Genetic associations with micronutrient levels identified in immune and gastrointestinal networks.

The discovery of vitamins and clarification of their role in preventing frank essential nutrient deficiencies occurred in the early 1900s. Much vitamin research has understandably focused on public health and the effects of single nutrients to alleviate acute conditions. The physiological processes for maintaining health, however, are complex systems that depend upon interactions between multiple nutrients, environmental factors, and genetic makeup. To analyze the relationship between these factors and nutritional health, data were obtained from an observational, community-based participatory research program of children and teens (age 6-14) enrolled in a summer day camp in the Delta region of Arkansas. Assessments of erythrocyte S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH), plasma homocysteine (Hcy) and 6 organic micronutrients (retinol, 25-hydroxy vitamin D3, pyridoxal, thiamin, riboflavin, and vitamin E), and 1,129 plasma proteins were performed at 3 time points in each of 2 years. Genetic makeup was analyzed with 1 M SNP genotyping arrays, and nutrient status was assessed with 24-h dietary intake questionnaires. A pattern of metabolites (met_PC1) that included the ratio of erythrocyte SAM/SAH, Hcy, and 5 vitamins were identified by principal component analysis. Met_PC1 levels were significantly associated with (1) single-nucleotide polymorphisms, (2) levels of plasma proteins, and (3) multilocus genotypes coding for gastrointestinal and immune functions, as identified in a global network of metabolic/protein-protein interactions. Subsequent mining of data from curated pathway, network, and genome-wide association studies identified genetic and functional relationships that may be explained by gene-nutrient interactions. The systems nutrition strategy described here has thus associated a multivariate metabolite pattern in blood with genes involved in immune and gastrointestinal functions.

Methylation potential associated with diet, genotype, protein, and metabolite levels in the Delta Obesity Vitamin Study.

Micronutrient research typically focuses on analyzing the effects of single or a few nutrients on health by analyzing a limited number of biomarkers. The observational study described here analyzed micronutrients, plasma proteins, dietary intakes, and genotype using a systems approach. Participants attended a community-based summer day program for 6-14 year old in 2 years. Genetic makeup, blood metabolite and protein levels, and dietary differences were measured in each individual. Twenty-four-hour dietary intakes, eight micronutrients (vitamins A, D, E, thiamin, folic acid, riboflavin, pyridoxal, and pyridoxine) and 3 one-carbon metabolites [homocysteine (Hcy), S-adenosylmethionine (SAM), and S-adenosylhomocysteine (SAH)], and 1,129 plasma proteins were analyzed as a function of diet at metabolite level, plasma protein level, age, and sex. Cluster analysis identified two groups differing in SAM/SAH and differing in dietary intake patterns indicating that SAM/SAH was a potential marker of nutritional status. The approach used to analyze genetic association with the SAM/SAH metabolites is called middle-out: SNPs in 275 genes involved in the one-carbon pathway (folate, pyridoxal/pyridoxine, thiamin) or were correlated with SAM/SAH (vitamin A, E, Hcy) were analyzed instead of the entire 1M SNP data set. This procedure identified 46 SNPs in 25 genes associated with SAM/SAH demonstrating a genetic contribution to the methylation potential. Individual plasma metabolites correlated with 99 plasma proteins. Fourteen proteins correlated with body mass index, 49 with group age, and 30 with sex. The analytical strategy described here identified subgroups for targeted nutritional interventions.

Academic partnerships and key leaders emerging from communities in the lower Mississippi Delta (LMD): a community-based participatory research model.

Collaboratively, the nutritional health problems of the Lower Mississippi Delta (LMD) region were examined and opportunities identified for conducting research interventions. To combat the nutritional health problems in the LMD, community residents yielded to a more comprehensive and participatory approach known as community-based participatory research (CBPR). Community residents partnered with academic researchers and other organizational entities to improve the overall quality of diet and health in their respective communities using CBPR. The collaborative work in the LMD focused on interventions conducted in each of three specific communities across three states: Marvell, Arkansas (Marvell NIRI), and its surrounding public school district; Franklin Parish in Louisiana (Franklin NIRI); and the city of Hollandale, Mississippi (Hollandale NIRI). This paper examined some of the research interventions conducted in Franklin, Hollandale, and Marvell NIRI respectively, how leadership emerged from each of these communities, and lessons learned as a result of the CBPR model.

Development and evaluation of WillTry. An instrument for measuring children's willingness to try fruits and vegetables.

