Consumption of fruits, vegetables, and risk of hematological malignancies: a systematic review and meta-analysis of prospective studies

We examined the association between fruit/vegetable consumption and the risk of hematological malignancies in cohort studies (end of search: August 31, 2016). Total fruit consumption was not associated with the risk of non-Hodgkin lymphoma (NHL) (RR=1.03, 95%CI: 0.92-1.16, I-2=12.1%, n=7), acute myeloid leukemia (RR=1.23, 95% CI: 0.94-1.61, I-2=0%, n=3), multiple myeloma (MM; RR=1.05, 95%CI: 0.72-1.55, I-2=60.0%, n=4), and Hodgkin lymphoma. However, citrus fruit consumption was associated with reduced NHL risk (RR=0.85, 95%CI: 0.73-1.00, p=.044, I-2=0%, n=6). Vegetable intake was marginally associated with reduced NHL risk (RR=0.89, 95% CI: 0.79-1.00, p=.056, I-2=16.2%, n=7), but not with acute myeloid leukemia, multiple myeloma, and Hodgkin lymphoma risk. Nevertheless, NHL risk was inversely associated with cruciferous vegetable consumption (RR=0.84, 95% CI: 0.71-1.00, p=.047, I-2=0%, n=3). Notably, combined fruit/vegetable consumption was associated with decreased NHL risk (RR=0.79, 95% CI: 0.65-0.96, I-2=11.2%, n=3). This meta-analysis reveals possible protective effects; however, confounding and reporting bias could have affected the results.