Feed Composition Differences Resulting from Organic and Conventional Farming Practices Affect Physiological Parameters in Wistar Rats-Results from a Factorial, Two-Generation Dietary Intervention Trial

Potential Health Benefits of a Diet Rich in Organic Fruit and Vegetables versus a Diet Based on Conventional Produce: A Systematic Review

CONTEXT

Over the past decade, the production and consumption of organic food (OF) have received increasing interest. Scientific studies have shown better quality of organic fruit and vegetables (FV) in terms of nutrients and pesticide contents, but it appears difficult to conclude if there are potentially greater health benefits of these products compared with conventional food (CF).

OBJECTIVE

To determine whether the current scientific literature demonstrates that a diet rich in organic FV is healthier than 1 based on conventional produce.

METHODS

A systematic search was conducted using the PubMed and Web of Science databases for articles published between January 2003 and December 2022. Articles were analyzed uniformly by 2 reviewer, using a specific template summary sheet, and scored from 1 to 5. The level of evidence and the quality of studies in humans were assessed using the Jadad score and the French National Authority for Health method.

RESULTS

A total of 12 human studies were included. Studies often reported contradictory or even opposite results, with methodological limitations. Only 6 of the 12 studies found significant associations between OF and the health outcomes evaluated.

CONCLUSION

The current data do not enable a firm conclusion about a greater health benefit for a diet rich in FV based on products grown organically compared with conventional farming. There is a paucity of available data and considerable heterogeneity in study designs (participants, exposures, durations, health outcomes, and residual confounding factors). Well-designed interventional studies are required.

Effects of Agricultural Intensification on Mediterranean Diets: A Narrative Review

INTRODUCTION

Mediterranean diets (MedDiets) are linked to substantial health benefits. However, there is also growing evidence that the intensification of food production over the last 60 years has resulted in nutritionally relevant changes in the composition of foods that may augment the health benefits of MedDiets.

OBJECTIVE

To synthesize, summarize, and critically evaluate the currently available evidence for changes in food composition resulting from agricultural intensification practices and their potential impact on the health benefits of MedDiets.

METHODS

We summarized/synthesized information from (i) systematic literature reviews/meta-analyses and more recently published articles on composition differences between conventional and organic foods, (ii) desk studies which compared food composition data from before and after agricultural intensification, (iii) recent retail and farm surveys and/or factorial field experiments that identified specific agronomic practices responsible for nutritionally relevant changes in food composition, and (iv) a recent systematic literature review and a small number of subsequently published observational and dietary intervention studies that investigated the potential health impacts of changes in food composition resulting from agricultural intensification.

RESULTS AND DISCUSSION

There has been growing evidence that the intensification of food production has resulted in (i) lower concentrations of nutritionally desirable compounds (e.g., phenolics, certain vitamins, mineral micronutrients including Se, Zn, and omega-3 fatty acids, α-tocopherol) and/or (ii) higher concentrations of nutritionally undesirable or toxic compounds (pesticide residues, cadmium, omega-6 fatty acids) in many of the foods (including wholegrain cereals, fruit and vegetables, olive oil, dairy products and meat from small ruminants, and fish) that are thought to contribute to the health benefits associated with MedDiets. The evidence for negative health impacts of consuming foods from intensified conventional production systems has also increased but is still limited and based primarily on evidence from observational studies. Limitations and gaps in the current evidence base are discussed. Conclusions: There is now substantial evidence that the intensification of agricultural food production has resulted in a decline in the nutritional quality of many of the foods that are recognized to contribute to the positive health impacts associated with adhering to traditional MedDiets. Further research is needed to quantify to what extent this decline augments the positive health impacts of adhering to a traditional MedDiet.

Breeding Bread-Making Wheat Varieties for Organic Farming Systems: The Need to Target Productivity, Robustness, Resource Use Efficiency and Grain Quality Traits

Agronomic protocols (rotation, tillage, fertilization and crop protection) commonly used in organic and conventional crop production differ significantly and there is evidence that modern varieties developed for conventional high-input farming systems do not have the combination of traits required for optimum performance in organic farming systems. Specifically, there is evidence that prohibition on the use of water-soluble, mineral N, P and K fertilizers and synthetic pesticide inputs in organic farming results in a need to revise both breeding and selection protocols. For organic production systems, the focus needs to be on the following: (i) traits prioritized by organic farmers such as high nutrient use efficiency from organic fertilizer inputs, competitiveness against weeds, and pest and disease resistance, (ii) processing quality parameters defined by millers and bakers and (iii) nutritional quality parameters demanded by organic consumers. In this article, we review evidence from variety trials and factorial field experiments that (i) studied to what extent there is a need for organic farming focused breeding programs, (ii) investigated which traits/trait combinations should be targeted in these breeding programs and/or (iii) compared the performance of modern varieties developed for the conventional sector with traditional/older varieties favored by organic farmers and/or new varieties developed in organic farming focused breeding programs. Our review focuses on wheat because there have been organic and/or low-input farming focused wheat breeding programs for more than 20 years in Europe, which has allowed the performance of varieties/genotypes from organic/low-input and conventional farming focused breeding programs to be compared.

