52 y) and 9 children (4 y–15 y)

• All beverages except water, all food categories, and oils, condiments, and spices (organic phase);
• Urine

• Nonrandomized self-controlled interventional trials;
• 16 participants from 4 families;
• United States;
• 7 adults (36 y–52 y) and 9 children (4 y–15 y)

• All beverages except water, all food categories, and oils, condiments, and spices (organic phase);
• Urine

• Cross-sectional analysis;
• 1775 children and 2121 adults;
• France

• A single-blind crossover randomized trial;
• 20;
• United States;
• Healthy lacto-ovo-vegetarian adults (age 38 y ± 3 y)

• Organic eggs;
• Blood

• Cohort study;
• 8081;
• France;
• Infants (age 2 mo–5.5 y)

• Not mentioned;
• NS

• Group 1 (n = 3162): infrequent CCF/infrequent OFs;
• Group 2 (n = 1314): infrequent CCF/frequent OFs;
• Group 3 (n = 2631): frequent CCF/infrequent OFs;
• Group 4 (n = 963): frequent CCF/frequent OFs

• Crossover trial;
• 23;
• United States;
• Children (3 y–11 y)

• Not mentioned;
• Urine

• Randomized crossover interventional trial;
• 27;
• England;
• Healthy adults (21 y–36 y)

• Fruit, vegetables, and cereal products;
• Urine and blood

• Conventional group (n = 14): conventional MedDiet;
• Intervention group (n = 13): organic MedDiet

• Cluster-randomized crossover trial;
• 149;
• Cyprus;
• Children (11 y–12 y)

• Not mentioned;
• Urine

• Group 1 (n = 43): organic diet followed by conventional diet;
• Group 2 (n = 106): conventional diet followed by an organic diet

• Parallel single-blind RCT;
• 20;
• France;
• Healthy nonsmoking females (21 y–39 y)

• Tomato puree;
• Blood

• Group 1: organic tomato puree;
• Group 2: conventional tomato puree

• Parallel double-blind RCT;
• 36;
• Germany;
• Healthy males (19 y–54 y)

• Blanched carrots;
• Blood

• Group 1: organic carrots;
• Group 2: conventional carrots;
• Group 3: followed the carotenoid-restricted diet

• Crossover double-blind RCT;
• 43;
• Germany;
• Nonsmoking healthy men (22 y–40 y)

• Apple;
• Blood

• Group 1 (n = 16): organic apples
• Group 2 (n = 16): conventional apples
• Group 3 (n = 11): maintained an apple- and polyphenol-restricted diet

• Double-blinded, crossover RCT;
• 6;
• Germany;
• Nonsmoking healthy men (23 y–32 y)

• Apple;
• Blood

• Group 1: organic apples
• Group 2: conventional apples

• Double-blinded, crossover RCT;
• 16;
• Denmark;
• Healthy adults (21 y–35 y)

• 4 different menus including common vegetables, fruits, grains, a few eggs, and meat;
• Blood and urine

• Group 1: organic diets followed by conventional diets;
• Group 2: conventional diets followed by organic diets

• Nonrandomized self-controlled interventional trials;
• 8;
• Turkey;
• Healthy non-smokers (24 y–45 y)

• Wine;
• Blood

• Nonrandomized self-controlled interventional trials;
• 23;
• United States;
• Children (3 y–11 y)

• Fruits, vegetables, and grains;
• Urine

• Nonrandomized self-controlled interventional trials;
• 23;
• United States;
• Children (3 y–11 y)

• Fresh fruits and vegetables, juices, processed fruits or vegetables, and some wheat- or corn-based items;
• Urine and saliva

• Nonrandomized self-controlled interventional trials;
• 10;
• Italy;
• Healthy nonsmoking men (30 y–65 y)

• Fruits, vegetables, red wine, and milk;
• Blood

• Cross-interventional trial;
• 150;
• Italy;
• Healthy nonsmokers (30 y–65 y) and CKD patients (42 y–54 y)

• Organic vegetables and fruits; Italian Mediterranean Diet was used;
• Fasting blood and urine

• Group 1 (n = 100): healthy subjects;
• Group 2 (n = 50): CKD patients

• Double-blinded, cross-over RCT;
• 18;
• Denmark;
• Healthy, nonsmoking, adult men (18 y–40 y)

• Crop foods, including fava beans, potatoes, rape seeds, and wheat;
• Fasting blood

• Group 1 (n = 6): OA diet;
• Group 2 (n = 6): OB diet;
• Group 3 (n = 6): C diet

• Carotenoid
• Content

• Crossover RCT;
• 24;
• Brazil;
• Nonsmoking, healthy subjects (20 y–55 y)

• 400 ml red grape juices;
• Fasting blood

• Group 1 (n = 8): organic red grape juice;
• Group 2 (n = 8): conventional red grape juice;
• Group 3 (n = 8): water

• Nonrandomized self-controlled interventional trials;
• 2;
• Switzerland;
• Adults (46 y–49 y)

• Not explicitly stated;
• Urine

• Cross-sectional study;
• 196;
• Denmark;
• Adult healthy men (mean age 33 y)

• Not explicitly stated;
• Sperm

• Group 1 (n = 55): members of 2 associations promoting the development of organic agriculture;
• Group 2 (n = 141): men working in an airline company

• Cross-sectional study;
• 256;
• Denmark;
• Male farmers (mean age 38 y)

• Fruit, vegetables meat, milk, and bread;
• Sperm

• Group N (n = 166): organic intake = 0%;
• Group M (n = 39): organic intake = 1%–49%;
• Group H (n = 46): organic intake = 50%–100%

• Prospective observational cohort study;
• 68 946;
• France;
• Adults (mean age 44.2 y)

• 16 labeled organic products b ;
• NS

• Cohort study;
• 300;
• France;
• Adults (mean age 58 y)

• 264 food and beverage items;
• Urine

• Group 1 (n = 150): low organic food consumers;
• Group 2 (n = 150): high organic food consumers

• Prospective pregnancy cohort study;
• 35 107;
• Norway;
• Pregnant women who delivered a singleton male infant

• Group 1 (n = 17 996): never/seldom consume organic food;
• Group 2 (n = 17 111): sometimes, often, or mostly consume organic food

• Prospective pregnancy cohort study;
• 28 192;
• Norway;
• Nulliparous pregnant females (mean age 28 y)

• 6 food groups: milk and dairy products, bread and cereal products, eggs, vegetables, fruit, and meat;
• NS

• Group low (n = 25 699): never/seldom consume organic food;
• Group high (n = 2493): sometimes/often/mostly consume organic food

