Background: Over the last decades, there has been a major increase in the organic agriculture area in addition to an increased public demand and purchase of organic foods. One reason for choosing organic foods is the expectation of beneficial health effects, although the existing evidence supporting these claims is limited.
 
Objective: We investigated the associations between organic food consumption, overall and by specific food groups, and the incidence of cancer.
 
Methods: The study is based on data from the Danish Diet, Cancer and Health cohort. Organic food consumption was reported for vegetables, fruits, dairy products, eggs, meat, and bread and cereal products in frequencies specified as never, sometimes, often, or always. These were combined into an overall organic food score by assigning values from 1-4 to the four frequencies and summing across the six food groups, yielding a score range 6-24. Overall organic food consumption was evaluated both as a continuous variable and in categories defined as never (score of 6), low (score of 7-12), medium (score of 13-18), and high consumption (score of 19-24). Organic food consumption of the specific food groups was analyzed using the original frequency categories and as ordinal variables taking the values 1-4. We followed 41,928 participants for a median of 15 years, during which 9,675 first cancer cases were identified in the Danish Cancer Registry. Cox proportional hazards models adjusted for sociodemographic and lifestyle factors were used to estimate associations between organic food consumption and cancer incidence.
 
Results: No association was observed between organic food consumption and overall cancer incidence. Compared with never consuming organic foods, higher overall organic food consumption was associated with a lower incidence of stomach cancer (low: HR=0.50, 95% CI: 0.32-0.78, medium: HR=0.50, 95% CI: 0.32-0.80, high: HR=0.54, 95% CI: 0.27-1.07, p-trend=0.09), and a higher incidence of non-Hodgkin lymphoma (low: HR=1.45, 95% CI: 1.01-2.10, medium: HR=1.35, 95% CI: 0.93-1.96, high: HR=1.97, 95% CI: 1.28-3.04, p-trend=0.05). Similar patterns were generally observed when analyzing organic food consumption of the specific food groups.
 
Conclusion: Our study does not support an association between overall organic food consumption and cancer incidence. The limited existing literature shows conflicting results regarding the risk of specific cancers.