No Association Observed between Coffee Intake and Risk of Non-Hodgkin Lymphoma among Postmenopausal Women

Background: Some preliminary studies indicate that components in coffee may have anticarcinogenic effects. However, the association between coffee-drinking habits and the risk of non-Hodgkin lymphoma (NHL) remain controversial. Objective: To examine the relationship between coffee intake and NHL incidence in a large prospective study of postmenopausal US women. Design and participants/setting: The participants included 74,935 women from the Women's Health Initiative Observational Study who were recruited from 1993 through 1998. Information about coffee-drinking habits was collected at baseline via self-administered questionnaires. Main outcome measures: Newly diagnosed NHL was validated by medical records and pathology records. Separate analyses were performed for the following three subtypes of NHL: diffuse large B-cell lymphoma (n = 244), follicular lymphoma (n = 166), and chronic lymphocytic leukemia/small lymphocytic lymphoma (n = 64). Statistical analyses performed: Age-adjusted and multivariable-adjusted Cox proportional hazards models were used to determine associations of coffee intake (specifically, the total amount of coffee consumed daily, coffee types, and coffee preparation methods) with risk of NHL. Results: A total of 851 women developed NHL during a median 18.34 years of follow-up (range = 0.01 to 24.30 years; ± 6.63 years). Overall, no associations were observed between coffee intake and risk of NHL regardless of the total amount of daily coffee intake (P value for trend = 0.90), caffeinated (P = 0.55) or decaffeinated coffee intake (P = 0.78), and filtered or unfiltered coffee intake (P = 0.91) after controlling for sociodemographic factors, lifestyle risk factors, and clinical risk factors/current medical conditions. No significant associations were observed between coffee intake with specific subtypes of NHL. A statistically significant interaction was found between alcohol intake, coffee intake, and incident NHL (P value for interaction = 0.02) based on the adjusted analysis. Specifically, among women who frequently consumed alcohol (> 7 drinks/week), those who had moderate coffee intake (2 to 3 c coffee/day) had a significantly reduced risk of developing NHL (hazard ratio 0.61, 95% CI 0.36 to 0.98), compared with those who did not drink coffee. Conclusions: The findings from this study do not support an association between coffee consumption and NHL risk, irrespective of the total amount of daily coffee intake, coffee types, or coffee preparation methods.