What’s the latest on The Dirty Dozen?
Posted:
2024-04-22
What’s happening?
The American not-for-profit Environmental Working Group (EWG) has recently published an updated 2024 Dirty DozenTM, which, according to their analysis, lists fruit and vegetables most contaminated with pesticides (1). The report relies on federal government data that selects a subset of fruit and vegetables and tests food samples based on how fruit and vegetables are typically prepared and eaten at home (1). Pesticides are agents used to protect crops and are classified according to their function: insecticides for insects, rodenticides for rodents, herbicides for weeds, and fungicides to control fungi, mould and mildew (2).
The EWG maintains that children are most likely to be susceptible to pesticide exposure and related health consequences, which has led to the American Academy of Pediatrics listing the Dirty DozenTM as a resource for information on pesticide residues in produce (3). According to the EWG, substituting organic produce for conventional fruit and vegetables is one way to reduce exposure to pesticide residues (1). However, the ultimate recommendation is for individuals to eat more fruit and vegetables, regardless of whether they are conventionally or organically grown.
Criticism of the Dirty DozenTM suggests the list overstates the risk to consumers (4), limiting the inclusion of diverse foods in consumers’ diets (5). Given the recent media attention on the updated Dirty DozenTM list publication, the PEN Team decided to explore the EWG’s analysis and identify implications for dietetic practice.
Analysis
Six pesticide contamination measures were used on popular fruit and vegetables collected by the Agriculture Department and the Food and Drug Administration (1). The final score of the produce was the sum of the six criteria. For the 2024 report, the group stated that 47,150 samples of 46 fruit and vegetables were studied, with 75% containing pesticides. A total of 209 different pesticides were identified on the Dirty DozenTM list, with at least 50 varieties of pesticide residue detected on most items. The analysis is based on the number of different pesticide residues but does not look at the cumulative level of residues. The group suggests the possibility of interaction between residues; however, the results focus on the potential unknown effects of pesticide residues, not the known risks of pesticides.
Exposure Versus Risk
Dietary exposure does not equate to risk. The rankings do not indicate that the produce samples exceeded U.S. tolerances. An independent analysis of the EWG’s earlier report suggests that all pesticide exposure estimates were well below the established reference values that are strictly monitored and regulated (6). Furthermore, the methodology used to create the Dirty DozenTM list detected pesticide residues without relating residue exposure to health outcomes, which limits the ability to establish causation. The study authors concluded that exposure to commonly detected pesticides poses negligible risk to consumers (6). Small amounts of pesticide residues left on food are low enough not to cause harm (7).
Organic Versus Conventional Produce
Many countries have specific standards and expectations for producers and processors of organic foods (8). Organic crops emphasize soil quality, limited use of herbicides and insecticides and do not use genetically modified organism seeds (8). However, consuming organic produce does not mean that the produce is pesticide free (6), only that certain substances have not been used (9). For example, the Canadian Organic Standards allow for produce to be grown using pest control products included in the Permitted Substances List. Organic standards in other jurisdictions follow a similar model (9). There is a lack of evidence recommending organic food consumption for long-term health benefits (10). Evidence suggests reduced pesticide metabolite excretion when transitioning from a conventional to an organic diet. Still, more research is needed to explore the direct health outcomes of organic diet interventions.
What now?
As a result of this analysis, the PEN Team recently updated the Food Safety -
Food Safety - Pesticides/Herbicides Background to exclude information on the Dirty Dozen
TM to better reflect the state of the evidence and dietary implications and recommendations.
Dietitians can consider the following when providing consumer information on produce selection:
- Provide evidence-based information on the use of pesticides. Pesticides protect food crops (2). Governments monitor and evaluate the use of pesticides to determine the safety and quality of pesticide residue on foods (7). Strict limits for pesticide residues are set, with particular attention placed on protecting vulnerable individuals at higher risk of pesticide harm (infants, children and older adults and during pregnancy) and are reviewed annually (7,11,12).
- Describe the established health benefits of increased fruit and vegetable consumption. This includes the primary prevention of cardiovascular disease (13) and cancer (14). Encourage clients to feel confident about choosing any types of produce available.
- Educate and advocate for increased fruit and vegetable intake. In Canada, some evidence suggests that vegetable and fruit consumption trends are decreasing (15). Greater investment in awareness, education and public policy is needed to improve intake (16).
- Keep a client-centered approach. Given the increased food prices worldwide (17), it is important to consider the additional cost of consuming organic foods as part of clients' overall eating patterns. Dietitians can advise their clients to weigh the extra cost of organic foods against the limited evidence to support their health benefits (10). Promoting organic food as more nutritious than conventional food can potentially hinder individuals' ability to meet their fruit and vegetable recommendations. It is important to establish a supportive counsellor-client relationship to set food and nutrition priorities, goals, and action plans (18).
- Provide evidence-informed recommendations. Communicate that possible health benefits associated with consuming organic foods may also be related to the benefits of consuming more plant-based foods (19). Use a health disparities lens that focuses on the importance of consistent access, availability and affordability of nutritious foods when making eating pattern recommendations (20).
Additional Content
Professional
Consumer
- Related to Fruits and Vegetables:
Reviewed by the Canadian Produce Marketing Association.
References
- The Environmental Working Group. 2024 Mar. Available from: https://www.ewg.org/foodnews/summary.php#methodology
- Dietitians of Canada. Food Safety - Pesticides/Herbicides Background. In: Practice-based Evidence in Nutrition ® [PEN]. 2021 Mar 19 [cited 2024 Apr 12]. Available from: https://www.pennutrition.com/KnowledgePathway.aspx?kpid=2536&trid=17061&trcatid=38. Access only by subscription. Click Sign Up on PEN login page.
