Long-term neighborhood ethnic composition and weight-related outcomes among immigrants: The Multi-Ethnic Study of Atherosclerosis

Ethnic Enclaves and Incidence of Cancer Among US Ethnic Minorities in the Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Since immigrants and their descendants represent a growing proportion of the US population, there is a strong demographic imperative for scientists to better understand the cancer risk factors at multiple levels that exist for these populations. Understanding the upstream causes of cancer, including neighborhood context, may help prevention efforts. Residence in ethnic enclaves may be one such contextual cause; however, the evidence is mixed, and past research has not utilized prospective designs examining cancer incidence or mortality.

METHODS

We examined the association between residency in ethnic enclaves and cancer events among Hispanic (n = 753) and Chinese (n = 451) participants without a history of cancer in the Multi-Ethnic Study of Atherosclerosis (MESA), a prospective cohort study that enrolled participants ages 45-84 in six US cities. Cancer events included deaths and hospitalization for any cancer diagnosis from 2000-2012. Residency in an ethnic enclave was operationalized as their geocoded baseline census tract having a concentration of residents of the same ethnicity greater than the 75th percentile (compared to non-ethnic enclave otherwise). Potential confounders were blocked into three categories: sociodemographic, acculturation, and biomedical/health behavior variables. To examine the association between ethnic enclaves and cancer, we estimated hazard ratios (HRs) and 95% confidence intervals (CIs) using Cox proportional hazards models.

RESULTS

Among Hispanic participants, residing in ethnic enclaves (vs. not) was associated with a 39% reduction in cancer risk (HR 0.61, 95%CI: 0.31, 1.21) after adjusting for sociodemographic variables. Among Chinese participants, residing in ethnic enclaves was associated with a 2.8-fold increase in cancer risk (HR 2.86, 95%CI; 1.38, 5.94) after adjusting for sociodemographic variables.

CONCLUSIONS

Our results suggest that the association between ethnic enclaves and cancer events differs by ethnic group, suggesting that different social and contextual factors may operate in different communities.

Beneficial Effects of a Low-Glycemic Diet on Serum Metabolites and Gut Microbiota in Obese Women With Prevotella and Bacteriodes Enterotypes: A Randomized Clinical Trial

Generalized healthy eating patterns may not benefit everyone due to different genetics and enterotypes. We aimed to compare the effects of a low-glycemic diet representing the Korean traditional balanced diet (Low-GID) and westernized diet as a control diet (CD) on anthropometry, serum metabolites, and fecal bacteria in a randomized clinical trial according to enterotypes. We recruited 52 obese women aged 30-50 years, and they consumed Low-GID and CD meals for 1 month, with a 1-month washout period, in a crossover randomized clinical trial. The Low-GID was mainly composed of whole grains with fish, vegetables, seaweeds, and perilla oil, whereas CD contained refined rice, bread, noodles, meats, and processed foods. Serum lipid profiles, metabolomics, serum short-chain fatty acids, and fecal bacteria were analyzed. The important variables influenced by Low-GID and CD were determined by SHAP value in the XGBoost algorithm according to Bacteroides (ET-B) and Prevotella (ET-P). Low-GID and CD interventions did not change the enterotypes, but they modified serum metabolites and some fecal bacterial species differently according to enterotypes. The 10-fold cross-validation of the XGBoost classifier in the ET-P and ET-B clusters was 0.91 ± 0.04 and 0.8 ± 0.07, respectively. In the ET-P cluster, serum L-homocysteine, glutamate, leucine concentrations, and muscle mass were higher in the CD group than in the Low-GID group, whereas serum 3-hydroxybutyric acid concentration was significantly higher in the Low-GID group than in the CD group (p < 0.05). In fecal bacteria, Gemmiger formicilis, Collinsella aerofaciens, and Escherichia coli were higher in the CD group than in the Low-GID group. In the ET-B cohort, serum tryptophan and total cholesterol concentrations were higher in the CD group than in the Low-GID group, whereas serum glutathione and 3-hydroxybutyric acid concentrations were significantly higher in the Low-GID group than in the CD group (p < 0.05). However, Bifidobacterium longum was higher in CD than Low-GID in the ET-B cluster, but serum butyric acid levels were higher in the Low-GID than in the CD group. In conclusion, Low-GID can be recommended in obese women with both ET-P and ET-B enterotypes, although its efficacy was more effective in ET-P.

Clinical Trial Registration

[https://cris.nih.go.kr/cris/search/detailSearch.do/17398], identifier [KCT0005340].