• Retrospective case–control study;
• 612;
• Denmark;
• Mothers of boys

• Milk, other dairy products, eggs, meat, fruit, and vegetables;
• NS

• Group 1 (n = 306): mothers of boys operated on for hypospadias;
• Group 2 (n = 306): matching control group

• Prospective birth cohort study;
• 312;
• Netherlands;
• Breastfeeding mothers (mean age 33 y)

• Dairy and meat products;
• Breast milk samples collected 1 mo postpartum

• Group 1 (n = 186): conventional,
• Group 2 (n = 33): 50%–90% organic food consumption;
• Group 3 (n = 37): 90% organic food consumption

• Prospective birth cohort study;
• 310;
• Netherlands;
• Breastfeeding mothers (mean age 33 y)

• Meat and dairy products;
• Breast milk samples collected 1 mo postpartum

• Group 1 (n = 185): conventional,
• Group 2 (n = 33): 50%–90% MDOO;
• Group 3 (n = 37): >90% MDOO

• Prospective observational cohort study;
• 1505;
• France;
• Infants (fetal period to 24 mo)

• Not explicitly stated;
• Urine of mothers

• Group 1 (n = 910): at least 1 otitis media (OM) episode;
• Group 2 (n = 408): at least 3 OM episodes

• Prospective birth cohort study;
• 2598;
• Netherlands;
• Children (mean age 2 y)

• Meat, eggs, vegetables, fruit, dairy products, bread, and/or dry products;
• Blood

• Group 1 (n = 2306): conventional diet (score below 21.0)
• Group 2 (n = 283): moderately organic food diet (score between 21.0 and 71.0);
• Group 3 (n = 175): strictly organic food diet (score above 71.0)

• Prospective observational cohort study;
• 62 224;
• France;
• Adults (mean age 45 y)

• 16 labeled organic products;
• NS

• Prospective cohort;
• 623 080;
• United Kingdom;
• Adult women (mean age 59 y)

• Not explicitly stated;
• NS

• Group 1 (n = 187 451): never consume organic food;
• Group 2 (n = 390 040): sometimes consumes organic food;
• Group 3 (n = 45 589): usually/always consume organic food

• Prospective observational cohort study;
• 8174;
• France;
• Adults (mean age 45 y)

• 16 labeled organic products;
• Blood

• Cross-sectional study;
• 41;
• United States;
• Breastfeeding healthy women 1 mo–3 mo postpartum (mean age was 26.8 y)

• Not explicitly stated;
• Urine and breast milk

• Group 1 (n = 17): organic dietary pattern;
• Group 2 (n = 23): conventional dietary pattern;

• Nonrandomized self-controlled interventional trials;
• 40;
• United States;
• Children (3 y–6 y)

• Fruits, bread, cereals, vegetables, dairy, eggs, juices, and snack foods;
• Urine

• Cross-sectional study;
• 240;
• United States;
• Adults with subclinical cardiovascular disease (45 y–84 y)

• Fruit and vegetables were specifically asked in questionnaires;
• Urine

• Group 1 (n = 80): “rarely or never” consume organic produce;
• Group 2 (n = 80): “sometimes” consume organic produce;
• Group 3 (n = 80): “often or always” consume organic produce

• Cross-sectional study;
• 39;
• United States;
• Children (2 y–5 y)

• Juice, fresh fruit, and vegetables;
• Urine

• Group 1 (n = 18): organic;
• Group 2 (n = 21): conventional;

• Single-blinded, crossover RCT;
• 13;
• Australia;
• Nonsmoking adults (18 y–65 y)

• Not explicitly stated;
• Urine

• Prospective observational cohort study;
• 300;
• France;
• Adults (mean age 58 y)

• 16 labeled organic products;
• Fasting blood

• Group 1 (n = 150): Nonorganic group (
• Group 2 (n = 150): Organic group (>50% of organic food in diet)

• Cross-sectional analysis;
• 2803;
• Switzerland
• Pregnant women

• Meat; eggs; vegetables; fruit; milk and milk products; bread; and dried foods (dried legumes and cereals);
• NS

• Group 1 (n = 2,766): women without GDM;
• Group 2 (n = 37): women with GDM;

• Randomized crossover interventional trial;
• 27;
• England;
• Healthy adults (21 y–36 y)

• Fruit, vegetables, and cereal products;
• Urine and blood

• Conventional group (n = 14): conventional MedDiet;
• Intervention group (n = 13): organic MedDiet

• Cluster-randomized crossover trial;
• 149;
• Cyprus;
• Children (11 y–12 y)

• Not explicitly stated;
• Urine

• Group 1 (n = 43): organic diet followed by conventional diet;
• Group 2 (n = 106): conventional diet followed by an organic diet

• Cross-sectional analysis;
• 3815;
• United States;
• Older adults (64.3 y ± .3 y)

• Milk, eggs, meat, fruit, vegetables, bread or cereals, frozen prepared meals, or other (specify);
• Blood

• Group 1 (n = 1,981): OF consumption (no);
• Group 2 (n = 1,738): OF consumption (yes)

• Crossover RCT;
• 19;
• Spain;
• Healthy people (18 y–40 y)

• Not explicitly stated;
• Blood and Urine

• Group 1 (n = 11): organic food diet followed by conventional diet;
• Group 2 (n = 8): conventional food diet followed by organic diet.

• Double-blind RCT;
• 13;
• Brazil;
• Adults with dyslipidemia (20 y–59 y)

• Juice made from BLS;
• Blood

• Group 1 (n = 5): placebo
• Group 2 (n = 6): BLS juice (low dose);
• Group 3 (n = 2): BLS juice (low dose).

• Long-term randomized interventional trial;
• 20;
• Idaho;
• Healthy pregnant women in early pregnancy (18 y–35 y)

• Fruits and vegetables;
• Urine

• Group 1 (n = 10): organic produce;
• Group 2 (n = 10): conventional produce

• Nonrandomized interventional trial;
• 103;
• Japan;
• (

• Not explicitly stated;
• Urine

• Group 1 (n = 36): organic diet for 5 d;
• Group 2 (n = 4): organic diet for 30 d;
• Group 3 (n = 63): conventional diet

• Cohort study;
• 271;
• United States;
• Senior men (mean age 53.3 y ± 17.6 y)

• Not mentioned;
• NS

• Nonrandomized self-controlled interventional trials;
• 16 participants from 4 families;
• United States;
• 7 adults (36 y–52 y) and 9 children (4 y–15 y)

• All beverages except water, all food categories, and oils, condiments, and spices (organic phase);
• Urine

• Nonrandomized self-controlled interventional trials;
• 16 participants from 4 families;
• United States;
• 7 adults (36 y–52 y) and 9 children (4 y–15 y)

