Risk of lymphoma subtypes and dietary habits in a Mediterranean area

Background Previous studies have suggested that diet might affect risk of lymphoma subtypes. We investigated risk of lymphoma and its major subtypes associated with diet in the Mediterranean island of Sardinia, Italy. Methods In 1998–2004, 322 incident lymphoma cases and 446 randomly selected population controls participated in a case-control study on lymphoma etiology in central-southern Sardinia. Questionnaire interviews included frequency of intake of 112 food items. Risk associated with individual dietary items and groups thereof was explored by unconditional and polytomous logistic regression analysis, adjusting by age, gender and education. Results We observed an upward trend in risk of lymphoma (all subtypes combined) and B-cell lymphoma with frequency of intake of well done grilled/roasted chicken ( p for trend=0.01), and pizza ( p for trend=0.047), Neither adherence to Mediterranean diet nor a frequent intake of its individual components conveyed protection. We detected heterogeneity in risk associated with several food items and groups thereof by lymphoma subtypes although we could not rule out chance as responsible for the observed direct or inverse associations. Conclusions Adherence to a Mediterranean diet does not seem to convey protection against the development of lymphoma. The association with specific food items might vary by lymphoma subtype.