This paper describes the development and evaluation of the WillTry instrument, a psychometric tool designed to measure children's willingness to try fruits and vegetables. WillTry surveys were interviewer-administered to 284 children in an elementary school and summer day camps located in rural Mississippi and Arkansas (United States) communities. Factor analysis was used to determine construct dimensionality. Additional evaluation included internal consistency, test-retest reliability, and predictive validity. Factor analysis suggested a single dimension for the food items. The WillTry food scale had substantial reliability (intraclass correlation coefficients between 0.61 and 0.80) and sufficient internal consistency (Cronbach's alpha > or = 0.70). Results of the regression analysis for percent consumption of foods offered on WillTry response confirmed the predictive validity of the instrument. The results of these analyses provide psychometric evidence for the use of the WillTry instrument as a measure of willingness to try fruits and vegetables in rural, southern US children 5-14 years of age.

Participatory development and implementation of a community research workshop: experiences from a community-based participatory research partnership.

BACKGROUND: Although community-based participatory research (CBPR) principles stress the importance of "equitable partnerships" and an "empowering and power-sharing process that attends to social inequalities," descriptions of actual projects often focus on the challenges confronted in academic-community partnerships. These challenges occur in the context of economic and power inequities and the frequently limited diversity of researchers. Less often does this discourse attend to the link between the principles of CBPR and their empowering potential for community members who internalize and use these principles to hold outside partners accountable to these ideals. OBJECTIVES: This article documents the participatory development and implementation of a community research workshop, the community and organizational contexts, the content of the workshop, and lessons learned. Workshop objectives included increasing community knowledge of the research process, positively impacting community members' perceptions and attitudes about research, and improving researchers' understanding of community knowledge, perceptions, and experiences with research. METHODS: This project was conducted as a part of the larger United States Department of Agriculture, Agriculture Research Service (USDA ARS) Delta Nutrition Intervention Research Initiative (Delta NIRI). The workshop was developed by a joint academic-community team in partnership with a community-based workshop advisory committee (WAC) and implemented in three rural communities of the lower Mississippi Delta. Development included a dry run with the WAC, a pilot workshop, and a focus group to refine the final content and format. CONCLUSIONS: Applying participatory principles to the development of the community research workshop resulted in the creation of a mutually acceptable workshop and co-learning experience that empowered community members in their involvement in other community research projects.

Personalizing nutrigenomics research through community based participatory research and omics technologies.

Personal and public health information are often obtained from studies of large population groups. Risk factors for nutrients, toxins, genetic variation, and more recently, nutrient-gene interactions are statistical estimates of the percentage reduction in disease in the population if the risk were to be avoided or the gene variant were not present. Because individuals differ in genetic makeup, lifestyle, and dietary patterns than those individuals in the study population, these risk factors are valuable guidelines, but may not apply to individuals. Intervention studies are likewise limited by small sample sizes, short time frames to assess physiological changes, and variable experimental designs that often preclude comparative or consensus analyses. A fundamental challenge for nutrigenomics will be to develop a means to sort individuals into metabolic groups, and eventually, develop risk factors for individuals. To reach the goal of personalizing medicine and nutrition, new experimental strategies are needed for human study designs. A promising approach for more complete analyses of the interaction of genetic makeups and environment relies on community-based participatory research (CBPR) methodologies. CBPR's central focus is developing a partnership among researchers and individuals in a community that allows for more in depth lifestyle analyses but also translational research that simultaneously helps improve the health of individuals and communities. The USDA-ARS Delta Nutrition Intervention Research program exemplifies CBPR providing a foundation for expanded personalized nutrition and medicine research for communities and individuals.

Documenting the need for nutrition and health intervention for middle-aged and older adults in the Lower Mississippi Delta region.

Multiple demographic, health, and environmental factors may influence the overall quality of diets among rural middle-aged and older adults. This project compared the diet quality of participants in Foods of Our Delta Survey (FOODS 2000) who were aged 55 years and older with national data. The data were assessed using 24-hour dietary recall methodology and a modified version of the United States Department of Agriculture Healthy Eating Index (HEI) that excluded the sodium component. The mean total Modified Healthy Eating Index (MHEI) study score was significantly lower than their counterparts from the national survey (61.0 +/- 0.68 vs. 65.6 +/- 3.65, P < 0.0001). Race and educational attainment were associated with higher MHEI scores. This study emphasized a critical need for implementing nutrition and health interventions in rural communities with special attention to subpopulations at risk.