• All beverages except water, all food categories, and oils, condiments, and spices (organic phase);
• Urine

• Cross-sectional analysis;
• 1775 children and 2121 adults;
• France

• A single-blind crossover randomized trial;
• 20;
• United States;
• Healthy lacto-ovo-vegetarian adults (age 38 y ± 3 y)

• Organic eggs;
• Blood

• Cohort study;
• 8081;
• France;
• Infants (age 2 mo–5.5 y)

• Not mentioned;
• NS

• Group 1 (n = 3162): infrequent CCF/infrequent OFs;
• Group 2 (n = 1314): infrequent CCF/frequent OFs;
• Group 3 (n = 2631): frequent CCF/infrequent OFs;
• Group 4 (n = 963): frequent CCF/frequent OFs

• Crossover trial;
• 23;
• United States;
• Children (3 y–11 y)

• Not mentioned;
• Urine

• Randomized crossover interventional trial;
• 27;
• England;
• Healthy adults (21 y–36 y)

• Fruit, vegetables, and cereal products;
• Urine and blood

• Conventional group (n = 14): conventional MedDiet;
• Intervention group (n = 13): organic MedDiet

• Cluster-randomized crossover trial;
• 149;
• Cyprus;
• Children (11 y–12 y)

• Not mentioned;
• Urine

• Group 1 (n = 43): organic diet followed by conventional diet;
• Group 2 (n = 106): conventional diet followed by an organic diet

Whether there were statistically significant differences in outcomes before and after organic food intervention (or between the organic food group and the conventional food group): correlation between organic food and positive outcomes is indicated by “+”, and correlation between organic food and negative outcomes is indicated by “–”; “0” indicates that there were no statistically significant differences between groups.

Sixteen categories of labeled organic products: fruits; vegetables; soy-based products; dairy products; meat and fish; eggs; grains and legumes; bread and cereals; flour; vegetable oils and condiments; ready-to-eat meals; coffee, tea, and herbal tea; wine; biscuits, chocolate, sugar, and marmalade; other foods; and dietary supplements.

Specific criteria for grouping: (1) conventional (ie, 50% of both the meat and dairy they consumed was of organic origin, or they ate no meat and 50% of the dairy they consumed was of organic origin, or they ate no dairy and 50% of the meat they consumed was of organic origin); (2) 50%–90% organic (ie, 50% of both the meat and dairy they consumed was of organic origin, but 90% of either meat or dairy was of organic origin, or they ate no meat and 50%–90% of the dairy they used was of organic origin, or they ate no dairy and 50%–90% of the meat they consumed was of organic origin); (3) 90% organic (ie, 90% of both the meat and dairy they consumed was of organic origin, or they ate no meat and 90% of the dairy they consumed was of organic origin, or they ate no dairy and 90% of the meat they consumed was of organic origin); (4) other (including any combination of 50% meat of organic origin and 50% dairy of organic origin or vice versa, and missing and inconsistent data). Abbreviations: BLS, beet leaves and stalks; BMI, body mass index; C, conventional agricultural system; CCF, commercial complementary food; CKD, chronic kidney disease; Cu, copper; ED, erectile dysfunction; GDM, gestational diabetes; HDL, high-density lipoprotein; IFN, interferon; IgE, immunoglobulin E; IL, interleukin; LDL, low-density lipoprotein; MDA, malondialdehyde; MDOO, meat and dairy products of organic origin; MedDiet, Mediterranean diet; MetS, metabolic syndrome; mo, month(s); NS, not stated; OA, organic agricultural system using animal manure; OB, organic agricultural system using cover crops; OM, otitis media; OP, organophosphate; OR, odds ratio; Org-FFQ, organic FFQ; OS, organic food score; Pb, lead; RR, relative risk; WBC, white blood cell; %Df, a decreasing detection frequency; 2,4,5-T, 2,4,5-Trichlorophenoxy acetic acid; 2,4-D, 2,4-Dichlorophenoxyacetic acid; 2-AAS, 2-aminoadipic semialdehyde; 3M-4NP, 3-Methyl-4-nitrophenol; 3-PBA, 3-phenoxybenzoic acid; 4-F-3-PBA, 4-fluoro-3-phenoxybenzoic acid; 4NP, Amino-methyl-phosphoric acid; 5OH-Imd, 5-Hydroxy-Imidacloprid; 5OH-TBZ, 5-Hydroxy-Thiabendazole; 6-CNA, 6-Chloronicotinic acid; 8-OHdG, 8-hydroxy-20-deoxyguanosine; ACE, acetamiprid; AMPA, aminomethylphosphonic acid; AOA, total antioxidant activity; BMI z-scores, age-and sex-standardized BMI z-scores; Br2CA, cis-3-(2,2-dibromovinyl)-2,2-dimethylcyclopropane carboxylic acid; CAT, catalase; CCC, Chlormequat; Cd, cadmium; cDCCA, cis-2,2-(Dichloro)-2-dimethyl vinyl cyclopropane carboxylic acid; Cl2CA, cis-/trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid; CLA, conjugated linoleic acid isomers; CLO, clothianidin; CMHC, 3-chloro-4-methyl-7-hydroxycoumarin; CPMO, Chlorpyrifos-methyl-oxon; CPO, Chlorpyrifos-oxon; CRP, C-reactive protein; CysC, cystatin C; DAPs, dialkylphosphates; DEAMP, 2-(diethylamino)-6-methylpyrimidin-4-ol/one; DEAMPY, 2-diethylamino-6-methylpyrimidin-4-ol; DEDTP, diethyldithiophosphate; DEP, diethylphosphate; DETP, diethylthiophosphate; DIN, dinotefuran; dm-ACE, N-dm_acetamiprid; DMDTP, dimethyldithiophosphate; DMP, dimethylphosphate; Eps, diethylphosphates; FFQ, Food frquency questionnaire; F-PBA, 4-fluoro-3-phenoxybenzoic acid; GLY, N-(phosphonomethyl)glycine; GPx, glutathione peroxidase; GR, glutathione reductase; GSH, reduced glutathione; GSH-Px, glutathione peroxidase; IMI, imidacloprid; IMPY, 2-isopropyl-6-methyl-pyrimidin-4-ol; m-PBA, 3-Phenoxybenzoic acid; NIT, nitenpyram; ORAC, oxygen radical absorbance capacity; PABA, p-amino benzoic acid; PBMC, peripheral blood mononuclear cells; PNP, para-nitrophenol; SOD, superoxide dismutase; TAC, total antioxidant capacity; TAG, triglyceride; t-CDCA, trans-Chrysanthemumdicarboxylic acid; TCHP, 3,5,6-Trichloro-6-hydroxypyridine; TCP, thiacloprid; TCPY, 3,5,6-trichloro-2-pyridinol; tDCCA, trans-2,2-(Dichloro)-2-dimethyl vinyl cyclopropane carboxylic acid; TEAC, Trolox equivalent antioxidative capacity; tHcy, total plasma homocysteine; TNF, tumor necrosis factor; total DEs, total DEs = DEP+ DETP + DEDTP; total DMs, total DEs = DMP+ DMTP + DMDTP; TTCA, 2-Thio thiazolidin-4-carboxylic acid; TVA, trans-vaccenic acid; UPRE, urinary pesticide residue excretion; FRAP, ferric-reducing ability of plasma; ORAC, oxygen radical absorbance capacity; CAT, catalase; GSH-Px, glutathione peroxidase; eSOD, erythrocytesuperoxide dismutase; eCAT, erythrocyte catalase; eTBARS, erythrocyte thiobarbituric acid reactive substances; PBMC, peripheral blood mononuclear cells

