A study published in JAMA Internal Medicine found that, in a study of 68 946 French adults, a significant reduction in the risk of cancer was observed among high consumers of organic food.  In the study, those who ate more organic produce, dairy, meat and other products had 25 percent fewer cancer diagnoses overall, especially of lymphoma, non-Hodgkin lymphoma and breast cancer.

Read an article about the study here.

Among the environmental risk factors for cancer, there are concerns about exposure to different classes of pesticides, notably through occupational exposure.³ A recent review⁴ concluded that the role of pesticides for the risk of cancer could not be doubted given the growing body of evidence linking cancer development to pesticide exposure. While dose responses of such molecules or possible cocktail effects are not well known, an increase in toxic effects has been suggested even at low concentrations of pesticide mixtures.⁵

Organic food standards do not allow the use of synthetic fertilizers, pesticides, and genetically modified organisms and restrict the use of veterinary medications.¹¹ As a result, organic products are less likely to contain pesticide residues than conventional foods.^12,13