- The American Academy of Pediatrics. 2024 Mar. Available from: https://www.aap.org/en/patient-care/environmental-health/promoting-healthy-environments-for-children/food-safety/
- American Council on Science and Health. 2024 Apr 9. Available from: https://www.acsh.org/news/2024/02/06/if-your-child-can%E2%80%99t-eat-more-340-medium-apples-day-you-can-skip-organics-17625
- Immunologic. Organic foods are not healthier…or pesticide free. 2024 Mar 22. Available from: https://immunologic.substack.com/p/organic-foods-are-not-healthieror?utm_campaign=email-half-post&r=y8qt2&utm_source=substack&utm_medium=email
- Winter CK, Katz JM. Dietary exposure to pesticide residues from commodities alleged to contain the highest contamination levels. J Toxicol. 2011;2011:589674. Doi: 10.1155/2011/589674. Epub 2011 May 15. PMID: 21776262; PMCID: PMC3135239. Abstract available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3135239/
- Government of Canada. Pesticide assessments in Canada: Introduction. 2023 Nov 28. Available from: https://www.canada.ca/en/health-canada/services/consumer-product-safety/pesticides-pest-management/public/protecting-your-health-environment/pesticide-assessments.html
- Dietitians of Canada. Organic Food Background. In: Practice-based Evidence in Nutrition ® [PEN]. 2021 Apr 7 [cited 2024 Apr 12]. Available from: https://www.pennutrition.com/KnowledgePathway.aspx?kpid=2536&trid=11647&trcatid=38. Access only by subscription. Click Sign Up on PEN login page.
- Government of Canada. Organic production systems: permitted substances lists. 2013 Apr 3. Available from: https://www.publications.gc.ca/site/eng/9.894398/publication.html
- Dietitians of Canada. Are there health benefits from consuming organic foods compared to conventionally farmed foods? In: Practice-based Evidence in Nutrition ® [PEN]. 2022 Nov 2 [cited 2024 Apr 12]. Available from: https://www.pennutrition.com/KnowledgePathway.aspx?kpid=11365&pqcatid=146&pqid=11626. Access only by subscription. Click Sign Up on PEN login page.
- Food Standards Australia and New Zealand. Chemicals in food - maximum residue limits. 2022 Nov. Available from: https://www.foodstandards.gov.au/consumer/chemicals/maxresidue
- GOV.uk. Expert Committee on Pesticide Residues in Food (PRif). 2023 Jan 19. Available from: https://assets.publishing.service.gov.uk/media/63c91164d3bf7f24b0334ff0/The_Expert_Committee_on_Pesticide_Residues_in_Food_Annual_Report_2021.pdf
- Dietitians of Canada. Are diets higher in total dietary fibre (including whole grains, cereals, vegetables, fruit and legume/pulse fibre) recommended for primary or secondary cardiovascular disease (CVD) prevention? In: Practice-based Evidence in Nutrition ® [PEN]. 2019 Dec 10 [cited 2024 Apr 12]. Available from: https://www.pennutrition.com/KnowledgePathway.aspx?kpid=674&pqcatid=146&pqid=28050. Access only by subscription. Click Sign Up on PEN login page.
- Dietitians of Canada. What nutrients/dietary factors are associated with a decreased risk of developing cancer? In: Practice-based Evidence in Nutrition ® [PEN]. 2022 Mar 12 [cited 2024 Apr 12]. Available from: https://www.pennutrition.com/KnowledgePathway.aspx?kpid=8996&pqcatid=145&pqid=8967. Access only by subscription. Click Sign Up on PEN login page.
- Charlebois S, Music J, Rupasinghe HPV. Taking Stock of Fruit and Vegetable Consumption in Canada: Trends and Challenges. Dietetics. 2023;2(1):23-33. Abstract available from: https://www.mdpi.com/2674-0311/2/1/2
- Wallace TC, Bailey RL, Blumberg JB, Burton-Freeman B, Chen CO, Crowe-White KM, Drewnowski A, Hooshmand S, Johnson E, Lewis R, Murray R, Shapses SA, Wang DD. Fruits, vegetables, and health: a comprehensive narrative, umbrella review of the science and recommendations for enhanced public policy to improve intake. Crit Rev Food Sci Nutr. 2020;60(13):2174-2211. doi: 10.1080/10408398.2019.1632258. Epub 2019 Jul 3. PMID: 31267783. Abstract available from: https://pubmed.ncbi.nlm.nih.gov/31267783/
- International Food Policy Research Institute. Despite improved global market conditions, high food price inflation persists. 2023 Dec 4. Available from: https://www.ifpri.org/blog/despite-improved-global-market-conditions-high-food-price-inflation-persists#:~:text=Consumer%20food%20price%20inflation%20remains,inflation%20of%20more%20than%2015%25.
- Dietitians of Canada. Counselling Models Background. In: Practice-based Evidence in Nutrition ® [PEN]. 2024 Feb 8 [cited 2024 Apr 12]. Available from: https://www.pennutrition.com/KnowledgePathway.aspx?kpid=2197&trcatid=38&trid=2195.Click Sign Up on PEN login page.
- Glibowski P. Organic food and health. Rocz Panstw Zakl Hig. 2020;71(2):131-136. doi: 10.32394/rpzh.2020.0110. PMID: 32519524. Abstract available from: https://pubmed.ncbi.nlm.nih.gov/32519524/
- Dietitians of Canada. Can Prescribing Produce Help Manage Type 2 Diabetes? In Practice-based Evidence in Nutrition ® [PEN]. 2023 Aug 21 [cited 2024 Apr 12]. Available from: https://www.pennutrition.com/TrendingTopic.aspx?id=30328 2023-08-21. Access only by subscription. Click Sign Up on PEN login page.