Perceptions of factors influencing healthful food consumption behavior in the Lower Mississippi Delta: focus group findings.

OBJECTIVE: To identify perceptions of Lower Mississippi Delta (LMD) residents regarding factors that influence a change in healthful food consumption behavior to assist in planning sustainable nutrition interventions in the LMD. DESIGN: Nine focus groups were conducted with LMD residents in 9 counties in Arkansas, Louisiana, and Mississippi. One focus group was held in each county on the topical area of behavioral change. SETTING: Nine counties in Arkansas, Louisiana, and Mississippi. PARTICIPANTS: The study population included 91 persons, 85 females and 6 males (18-60+ years of age), of whom 71 were African Americans, 17 were Caucasians, and 3 were Hispanics, who participated in the focus group discussions. ANALYSIS: Data analyses were completed by general and specific content coding. Data were reviewed for emerging themes for each topic. The Social Cognitive Theory served as the framework for understanding the determinants of a change in healthful food consumption behavior. RESULTS: The study showed considerable variability in perceptions that are influenced by both personal and external factors. These factors include health concerns, family influence, and need for and availability of nutrition information. Participants were interested in learning about healthful eating, food preparation skills, and portion control. CONCLUSIONS: Focus groups in the LMD identified many important themes relevant to the development of nutrition interventions in these communities. These data will be used to guide the community-based participatory interventions that will be developed and implemented in the LMD. The findings could be applicable to other researchers designing interventions for similar populations.

Food composition data: the foundation of dietetic practice and research.

Food composition databases and dietary assessment systems are important tools for food and nutrition professionals. The availability and accessibility of data have improved over time along with the technology to convert the information into useful formats for planning diets, writing educational materials, counseling patients, and conducting research. Primary sources of food composition data include government, academic, and other institutional databases; the food industry; and scientific literature. Changes in the marketplace affect food availability and composition and affect the accuracy and adequacy of food composition databases. Improvements in both food composition data and in dietary assessment methods have worked synergistically to improve estimates of dietary intake. The development of databases for food frequency assessment systems requires special considerations for data aggregation for each food or food grouping in the questionnaires. Considerations for selecting a dietary assessment system include appropriateness of the data for the intended audience or purpose, efficiency of the search strategy for retrieving data, content and format of summary information, and cost. Needs for food composition data vary depending on dietetic practice area; however, most food and nutrition professionals will benefit from becoming more informed about food composition data, exploring new ways to educate themselves about databases and database systems, and advocating for what is most needed in dietetic practice.

Poverty and food intake in rural America: diet quality is lower in food insecure adults in the Mississippi Delta.

OBJECTIVE: To determine if measures of diet quality differ between food insecure and food secure adults in a rural high-risk population. DESIGN: Random digit dialing telephone survey of a cross-section of the population designed to collect data on food intake, household demographics, and food security status. SETTING: A representative sample of adults who live in 36 counties in the Lower Mississippi Delta region of Arkansas, Louisiana, and Mississippi. SUBJECTS: One thousand six hundred seven adults, both white and African American. MAIN OUTCOME MEASURES: Food security status and diet quality, as defined by adherence to the Healthy Eating Index and Dietary Reference Intakes by determinations from self-reported food intake (1 day intake). STATISTICAL ANALYSES: Regression analysis, t tests, Wald statistic, and beta tests were employed. RESULTS: Food secure adults scored higher on Healthy Eating Index than food insecure adults (P=0.0001), but the regression model showed no differences when multiple factors were included. Food secure individuals consistently achieved higher percentages of the Dietary Reference Intakes (specifically Estimated Average Requirements and Adequate Intakes) than food insecure individuals, with the greatest differences seen for vitamin A (P<0.0001), copper (P=0.0009), and zinc (P=0.0022) and very little difference for vitamins C (P=0.68) and E (P=0.32). Both populations consumed diets extremely low in fiber. CONCLUSIONS: Food insecurity is associated with lower quality diets in this population. It is acknowledged that serious limitations are associated with the use of one 24-hour recall and for comparison between food intake and assessment of food security. These findings still suggest a pressing need for nutrition interventions to improve dietary intake in these at-risk impoverished individuals.

Assessment of the diet quality of US adults in the Lower Mississippi Delta.