Exposures to pesticides and risk of cancer: Evaluation of recent epidemiological evidence in humans and paths forward

Knowledge of the role in cancer etiology of environmental exposures as pesticides is a prerequisite for primary prevention. We review 63 epidemiological studies on exposure to pesticides and cancer risk in humans published from 2017 to 2021, with emphasis on new findings, methodological approaches, and gaps in the existing literature. While much of the recent evidence suggests causal relationships between pesticide exposure and cancer, the strongest evidence exists for acute myeloid leukemia (AML) and colorectal cancer (CRC), diseases in which the observed associations were consistent across several studies, including high-quality prospective studies and those using biomarkers for exposure assessment, with some observing dose-response relationships. Though high-quality studies have been published since the IARC monograph on organophosphate insecticides in 2017, there are still gaps in the literature on carcinogenic evidence in humans for a large number of pesticides. To further knowledge, we suggest leveraging new techniques and methods to increase sensitivity and precision of exposure assessment, incorporate multi-omics data, and investigate more thoroughly exposure to chemical mixtures. There is also a strong need for better and larger population-based cohort studies that include younger and nonoccupationally exposed individuals, particularly during developmental periods of susceptibility. Though the existing evidence has limitations, as always in science, there is sufficient evidence to implement policies and regulatory action that limit pesticide exposure in humans and, hence, further prevent a significant burden of cancers.

Biological Activity of Extracts from Differently Produced Blueberry Fruits in Inhibiting Proliferation and Inducing Apoptosis of HT-29 Cells

For several decades, people have been searching for natural substances of plant origin that, when introduced into the diet, could strengthen immunity, have anticancer properties, and support conventional therapy. The development of agriculture with the implementation of various plant cultivation systems, apart from the economic aspect, results in the search for such cultivation conditions that would contribute to obtaining the most beneficial product for health. Therefore, the aim of our research is as follows: (a) to compare the antiproliferative activity and the ability to induce apoptosis of HT-29 cells by extracts from blueberry fruits deriving from different types of cultivation systems (conventional, organic, and biodynamic); (b) to examine whether the interaction of extracts with anticancer drugs used in the treatment of colorectal cancer is influenced by the type of cultivation, and (c) to investigate whether extracts obtained from fruits from subsequent years of cultivation retain the same biological activity. The results of our study are promising but inconclusive. A statistically significant difference occurred in only one of the two years of the study. The greatest inhibition of proliferation is observed for biodynamic cultivation compared to organic cultivation, while the highest levels of apoptosis and necrosis of HT-29 cells are induced by blueberry fruit extracts obtained from organic cultivation. The complementary effect of the extracts on the inhibition of HT-29 cell proliferation by anticancer drugs (5-FU and Erbitux) is not demonstrated. The induction of apoptosis by 5-FU is not enhanced by blueberry extracts, in contrast to necrosis. The level of apoptosis and necrosis induced by Erbitux is potentiated, but no dependence on crop type is shown. Blueberry fruit extracts from two consecutive years of cultivation did not maintain the same activity. A plausible reason for the variability in the composition and biological activity of fruit extracts obtained from two years of cultivation is the varying environmental conditions.

Diet and food type affect urinary pesticide residue excretion profiles in healthy individuals: results of a randomized controlled dietary intervention trial

BACKGROUND

Observational studies have linked pesticide exposure to various diseases, whereas organic food consumption has been associated with positive health outcomes. Organic farming standards prohibit the use of most pesticides, and organic food consumption may therefore reduce pesticide exposure.

OBJECTIVES

To determine the effects of diet (Western compared with Mediterranean) and food type (conventional compared with organic) and sex on urinary pesticide residue excretion (UPRE), as well as associations between specific diet components and UPRE.

METHODS

In this 2-wk, randomized dietary intervention trial, healthy adults were randomly allocated to an intervention (n = 13) or conventional (n = 14) group. Whereas participants in the intervention group consumed a Mediterranean diet (MedDiet) made entirely from organic foods, the conventional group consumed a MedDiet made entirely from conventional foods. Both groups consumed habitual Western diets made from conventional foods before and after the 2-wk intervention period. The primary outcome was UPRE. In addition, we assessed diet composition and pesticide residue profiles in foods eaten. Participants were aware of group assignment, but the study assessors were not.

RESULTS

During the intervention period, total UPRE was 91% lower with organic (mean 17 μg/d; 95% CI: 15, 19) than with conventional (mean 180 μg/d; 95% CI: 153, 208) food consumption (P < 0.0001). In the conventional group, switching from the habitual Western diet to the MedDiet increased insecticide excretion from 7 to 25 μg/d (P < 0.0001), organophosphate excretion from 5 to 19 μg/d (P < 0.0001), and pyrethroid residue excretion from 2.0 to 4.5 μg/d (P < 0.0001). Small but significant effects of sex were detected for chlormequat, herbicide, and total pesticide residue excretion.

CONCLUSIONS

Changing from a habitual Western diet to a MedDiet was associated with increased insecticide, organophosphate, and pyrethroid exposure, whereas organic food consumption reduced exposure to all groups of synthetic chemical pesticides. This may explain the positive health outcomes linked to organic food consumption in observational studies. This trial was registered at www.clinicaltrials.gov as NCT03254537.