Diet impacts mortality from cancer: results from the multiethnic cohort study

Cancer is the second leading cause of death in the United States and mortality varies by ethnicity. The objective of this study was to examine the association between cancer mortality and dietary intake among a large multiethnic population.

A prospective cohort design was used to examine cancer mortality among 146,389 participants. Multiethnic cohort study participants represent five ethnic groups: African American, Native Hawaiian, Japanese American, Latino, and Caucasian. Hazard ratios for cancer mortality by intake levels of five food groups and discretionary fat were calculated using Cox proportional hazards models stratified by sex and ethnicity.

There were a total of 2,028 male and 1,464 female fatal cancer cases at the end of follow-up. Among Japanese American men only, there was a significant protective effect seen in those reporting a high grain intake (HR = 0.49, 95 % CI 0.35-0.69); there was no effect of grain consumption in any other ethnic-sex group. There was no evidence that ethnicity modified associations between fruit, vegetable, meat, dairy, or discretionary fat intake and cancer mortality among men. Associations between food group consumption and risk for cancer mortality among women were similar across ethnic groups.

The considerable reduction in cancer risk associated with high grain consumption among a specific ethnic-sex group, Japanese American men, warrants further investigation. Additional research is needed to validate this observation and determine whether this was a chance finding, or possibly due to differential intake of specific grain subtypes, and/or related to a sex-specific cancer type.