Main characteristics of studies examining the health effects of organic food on humans

• Parallel single-blind RCT;
• 20;
• France;
• Healthy nonsmoking females (21 y–39 y)

• Tomato puree;
• Blood

• Group 1: organic tomato puree;
• Group 2: conventional tomato puree

• Parallel double-blind RCT;
• 36;
• Germany;
• Healthy males (19 y–54 y)

• Blanched carrots;
• Blood

• Group 1: organic carrots;
• Group 2: conventional carrots;
• Group 3: followed the carotenoid-restricted diet

• Crossover double-blind RCT;
• 43;
• Germany;
• Nonsmoking healthy men (22 y–40 y)

• Apple;
• Blood

• Group 1 (n = 16): organic apples
• Group 2 (n = 16): conventional apples
• Group 3 (n = 11): maintained an apple- and polyphenol-restricted diet

• Double-blinded, crossover RCT;
• 6;
• Germany;
• Nonsmoking healthy men (23 y–32 y)

• Apple;
• Blood

• Group 1: organic apples
• Group 2: conventional apples

• Double-blinded, crossover RCT;
• 16;
• Denmark;
• Healthy adults (21 y–35 y)

• 4 different menus including common vegetables, fruits, grains, a few eggs, and meat;
• Blood and urine

• Group 1: organic diets followed by conventional diets;
• Group 2: conventional diets followed by organic diets

• Nonrandomized self-controlled interventional trials;
• 8;
• Turkey;
• Healthy non-smokers (24 y–45 y)

• Wine;
• Blood

• Nonrandomized self-controlled interventional trials;
• 23;
• United States;
• Children (3 y–11 y)

• Fruits, vegetables, and grains;
• Urine

• Nonrandomized self-controlled interventional trials;
• 23;
• United States;
• Children (3 y–11 y)

• Fresh fruits and vegetables, juices, processed fruits or vegetables, and some wheat- or corn-based items;
• Urine and saliva

• Nonrandomized self-controlled interventional trials;
• 10;
• Italy;
• Healthy nonsmoking men (30 y–65 y)

• Fruits, vegetables, red wine, and milk;
• Blood

• Cross-interventional trial;
• 150;
• Italy;
• Healthy nonsmokers (30 y–65 y) and CKD patients (42 y–54 y)

• Organic vegetables and fruits; Italian Mediterranean Diet was used;
• Fasting blood and urine

• Group 1 (n = 100): healthy subjects;
• Group 2 (n = 50): CKD patients

• Double-blinded, cross-over RCT;
• 18;
• Denmark;
• Healthy, nonsmoking, adult men (18 y–40 y)

• Crop foods, including fava beans, potatoes, rape seeds, and wheat;
• Fasting blood

• Group 1 (n = 6): OA diet;
• Group 2 (n = 6): OB diet;
• Group 3 (n = 6): C diet

• Carotenoid
• Content

• Crossover RCT;
• 24;
• Brazil;
• Nonsmoking, healthy subjects (20 y–55 y)

• 400 ml red grape juices;
• Fasting blood

• Group 1 (n = 8): organic red grape juice;
• Group 2 (n = 8): conventional red grape juice;
• Group 3 (n = 8): water

• Nonrandomized self-controlled interventional trials;
• 2;
• Switzerland;
• Adults (46 y–49 y)

• Not explicitly stated;
• Urine

• Cross-sectional study;
• 196;
• Denmark;
• Adult healthy men (mean age 33 y)

• Not explicitly stated;
• Sperm

• Group 1 (n = 55): members of 2 associations promoting the development of organic agriculture;
• Group 2 (n = 141): men working in an airline company

• Cross-sectional study;
• 256;
• Denmark;
• Male farmers (mean age 38 y)

• Fruit, vegetables meat, milk, and bread;
• Sperm

• Group N (n = 166): organic intake = 0%;
• Group M (n = 39): organic intake = 1%–49%;
• Group H (n = 46): organic intake = 50%–100%

• Prospective observational cohort study;
• 68 946;
• France;
• Adults (mean age 44.2 y)

• 16 labeled organic products b ;
• NS

• Cohort study;
• 300;
• France;
• Adults (mean age 58 y)

• 264 food and beverage items;
• Urine

• Group 1 (n = 150): low organic food consumers;
• Group 2 (n = 150): high organic food consumers

• Prospective pregnancy cohort study;
• 35 107;
• Norway;
• Pregnant women who delivered a singleton male infant

• Group 1 (n = 17 996): never/seldom consume organic food;
• Group 2 (n = 17 111): sometimes, often, or mostly consume organic food

• Prospective pregnancy cohort study;
• 28 192;
• Norway;
• Nulliparous pregnant females (mean age 28 y)

• 6 food groups: milk and dairy products, bread and cereal products, eggs, vegetables, fruit, and meat;
• NS

• Group low (n = 25 699): never/seldom consume organic food;
• Group high (n = 2493): sometimes/often/mostly consume organic food

• Retrospective case–control study;
• 612;
• Denmark;
• Mothers of boys

• Milk, other dairy products, eggs, meat, fruit, and vegetables;
• NS

• Group 1 (n = 306): mothers of boys operated on for hypospadias;
• Group 2 (n = 306): matching control group

• Prospective birth cohort study;
• 312;
• Netherlands;
• Breastfeeding mothers (mean age 33 y)

• Dairy and meat products;
• Breast milk samples collected 1 mo postpartum

• Group 1 (n = 186): conventional,
• Group 2 (n = 33): 50%–90% organic food consumption;
• Group 3 (n = 37): 90% organic food consumption

• Prospective birth cohort study;
• 310;
• Netherlands;
• Breastfeeding mothers (mean age 33 y)

