Diet and Risk of Myeloproliferative Neoplasms in Older Individuals from the NIH-AARP Cohort

BACKGROUND: The etiology of myeloproliferative neoplasms (MPN) is obscure, and no previous studies have evaluated the role of diet. METHODS: In the NIH-AARP Diet and Health Study, a prospective cohort of 463,049 participants ages 50 to 71 years at baseline (1995-1996), we identified 490 MPN cases after a median follow-up of 15.5 years, including 190 with polycythemia vera (PV) and 146 with essential thrombocythemia (ET). We examined possible associations between various dietary factors and the risk of MPN as a group, as well as PV and ET, using multivariable Cox proportional hazards models to estimate hazard ratios (HR) and 95% confidence intervals (CI) and adjust for potential confounding variables. RESULTS: An increased risk was observed between fruit consumption and the risk of MPN overall (third tertile vs. first tertile, HR = 1.32; 95% CI, 1.04-1.67; Ptrend = 0.02) and PV (third tertile vs. first tertile, HR = 2.00; 95% CI, 1.35-2.95; Ptrend < 0.01). Increased risk of PV was also observed among those with high intake of sugar (HR = 1.77; 95% CI, 1.12-2.79), sugar from natural sources (HR = 1.77; 95% CI, 1.16-2.71), sugar from natural beverage sources (HR = 1.57; 95% CI, 1.08-2.29), and fructose (HR = 1.84; 95% CI, 1.21-2.79). CONCLUSIONS: The intake of fat and protein did not appear to influence PV risk-neither did meat or vegetable consumption. None of the dietary factors studied was associated with the risk of ET. The role of sugar intake in the etiology of PV in older individuals warrants further investigation. IMPACT: Our results indicate that high sugar intake is associated with an increased risk of polycythemia vera.