Dietary intake of fruit and vegetables and risk of non-Hodgkin lymphoma.

Objective: Few studies have evaluated the potential association between consumption of fruit and vegetables and non-Hodgkin lymphoma (NHL) by histologic subtype, and the results of these studies have been inconsistent.
Methods: A detailed history of dietary practices and food preferences was collected using a food frequency questionnaire from 348 cases and 470 controls in a population-based, case-control study conducted in Nebraska during 1999-2002. Risk for the highest versus lowest quartile or tertile of intake was estimated by odds ratios (ORs) and 95% confidence interval (CIs).
Results: A lower risk of overall NHL was associated with a high intake of green leafy vegetables (OR = 0.6; CI = 0.3-1.0) and cruciferous vegetables (OR = 0.7; CI = 0.4-1.0). Analysis by subtype showed that green leafy vegetable intake was associated with a lower risk of follicular lymphoma (OR = 0.5; CI = 0.3-0.8) and diffuse large B-cell lymphoma (DLBCL) (OR = 0.5; CI = 0.3-0.9), while consumption of cruciferous vegetables was associated with a lower risk of DLBCL (OR = 0.4; CI = 0.2-0.8). No association was found with intake of total vegetables, carotene-rich vegetables, or all fruit. For nutrients, the risk of NHL overall was inversely associated with a higher intake of β-cryptoxanthin (OR = 0.6; CI = 0.4-0.9), magnesium (OR = 0.4; CI = 0.2-0.6), potassium (OR = 0.5; CI = 0.3-1.0), and fiber (OR = 0.6; CI = 0.3-1.0), but positively associated with a higher intake of retinol (OR = 1.7; CI = 1.1-2.8). Intakes of vitamin E, magnesium, and potassium were inversely associated with the risk of DLBCL.
Conclusion: A higher intake of green leafy vegetables and cruciferous vegetables is associated with a lower risk of NHL overall, particularly follicular lymphoma and DLBCL.