Dietary Intake Mediates Ethnic Differences in Gut Microbial Composition.

Background: The human gut microbiome (GM) has been observed to vary by race/ethnicity. Objective: Assess whether racial/ethnic GM variation is mediated by differences in diet. Design: Stool samples collected from 2013 to 2016 from 5267 healthy Multiethnic Cohort participants (age 59−98) were analyzed using 16S rRNA gene sequencing to estimate the relative abundance of 152 bacterial genera. For 63 prevalent genera (>50% in each ethnic group), we analyzed the mediation of GM differences among African Americans, Japanese Americans, Latinos, Native Hawaiians, and Whites by overall diet quality (Healthy Eating Index score (HEI-2015)) and intake amounts of 14 component foods/nutrients assessed from 2003 to 2008. For each significant mediation (p < 1.3 × 10−5), we determined the percent of the total ethnicity effect on genus abundance mediated by the dietary factor. Results: Ethnic differences in the abundance of 12 genera were significantly mediated by one or more of eight dietary factors, most frequently by overall diet quality and intakes of vegetables and red meat. Lower vegetable intake mediated differences in Lachnospira (36% in African Americans, 39% in Latinos) and Ruminococcus-1 (−35% in African Americans, −43% in Latinos) compared to Native Hawaiians who consumed the highest amount. Higher red meat intake mediated differences in Lachnospira (−41%) and Ruminococcus-1 (36%) in Native Hawaiians over African Americans, who consumed the least. Dairy and alcohol intakes appeared to mediate and counterbalance the difference in Bifidobacterium between Whites and Japanese Americans. Conclusions: Overall diet quality and component food intakes may contribute to ethnic differences in GM composition and to GM-related racial/ethnic health disparities.

Disparity in liver cancer incidence and chronic liver disease mortality by nativity in Hispanics: The Multiethnic Cohort.

BACKGROUND: Hepatocellular carcinoma (HCC) and chronic liver disease (CLD) are major causes of morbidity and mortality among Hispanics. Disparities in the incidence of HCC and in CLD deaths by nativity in Hispanics have been reported. Whether individual-level risk factors could explain these disparities was assessed in a prospective study of 36,864 Hispanics (18,485 US-born and 18,379 foreign-born) in the Multiethnic Cohort. METHODS: Risk factors were assessed with a baseline questionnaire and Medicare claim files. During a 19.6-year follow-up, 189 incident cases of HCC and 298 CLD deaths were identified. RESULTS: The HCC incidence rate was almost twice as high for US-born Hispanic men versus foreign-born Hispanic men (44.7 vs 23.1), but the rates were comparable for women (14.5 vs 13.4). The CLD mortality rate was about twice as high for US-born Hispanics versus foreign-born Hispanics (66.3 vs 35.1 for men and 42.2 vs 19.7 for women). Heavy alcohol consumption was associated with HCC and CLD in foreign-born individuals, whereas the current smoking status, hepatitis B/C viral infection, and diabetes were associated with both HCC and CLD. After adjustments for these risk factors, the hazard rate ratios for HCC and CLD death were 1.58 (95% confidence interval, 1.00-2.51) and 1.85 (95% confidence interval, 1.25-2.73), respectively, for US-born Hispanics versus foreign-born Hispanics. CONCLUSIONS: US-born Hispanics, particularly males, are at greater risk for HCC and death from CLD than foreign-born Hispanics. Overall known differences in risk factors do not account for these disparities. Future studies are warranted to identify factors that contribute to the elevated risk of HCC development and CLD death in US-born Hispanics. Cancer 2016;122:1444-1452. © 2016 American Cancer Society.

Intersection of Race/Ethnicity and Socioeconomic Status in Mortality After Breast Cancer.

We investigated social disparities in breast cancer (BC) mortality, leveraging data from the California Breast Cancer Survivorship Consortium. The associations of race/ethnicity, education, and neighborhood SES (nSES) with all-cause and BC-specific mortality were assessed among 9372 women with BC (diagnosed 1993-2007 in California with follow-up through 2010) from four racial/ethnic groups [African American, Asian American, Latina, and non-Latina (NL) White] using Cox proportional hazards models. Compared to NL White women with high-education/high-nSES, higher all-cause mortality was observed among NL White women with high-education/low-nSES [hazard ratio (HR) (95 % confidence interval) 1.24 (1.08-1.43)], and African American women with low-nSES, regardless of education [high education HR 1.24 (1.03-1.49); low-education HR 1.19 (0.99-1.44)]. Latina women with low-education/high-nSES had lower all-cause mortality [HR 0.70 (0.54-0.90)] and non-significant lower mortality was observed for Asian American women, regardless of their education and nSES. Similar patterns were seen for BC-specific mortality. Individual- and neighborhood-level measures of SES interact with race/ethnicity to impact mortality after BC diagnosis. Considering the joint impacts of these social factors may offer insights to understanding inequalities by multiple social determinants of health.

Differences by race/ethnicity in older adults' beliefs about the relative importance of dietary supplements vs prescription medications: results from the SURE Study.

Dietary supplement use is widespread among adults across races/ethnicities, yet reasons for use can vary across these groups. The Supplement Reporting (SURE) study quantified dietary supplement use and reasons for taking supplements in a multiethnic sample of adults who took at least one supplement. This study explored sociodemographic differences, including by race/ethnicity, associated with specific reasons/motivations for taking dietary supplements, including perceived importance of taking supplements relative to prescription medications. The study time period was March 2005 to August 2006. Participants (n=397) were older adults (ages 52 to 88 years) recruited from the Multiethnic Cohort Study in Hawaii and Los Angeles, CA, with equal representation of males and females from six ethnic groups (ie, white, Japanese American, Native Hawaiian, African American, US-born Latino, and foreign-born Latino). Subgroups of participants were compared by χ(2) tests and logistic regression. The most common reasons for taking supplements were to maintain a healthy life, because they were recommended by a health professional, and to prevent a disease/medical problem. A majority (76%) of participants reported that their dietary supplements were as important as prescription medications, with foreign-born Latinos and Japanese Americans being most likely to state this belief. The relative importance of supplements was not associated with excessive use, but 27% of participants exceeded the upper limit for a nutrient. It is crucial for health professionals to better understand why individuals take supplements and the importance that they attach to their use. This information could lead to better monitoring and education efforts to prevent overuse of supplements and possible interactions with medications.

Adherence to the food guide pyramid recommendations among African Americans and Latinos: results from the Multiethnic Cohort.

The objective of the study was to determine the degree of adherence to the Food Guide Pyramid recommendations among African Americans, Latinos born in the United States, and Latinos born in Mexico. Subjects were from the Multiethnic Cohort Study in Hawaii and Los Angeles, and completed a self-administered quantitative food frequency questionnaire at baseline in 1993-1996. Dairy recommendations were the least likely of all the food group recommendations to be followed, with 61% to 99% of individuals in the three ethnic groups not consuming the recommended number of servings. African Americans were less likely to adhere to all of the food group recommendations compared to the two Latino groups. A greater percentage of Latinos born in the United States did not adhere to the food group recommendations compared to Latinos born in Mexico. All three groups would benefit from interventions designed to promote healthy food choices.