• Meat and dairy products;
• Breast milk samples collected 1 mo postpartum

• Group 1 (n = 185): conventional,
• Group 2 (n = 33): 50%–90% MDOO;
• Group 3 (n = 37): >90% MDOO

• Prospective observational cohort study;
• 1505;
• France;
• Infants (fetal period to 24 mo)

• Not explicitly stated;
• Urine of mothers

• Group 1 (n = 910): at least 1 otitis media (OM) episode;
• Group 2 (n = 408): at least 3 OM episodes

• Prospective birth cohort study;
• 2598;
• Netherlands;
• Children (mean age 2 y)

• Meat, eggs, vegetables, fruit, dairy products, bread, and/or dry products;
• Blood

• Group 1 (n = 2306): conventional diet (score below 21.0)
• Group 2 (n = 283): moderately organic food diet (score between 21.0 and 71.0);
• Group 3 (n = 175): strictly organic food diet (score above 71.0)

• Prospective observational cohort study;
• 62 224;
• France;
• Adults (mean age 45 y)

• 16 labeled organic products;
• NS

• Prospective cohort;
• 623 080;
• United Kingdom;
• Adult women (mean age 59 y)

• Not explicitly stated;
• NS

• Group 1 (n = 187 451): never consume organic food;
• Group 2 (n = 390 040): sometimes consumes organic food;
• Group 3 (n = 45 589): usually/always consume organic food

• Prospective observational cohort study;
• 8174;
• France;
• Adults (mean age 45 y)

• 16 labeled organic products;
• Blood

• Cross-sectional study;
• 41;
• United States;
• Breastfeeding healthy women 1 mo–3 mo postpartum (mean age was 26.8 y)

• Not explicitly stated;
• Urine and breast milk

• Group 1 (n = 17): organic dietary pattern;
• Group 2 (n = 23): conventional dietary pattern;

• Nonrandomized self-controlled interventional trials;
• 40;
• United States;
• Children (3 y–6 y)

• Fruits, bread, cereals, vegetables, dairy, eggs, juices, and snack foods;
• Urine

• Cross-sectional study;
• 240;
• United States;
• Adults with subclinical cardiovascular disease (45 y–84 y)

• Fruit and vegetables were specifically asked in questionnaires;
• Urine

• Group 1 (n = 80): “rarely or never” consume organic produce;
• Group 2 (n = 80): “sometimes” consume organic produce;
• Group 3 (n = 80): “often or always” consume organic produce

• Cross-sectional study;
• 39;
• United States;
• Children (2 y–5 y)

• Juice, fresh fruit, and vegetables;
• Urine

• Group 1 (n = 18): organic;
• Group 2 (n = 21): conventional;

• Single-blinded, crossover RCT;
• 13;
• Australia;
• Nonsmoking adults (18 y–65 y)

• Not explicitly stated;
• Urine

• Prospective observational cohort study;
• 300;
• France;
• Adults (mean age 58 y)

• 16 labeled organic products;
• Fasting blood

• Group 1 (n = 150): Nonorganic group (
• Group 2 (n = 150): Organic group (>50% of organic food in diet)

• Cross-sectional analysis;
• 2803;
• Switzerland
• Pregnant women

• Meat; eggs; vegetables; fruit; milk and milk products; bread; and dried foods (dried legumes and cereals);
• NS

• Group 1 (n = 2,766): women without GDM;
• Group 2 (n = 37): women with GDM;

• Randomized crossover interventional trial;
• 27;
• England;
• Healthy adults (21 y–36 y)

• Fruit, vegetables, and cereal products;
• Urine and blood

• Conventional group (n = 14): conventional MedDiet;
• Intervention group (n = 13): organic MedDiet

• Cluster-randomized crossover trial;
• 149;
• Cyprus;
• Children (11 y–12 y)

• Not explicitly stated;
• Urine

• Group 1 (n = 43): organic diet followed by conventional diet;
• Group 2 (n = 106): conventional diet followed by an organic diet

• Cross-sectional analysis;
• 3815;
• United States;
• Older adults (64.3 y ± .3 y)

• Milk, eggs, meat, fruit, vegetables, bread or cereals, frozen prepared meals, or other (specify);
• Blood

• Group 1 (n = 1,981): OF consumption (no);
• Group 2 (n = 1,738): OF consumption (yes)

• Crossover RCT;
• 19;
• Spain;
• Healthy people (18 y–40 y)

• Not explicitly stated;
• Blood and Urine

• Group 1 (n = 11): organic food diet followed by conventional diet;
• Group 2 (n = 8): conventional food diet followed by organic diet.

• Double-blind RCT;
• 13;
• Brazil;
• Adults with dyslipidemia (20 y–59 y)

• Juice made from BLS;
• Blood

• Group 1 (n = 5): placebo
• Group 2 (n = 6): BLS juice (low dose);
• Group 3 (n = 2): BLS juice (low dose).

• Long-term randomized interventional trial;
• 20;
• Idaho;
• Healthy pregnant women in early pregnancy (18 y–35 y)

• Fruits and vegetables;
• Urine

• Group 1 (n = 10): organic produce;
• Group 2 (n = 10): conventional produce

• Nonrandomized interventional trial;
• 103;
• Japan;
• (

• Not explicitly stated;
• Urine

• Group 1 (n = 36): organic diet for 5 d;
• Group 2 (n = 4): organic diet for 30 d;
• Group 3 (n = 63): conventional diet

• Cohort study;
• 271;
• United States;
• Senior men (mean age 53.3 y ± 17.6 y)

• Not mentioned;
• NS

• Nonrandomized self-controlled interventional trials;
• 16 participants from 4 families;
• United States;
• 7 adults (36 y–52 y) and 9 children (4 y–15 y)

• All beverages except water, all food categories, and oils, condiments, and spices (organic phase);
• Urine

• Nonrandomized self-controlled interventional trials;
• 16 participants from 4 families;
• United States;
• 7 adults (36 y–52 y) and 9 children (4 y–15 y)

• All beverages except water, all food categories, and oils, condiments, and spices (organic phase);
• Urine

• Cross-sectional analysis;
• 1775 children and 2121 adults;
• France

• A single-blind crossover randomized trial;
• 20;
• United States;
• Healthy lacto-ovo-vegetarian adults (age 38 y ± 3 y)

• Organic eggs;
• Blood

• Cohort study;
• 8081;
• France;
• Infants (age 2 mo–5.5 y)

• Not mentioned;
• NS

• Group 1 (n = 3162): infrequent CCF/infrequent OFs;
• Group 2 (n = 1314): infrequent CCF/frequent OFs;
• Group 3 (n = 2631): frequent CCF/infrequent OFs;
• Group 4 (n = 963): frequent CCF/frequent OFs

