Substituting conventional with organic fruits and vegetable (F&V) appears to reduce the risk of postmenopausal cancer, suggests a study.
“Regular F&V consumption is linked to a lower risk of certain cancers,” the investigators said. “However, F&V can contain pesticides, some of which may have carcinogenic properties.”
A total of 31,179 participants (75 percent female) were included in the analyses. Multivariable Cox proportional hazards models were used to examine substitution of conventional with organic F&V per 100 g/day increase of substitution and by quintiles. The investigators also performed sensitivity analyses and used marginal structural models to improve causal inference.
During a mean follow-up of 7.3 years, 1,718 cancer cases (284 postmenopausal breast cancer) were recorded over 227,660 person-years. [Am J Clin Nutr 2026;123:101284]
Replacing conventional with organic F&V correlated with reduced risks of overall cancer (hazard ratio [HR], 0.98, 95 percent confidence interval [CI], 0.95‒1.00) and postmenopausal breast cancer (HR, 0.90, 95 percent CI, 0.85‒0.96). No association was observed for other types of cancer.
When modeled by quintiles, substituting conventional with organic F&V was inversely associated with postmenopausal breast cancer but not with overall cancer or other locations. These findings persisted when running marginal structural models and testing for additional adjustments.
“[S]ubstitution of conventionally grown F&V with organically grown F&V was associated with a lower risk of postmenopausal breast cancer,” the investigators said. “The specific role of organic F&V compared with conventional F&V needs further investigation in other contexts.”
Mechanisms
The association between postmenopausal breast cancer risk reduction and replacement of conventional with organic F&V could be explained by underlying mechanisms. For instance, organic consumers had lower exposure to pesticide residues. [Environ Health Perspect 2006;114:260-263; Environ Res 2014;132:105-111]
Pesticides can interact with genetic materials and cause DNA damage or chromosomal abnormalities or induce epigenetic modifications. Furthermore, xenobiotic chemicals can obstruct certain nuclear receptors, potentially resulting in the onset of chronic diseases such as cancer. [Toxicol Appl Pharmacol 2013; 268:157-177; Front Nutr 2024;11:1342881; PPAR Res 2011;2010:954639]
Some pesticides are also believed to be “endocrine disruptors, even at low doses, corresponding to pesticide residue levels in food,” the investigators said.
“Organophosphorus compounds can mimic estrogens and also disrupt carbohydrate and lipid metabolism, whereas organochlorine insecticides, carbamates, and triazines can block androgen receptors, which may be involved in the association observed for breast cancer,” they added.
Gut microbiota
With limited evidence, a previous study suggests a role played by gut microbiota in mediating the relationship between pesticide exposure and cancer risk. [Chemosphere 2019;227:425-434]
“All these mechanisms could be implied in carcinogenicity and explain the strong negative association between organic F&V and postmenopausal breast cancer risk, considering that the statistical power for the other sites was limited,” the investigators said. [Environ Int 2008;34:168-183]
“Nevertheless, some literature suggests that some biological compounds contained in F&V may mitigate the potential harms related to pesticide exposure, particularly by detoxification mechanisms,” they added. [J Environ Health Sci Eng 2022;20:1035-1045]