Dietary isoflavone intake is not statistically significantly associated with breast cancer risk in the Multiethnic Cohort.

Given the high intake levels of soya and low incidence rates of breast cancer in Asian countries, isoflavones, substances with an oestrogen-like structure occurring principally in soyabeans, are postulated to be cancer protective. In the present study, we examined the association of dietary isoflavone intake with breast cancer risk in 84,450 women (896 in situ and 3873 invasive cases) who were part of the Multiethnic Cohort (Japanese Americans, whites, Latinos, African Americans and Native Hawaiians) with a wide range of soya intake levels. The absolute levels of dietary isoflavone intake estimated from a baseline FFQ were categorised into quartiles, with the highest quartile being further subdivided to assess high dietary intake. The respective intake values for the quartiles (Q1, Q2, Q3, and lower and upper Q4) were 0-< 3·2, 3·2-< 6·7, 6·7-< 12·9, 12·9-< 20·3, and 20·3-178·7 mg/d. After a mean follow-up period of 13 years, hazard ratios (HR) and 95% CI were calculated using Cox regression models stratified by age and adjusted for known confounders. Linear trends were tested by modelling continuous variables of interest assigned the median value within the corresponding quartile. No statistically significant association was observed between dietary isoflavone intake and overall breast cancer risk (HR for upper Q4 v. Q1: 0·96 (95% CI 0·85, 1·08); P trend = 0·40). While the test for interaction was not significant (P=0·14), stratified analyses suggested possible ethnic/racial differences in risk estimates, indicating that higher isoflavone intakes may be protective in Latina, African American and Japanese American women. These results are in agreement with those of previous meta-analyses showing no protection of isoflavones at low intake levels, but suggesting inverse associations in populations consuming high amounts of soya.

What Matters When Children Play: Influence of Social Cognitive Theory and Perceived Environment on Levels of Physical Activity Among Elementary-Aged Youth.

OBJECTIVES: Social Cognitive Theory (SCT) has often been used as a guide to predict and modify physical activity (PA) behavior. We assessed the ability of commonly investigated SCT variables and perceived school environment variables to predict PA among elementary students. We also examined differences in influences between Hispanic and non-Hispanic students. DESIGN: This analysis used baseline data collected from eight schools who participated in a four-year study of a combined school-day curriculum and environmental intervention. METHODS: Data were collected from 393 students. A 3-step linear regression was used to measure associations between PA level, SCT variables (self-efficacy, social support, enjoyment), and perceived environment variables (schoolyard structures, condition, equipment/supervision). Logistic regression assessed associations between variables and whether students met PA recommendations. RESULTS: School and sex explained 6% of the moderate-to-vigorous PA models' variation. SCT variables explained an additional 15% of the models' variation, with much of the model's predictive ability coming from self-efficacy and social support. Sex was more strongly associated with PA level among Hispanic students, while self-efficacy was more strongly associated among non-Hispanic students. Perceived environment variables contributed little to the models. CONCLUSIONS: Our findings add to the literature on the influences of PA among elementary-aged students. The differences seen in the influence of sex and self-efficacy among non-Hispanic and Hispanic students suggests these are areas where PA interventions could be tailored to improve efficacy. Additional research is needed to understand if different measures of perceived environment or perceptions at different ages may better predict PA.

Ethnic differences and predictors of colonoscopy, prostate-specific antigen, and mammography screening participation in the multiethnic cohort.

PURPOSE: Given the relation between screening and improved cancer outcomes and the persistence of ethnic disparities in cancer mortality, we explored ethnic differences in colonoscopy, prostate-specific antigen (PSA), and mammography screening in the Multiethnic Cohort Study. METHODS: Logistic regression was applied to examine the influence of ethnicity as well as demographics, lifestyle factors, comorbidities, family history of cancer, and previous screening history on self-reported screening participation collected in 1999-2002. RESULTS: The analysis included 140,398 participants who identified as white, African American, Native Hawaiian, Japanese American, US born-Latino, or Mexican born-Latino. The screening prevalences overall were mammography: 88% of women, PSA: 45% of men, and colonoscopy: 35% of men and women. All minority groups reported 10-40% lower screening utilization than whites, but Mexican-born Latinos and Native Hawaiian were lowest. Men were nearly twice as likely to have a colonoscopy (OR=1.94, 95% CI=1.89-1.99) as women. A personal screening history, presence of comorbidities, and family history of cancer predicted higher screening utilization across modalities, but to different degrees across ethnic groups. CONCLUSIONS: This study confirms previously reported sex differences in colorectal cancer screening and ethnic disparities in screening participation. The findings suggest it may be useful to include personal screening history and family history of cancer into counseling patients about screening participation.

A systematic review of single health behavior change interventions vs. multiple health behavior change interventions among older adults.

Multiple behavior change is widely used to reduce targeted health behaviors; however, its effect on behaviors such as physical activity, nutrition, and alcohol and tobacco use among older adults remains inconclusive. The primary purpose of this systematic review was to evaluate the effects of single health behavior change (SHBC) interventions vs. multiple health behavior change (MHBC) interventions among older age individuals. PubMed was searched for publications on health behavior interventions from 2006 to 2011. Twenty-one randomized clinical trials assessed the effects of health behavior change in older individuals. Results were reviewed by a number of health behaviors and effectiveness. Results revealed that within SHBC interventions, physical activity or exercise behavior revealed that interventions were the most common and showed the most promise in influencing positive outcomes in physical activity behavior among community-dwelling older adults. There were too few MHBC studies identified to allow confident comparison to SHBC interventions. The MHBC field is still at an early stage within the older adult literature, and more attention is recommended to investigate if the benefits of MHBC apply to this age group.