• Crossover trial;
• 23;
• United States;
• Children (3 y–11 y)

• Not mentioned;
• Urine

• Randomized crossover interventional trial;
• 27;
• England;
• Healthy adults (21 y–36 y)

• Fruit, vegetables, and cereal products;
• Urine and blood

• Conventional group (n = 14): conventional MedDiet;
• Intervention group (n = 13): organic MedDiet

• Cluster-randomized crossover trial;
• 149;
• Cyprus;
• Children (11 y–12 y)

• Not mentioned;
• Urine

• Group 1 (n = 43): organic diet followed by conventional diet;
• Group 2 (n = 106): conventional diet followed by an organic diet

• Parallel single-blind RCT;
• 20;
• France;
• Healthy nonsmoking females (21 y–39 y)

• Tomato puree;
• Blood

• Group 1: organic tomato puree;
• Group 2: conventional tomato puree

• Parallel double-blind RCT;
• 36;
• Germany;
• Healthy males (19 y–54 y)

• Blanched carrots;
• Blood

• Group 1: organic carrots;
• Group 2: conventional carrots;
• Group 3: followed the carotenoid-restricted diet

• Crossover double-blind RCT;
• 43;
• Germany;
• Nonsmoking healthy men (22 y–40 y)

• Apple;
• Blood

• Group 1 (n = 16): organic apples
• Group 2 (n = 16): conventional apples
• Group 3 (n = 11): maintained an apple- and polyphenol-restricted diet

• Double-blinded, crossover RCT;
• 6;
• Germany;
• Nonsmoking healthy men (23 y–32 y)

• Apple;
• Blood

• Group 1: organic apples
• Group 2: conventional apples

• Double-blinded, crossover RCT;
• 16;
• Denmark;
• Healthy adults (21 y–35 y)

• 4 different menus including common vegetables, fruits, grains, a few eggs, and meat;
• Blood and urine

• Group 1: organic diets followed by conventional diets;
• Group 2: conventional diets followed by organic diets

• Nonrandomized self-controlled interventional trials;
• 8;
• Turkey;
• Healthy non-smokers (24 y–45 y)

• Wine;
• Blood

• Nonrandomized self-controlled interventional trials;
• 23;
• United States;
• Children (3 y–11 y)

• Fruits, vegetables, and grains;
• Urine

• Nonrandomized self-controlled interventional trials;
• 23;
• United States;
• Children (3 y–11 y)

• Fresh fruits and vegetables, juices, processed fruits or vegetables, and some wheat- or corn-based items;
• Urine and saliva

• Nonrandomized self-controlled interventional trials;
• 10;
• Italy;
• Healthy nonsmoking men (30 y–65 y)

• Fruits, vegetables, red wine, and milk;
• Blood

• Cross-interventional trial;
• 150;
• Italy;
• Healthy nonsmokers (30 y–65 y) and CKD patients (42 y–54 y)

• Organic vegetables and fruits; Italian Mediterranean Diet was used;
• Fasting blood and urine

• Group 1 (n = 100): healthy subjects;
• Group 2 (n = 50): CKD patients

• Double-blinded, cross-over RCT;
• 18;
• Denmark;
• Healthy, nonsmoking, adult men (18 y–40 y)

• Crop foods, including fava beans, potatoes, rape seeds, and wheat;
• Fasting blood

• Group 1 (n = 6): OA diet;
• Group 2 (n = 6): OB diet;
• Group 3 (n = 6): C diet

• Carotenoid
• Content

• Crossover RCT;
• 24;
• Brazil;
• Nonsmoking, healthy subjects (20 y–55 y)

• 400 ml red grape juices;
• Fasting blood

• Group 1 (n = 8): organic red grape juice;
• Group 2 (n = 8): conventional red grape juice;
• Group 3 (n = 8): water

• Nonrandomized self-controlled interventional trials;
• 2;
• Switzerland;
• Adults (46 y–49 y)

• Not explicitly stated;
• Urine

• Cross-sectional study;
• 196;
• Denmark;
• Adult healthy men (mean age 33 y)

• Not explicitly stated;
• Sperm

• Group 1 (n = 55): members of 2 associations promoting the development of organic agriculture;
• Group 2 (n = 141): men working in an airline company

• Cross-sectional study;
• 256;
• Denmark;
• Male farmers (mean age 38 y)

• Fruit, vegetables meat, milk, and bread;
• Sperm

• Group N (n = 166): organic intake = 0%;
• Group M (n = 39): organic intake = 1%–49%;
• Group H (n = 46): organic intake = 50%–100%

• Prospective observational cohort study;
• 68 946;
• France;
• Adults (mean age 44.2 y)

• 16 labeled organic products b ;
• NS

• Cohort study;
• 300;
• France;
• Adults (mean age 58 y)

• 264 food and beverage items;
• Urine

• Group 1 (n = 150): low organic food consumers;
• Group 2 (n = 150): high organic food consumers

• Prospective pregnancy cohort study;
• 35 107;
• Norway;
• Pregnant women who delivered a singleton male infant

• Group 1 (n = 17 996): never/seldom consume organic food;
• Group 2 (n = 17 111): sometimes, often, or mostly consume organic food

• Prospective pregnancy cohort study;
• 28 192;
• Norway;
• Nulliparous pregnant females (mean age 28 y)

• 6 food groups: milk and dairy products, bread and cereal products, eggs, vegetables, fruit, and meat;
• NS

• Group low (n = 25 699): never/seldom consume organic food;
• Group high (n = 2493): sometimes/often/mostly consume organic food

• Retrospective case–control study;
• 612;
• Denmark;
• Mothers of boys

• Milk, other dairy products, eggs, meat, fruit, and vegetables;
• NS

• Group 1 (n = 306): mothers of boys operated on for hypospadias;
• Group 2 (n = 306): matching control group

• Prospective birth cohort study;
• 312;
• Netherlands;
• Breastfeeding mothers (mean age 33 y)

• Dairy and meat products;
• Breast milk samples collected 1 mo postpartum

• Group 1 (n = 186): conventional,
• Group 2 (n = 33): 50%–90% organic food consumption;
• Group 3 (n = 37): 90% organic food consumption

• Prospective birth cohort study;
• 310;
• Netherlands;
• Breastfeeding mothers (mean age 33 y)

• Meat and dairy products;
• Breast milk samples collected 1 mo postpartum

• Group 1 (n = 185): conventional,
• Group 2 (n = 33): 50%–90% MDOO;
• Group 3 (n = 37): >90% MDOO

• Prospective observational cohort study;
• 1505;
• France;
• Infants (fetal period to 24 mo)

• Not explicitly stated;
• Urine of mothers

• Group 1 (n = 910): at least 1 otitis media (OM) episode;
• Group 2 (n = 408): at least 3 OM episodes

• Prospective birth cohort study;
• 2598;
• Netherlands;
• Children (mean age 2 y)

• Meat, eggs, vegetables, fruit, dairy products, bread, and/or dry products;
• Blood

• Group 1 (n = 2306): conventional diet (score below 21.0)
• Group 2 (n = 283): moderately organic food diet (score between 21.0 and 71.0);
• Group 3 (n = 175): strictly organic food diet (score above 71.0)

• Prospective observational cohort study;
• 62 224;
• France;
• Adults (mean age 45 y)

• 16 labeled organic products;
• NS

• Prospective cohort;
• 623 080;
• United Kingdom;
• Adult women (mean age 59 y)

• Not explicitly stated;
• NS

• Group 1 (n = 187 451): never consume organic food;
• Group 2 (n = 390 040): sometimes consumes organic food;
• Group 3 (n = 45 589): usually/always consume organic food

• Prospective observational cohort study;
• 8174;
• France;
• Adults (mean age 45 y)

• 16 labeled organic products;
• Blood

• Cross-sectional study;
• 41;
• United States;
• Breastfeeding healthy women 1 mo–3 mo postpartum (mean age was 26.8 y)

• Not explicitly stated;
• Urine and breast milk

• Group 1 (n = 17): organic dietary pattern;
• Group 2 (n = 23): conventional dietary pattern;

• Nonrandomized self-controlled interventional trials;
• 40;
• United States;
• Children (3 y–6 y)

• Fruits, bread, cereals, vegetables, dairy, eggs, juices, and snack foods;
• Urine

• Cross-sectional study;
• 240;
• United States;
• Adults with subclinical cardiovascular disease (45 y–84 y)

• Fruit and vegetables were specifically asked in questionnaires;
• Urine

• Group 1 (n = 80): “rarely or never” consume organic produce;
• Group 2 (n = 80): “sometimes” consume organic produce;
• Group 3 (n = 80): “often or always” consume organic produce

• Cross-sectional study;
• 39;
• United States;
• Children (2 y–5 y)

• Juice, fresh fruit, and vegetables;
• Urine

• Group 1 (n = 18): organic;
• Group 2 (n = 21): conventional;

• Single-blinded, crossover RCT;
• 13;
• Australia;
• Nonsmoking adults (18 y–65 y)

• Not explicitly stated;
• Urine

• Prospective observational cohort study;
• 300;
• France;
• Adults (mean age 58 y)

• 16 labeled organic products;
• Fasting blood

• Group 1 (n = 150): Nonorganic group (
• Group 2 (n = 150): Organic group (>50% of organic food in diet)

• Cross-sectional analysis;
• 2803;
• Switzerland
• Pregnant women

• Meat; eggs; vegetables; fruit; milk and milk products; bread; and dried foods (dried legumes and cereals);
• NS

• Group 1 (n = 2,766): women without GDM;
• Group 2 (n = 37): women with GDM;

• Randomized crossover interventional trial;
• 27;
• England;
• Healthy adults (21 y–36 y)

• Fruit, vegetables, and cereal products;
• Urine and blood

• Conventional group (n = 14): conventional MedDiet;
• Intervention group (n = 13): organic MedDiet

• Cluster-randomized crossover trial;
• 149;
• Cyprus;
• Children (11 y–12 y)

• Not explicitly stated;
• Urine

• Group 1 (n = 43): organic diet followed by conventional diet;
• Group 2 (n = 106): conventional diet followed by an organic diet

• Cross-sectional analysis;
• 3815;
• United States;
• Older adults (64.3 y ± .3 y)

• Milk, eggs, meat, fruit, vegetables, bread or cereals, frozen prepared meals, or other (specify);
• Blood

• Group 1 (n = 1,981): OF consumption (no);
• Group 2 (n = 1,738): OF consumption (yes)

• Crossover RCT;
• 19;
• Spain;
• Healthy people (18 y–40 y)

• Not explicitly stated;
• Blood and Urine

• Group 1 (n = 11): organic food diet followed by conventional diet;
• Group 2 (n = 8): conventional food diet followed by organic diet.

• Double-blind RCT;
• 13;
• Brazil;
• Adults with dyslipidemia (20 y–59 y)

• Juice made from BLS;
• Blood

• Group 1 (n = 5): placebo
• Group 2 (n = 6): BLS juice (low dose);
• Group 3 (n = 2): BLS juice (low dose).

• Long-term randomized interventional trial;
• 20;
• Idaho;
• Healthy pregnant women in early pregnancy (18 y–35 y)

• Fruits and vegetables;
• Urine

• Group 1 (n = 10): organic produce;
• Group 2 (n = 10): conventional produce

• Nonrandomized interventional trial;
• 103;
• Japan;
• (

• Not explicitly stated;
• Urine

• Group 1 (n = 36): organic diet for 5 d;
• Group 2 (n = 4): organic diet for 30 d;
• Group 3 (n = 63): conventional diet

• Cohort study;
• 271;
• United States;
• Senior men (mean age 53.3 y ± 17.6 y)

• Not mentioned;
• NS

• Nonrandomized self-controlled interventional trials;
• 16 participants from 4 families;
• United States;
• 7 adults (36 y–52 y) and 9 children (4 y–15 y)

• All beverages except water, all food categories, and oils, condiments, and spices (organic phase);
• Urine

• Nonrandomized self-controlled interventional trials;
• 16 participants from 4 families;
• United States;
• 7 adults (36 y–52 y) and 9 children (4 y–15 y)

• All beverages except water, all food categories, and oils, condiments, and spices (organic phase);
• Urine

• Cross-sectional analysis;
• 1775 children and 2121 adults;
• France

• A single-blind crossover randomized trial;
• 20;
• United States;
• Healthy lacto-ovo-vegetarian adults (age 38 y ± 3 y)

• Organic eggs;
• Blood

• Cohort study;
• 8081;
• France;
• Infants (age 2 mo–5.5 y)

• Not mentioned;
• NS

• Group 1 (n = 3162): infrequent CCF/infrequent OFs;
• Group 2 (n = 1314): infrequent CCF/frequent OFs;
• Group 3 (n = 2631): frequent CCF/infrequent OFs;
• Group 4 (n = 963): frequent CCF/frequent OFs

• Crossover trial;
• 23;
• United States;
• Children (3 y–11 y)

• Not mentioned;
• Urine

• Randomized crossover interventional trial;
• 27;
• England;
• Healthy adults (21 y–36 y)

• Fruit, vegetables, and cereal products;
• Urine and blood

• Conventional group (n = 14): conventional MedDiet;
• Intervention group (n = 13): organic MedDiet

• Cluster-randomized crossover trial;
• 149;
• Cyprus;
• Children (11 y–12 y)

• Not mentioned;
• Urine

• Group 1 (n = 43): organic diet followed by conventional diet;
• Group 2 (n = 106): conventional diet followed by an organic diet

Whether there were statistically significant differences in outcomes before and after organic food intervention (or between the organic food group and the conventional food group): correlation between organic food and positive outcomes is indicated by “+”, and correlation between organic food and negative outcomes is indicated by “–”; “0” indicates that there were no statistically significant differences between groups.

Sixteen categories of labeled organic products: fruits; vegetables; soy-based products; dairy products; meat and fish; eggs; grains and legumes; bread and cereals; flour; vegetable oils and condiments; ready-to-eat meals; coffee, tea, and herbal tea; wine; biscuits, chocolate, sugar, and marmalade; other foods; and dietary supplements.

Specific criteria for grouping: (1) conventional (ie, 50% of both the meat and dairy they consumed was of organic origin, or they ate no meat and 50% of the dairy they consumed was of organic origin, or they ate no dairy and 50% of the meat they consumed was of organic origin); (2) 50%–90% organic (ie, 50% of both the meat and dairy they consumed was of organic origin, but 90% of either meat or dairy was of organic origin, or they ate no meat and 50%–90% of the dairy they used was of organic origin, or they ate no dairy and 50%–90% of the meat they consumed was of organic origin); (3) 90% organic (ie, 90% of both the meat and dairy they consumed was of organic origin, or they ate no meat and 90% of the dairy they consumed was of organic origin, or they ate no dairy and 90% of the meat they consumed was of organic origin); (4) other (including any combination of 50% meat of organic origin and 50% dairy of organic origin or vice versa, and missing and inconsistent data). Abbreviations: BLS, beet leaves and stalks; BMI, body mass index; C, conventional agricultural system; CCF, commercial complementary food; CKD, chronic kidney disease; Cu, copper; ED, erectile dysfunction; GDM, gestational diabetes; HDL, high-density lipoprotein; IFN, interferon; IgE, immunoglobulin E; IL, interleukin; LDL, low-density lipoprotein; MDA, malondialdehyde; MDOO, meat and dairy products of organic origin; MedDiet, Mediterranean diet; MetS, metabolic syndrome; mo, month(s); NS, not stated; OA, organic agricultural system using animal manure; OB, organic agricultural system using cover crops; OM, otitis media; OP, organophosphate; OR, odds ratio; Org-FFQ, organic FFQ; OS, organic food score; Pb, lead; RR, relative risk; WBC, white blood cell; %Df, a decreasing detection frequency; 2,4,5-T, 2,4,5-Trichlorophenoxy acetic acid; 2,4-D, 2,4-Dichlorophenoxyacetic acid; 2-AAS, 2-aminoadipic semialdehyde; 3M-4NP, 3-Methyl-4-nitrophenol; 3-PBA, 3-phenoxybenzoic acid; 4-F-3-PBA, 4-fluoro-3-phenoxybenzoic acid; 4NP, Amino-methyl-phosphoric acid; 5OH-Imd, 5-Hydroxy-Imidacloprid; 5OH-TBZ, 5-Hydroxy-Thiabendazole; 6-CNA, 6-Chloronicotinic acid; 8-OHdG, 8-hydroxy-20-deoxyguanosine; ACE, acetamiprid; AMPA, aminomethylphosphonic acid; AOA, total antioxidant activity; BMI z-scores, age-and sex-standardized BMI z-scores; Br2CA, cis-3-(2,2-dibromovinyl)-2,2-dimethylcyclopropane carboxylic acid; CAT, catalase; CCC, Chlormequat; Cd, cadmium; cDCCA, cis-2,2-(Dichloro)-2-dimethyl vinyl cyclopropane carboxylic acid; Cl2CA, cis-/trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid; CLA, conjugated linoleic acid isomers; CLO, clothianidin; CMHC, 3-chloro-4-methyl-7-hydroxycoumarin; CPMO, Chlorpyrifos-methyl-oxon; CPO, Chlorpyrifos-oxon; CRP, C-reactive protein; CysC, cystatin C; DAPs, dialkylphosphates; DEAMP, 2-(diethylamino)-6-methylpyrimidin-4-ol/one; DEAMPY, 2-diethylamino-6-methylpyrimidin-4-ol; DEDTP, diethyldithiophosphate; DEP, diethylphosphate; DETP, diethylthiophosphate; DIN, dinotefuran; dm-ACE, N-dm_acetamiprid; DMDTP, dimethyldithiophosphate; DMP, dimethylphosphate; Eps, diethylphosphates; FFQ, Food frquency questionnaire; F-PBA, 4-fluoro-3-phenoxybenzoic acid; GLY, N-(phosphonomethyl)glycine; GPx, glutathione peroxidase; GR, glutathione reductase; GSH, reduced glutathione; GSH-Px, glutathione peroxidase; IMI, imidacloprid; IMPY, 2-isopropyl-6-methyl-pyrimidin-4-ol; m-PBA, 3-Phenoxybenzoic acid; NIT, nitenpyram; ORAC, oxygen radical absorbance capacity; PABA, p-amino benzoic acid; PBMC, peripheral blood mononuclear cells; PNP, para-nitrophenol; SOD, superoxide dismutase; TAC, total antioxidant capacity; TAG, triglyceride; t-CDCA, trans-Chrysanthemumdicarboxylic acid; TCHP, 3,5,6-Trichloro-6-hydroxypyridine; TCP, thiacloprid; TCPY, 3,5,6-trichloro-2-pyridinol; tDCCA, trans-2,2-(Dichloro)-2-dimethyl vinyl cyclopropane carboxylic acid; TEAC, Trolox equivalent antioxidative capacity; tHcy, total plasma homocysteine; TNF, tumor necrosis factor; total DEs, total DEs = DEP+ DETP + DEDTP; total DMs, total DEs = DMP+ DMTP + DMDTP; TTCA, 2-Thio thiazolidin-4-carboxylic acid; TVA, trans-vaccenic acid; UPRE, urinary pesticide residue excretion; FRAP, ferric-reducing ability of plasma; ORAC, oxygen radical absorbance capacity; CAT, catalase; GSH-Px, glutathione peroxidase; eSOD, erythrocytesuperoxide dismutase; eCAT, erythrocyte catalase; eTBARS, erythrocyte thiobarbituric acid reactive substances; PBMC, peripheral blood mononuclear cells

Summary of studies examining the relationship between organic food intake and potential health effects