BACKGROUND: The Lower Mississippi Delta (LMD) is a region at high risk of nutritionally related diseases. Assessing LMD diet quality is important in policy making, monitoring service outcomes, and designing sustainable research interventions. OBJECTIVE: The purpose was to assess the diet quality of LMD adults by using the Healthy Eating Index (HEI) to 1) identify potential and needed interventions, 2) determine population subgroups needing special attention, and 3) compare regional intakes with national intakes. DESIGN: Data were obtained from a representative cross-sectional telephone survey (n = 1699), Foods of our Delta Study 2000, by using the US Department of Agriculture's multiple-pass 24-h recall methodology and random-digital-assisted dialing with selection of one adult per household. The diet quality of LMD adults was compared with that of white and African American adults in the National Health and Nutrition Examination Survey (NHANES), 1999-2000. RESULTS: Age, race, and income of LMD adults affected overall diet quality. African Americans had lower grain, vegetable, milk, and variety scores than did whites. The consumption of grains and vegetables was associated with lower odds ratios for being overweight. The LMD adults had a lower HEI score than did the adults in NHANES 1999-2000 (60.1 compared with 63.4), and more LMD adults ate a poor diet (24.8% compared with 18.3%). CONCLUSION: Low-income and young-adult households in the LMD are in need of nutrition interventions with an emphasis on increasing grain, fruit, and vegetable intakes. Because socioeconomic factors affect diet quality, a multimodal, longitudinal approach appears needed to improve nutritional health.

The association of child and household food insecurity with childhood overweight status.

CONTEXT: The prevalence of childhood overweight status is increasing. Some have suggested that childhood overweight is associated with food insecurity, defined as limited or uncertain access to enough nutritious food. OBJECTIVES: The purpose of this work was to assess the association of household and child food insecurity with childhood overweight status. METHODS: The National Health and Nutrition Examination Survey 1999-2002 uses a stratified multistaged probability sample and collects a broad array of data from a nationally representative sample of US citizens. All children 3 to 17 years old in this sample are included in these analyses. We measured BMI categorized as at risk for overweight or greater (> or = 85%) or overweight (> or = 95%) and household and child food security/insecurity using the US Food Security Scale. RESULTS: When compared with children from food-secure households, children from food-insecure households were more likely to demonstrate significant associations with being at risk for overweight or greater in the following demographic categories: 12 to 17 years, girls, white, and in households with income < 100% and > 4 times the federal poverty level. Household food insecurity is associated with child overweight status in children aged 12 to 17, girls, and children who live in households with incomes > 4 times the federal poverty level. Child food insecurity demonstrated the same associations with being at risk for overweight or greater, as did household food insecurity, but associations were also seen in 3- to 5-year-old children, boys, and Mexican American children. Child food insecurity is significantly associated with child overweight status for children aged 12 to 17, girls, white children, and children in families with income < or = 100% poverty level. Controlling for ethnicity, gender, age, and family poverty index level, childhood food insecurity is associated with a child being at risk for overweight status or greater, but not overweight status. CONCLUSIONS: Household and child food insecurity are associated with being at risk for overweight and overweight status among many demographic categories of children. Child food insecurity is independently associated with being at risk for overweight status or greater while controlling for important demographic variables. Future longitudinal research is required to determine whether food insecurity is causally related to child overweight status.

Diuretic medication therapy use and low thiamin intake in homebound older adults.

Diuretic therapy (DT) plays a major role in disease management. However, one issue of concern in nutritionally vulnerable elders is that diuretic therapy also increases thiamin excretion, and little attention has been paid to the linkage between DT use and dietary intake of thiamin in this older population. The purpose of this study was to assess the relationship between DT use and dietary intake of thiamin in a randomly recruited sample of 342 homebound older adults. Baseline data, including three 24-hour recalls, were used to identify thiamin intake from food (15% < EAR and 33% < RDA), DT use (49%), and meal pattern (18% not regularly eating breakfast). Independent of sociodemographic and meal pattern variables, DT users (relative to non-users) were at increased odds for dietary thiamin intake < RDA (OR = 2.3) and < EAR (OR = 4.2). Considering the importance of home-delivered meals as a primary source of food assistance to homebound elders and that thiamin deficiency may exacerbate health problems, the results of this study suggest the need to include information on DT use as an integral component of program assessment for the targeting and monitoring of strategies to alleviate the risk for deficiency.

Food safety: emerging trends in foodborne illness surveillance and prevention.

Between 250 and 350 million Americans are estimated to suffer acute gastroenteritis annually, with 25% to 30% thought to be caused by foodborne illnesses. Most vulnerable to foodborne diseases are elderly people, pregnant women, immune-compromised people, and children. While bacterial causes such as Salmonella are widely recognized and monitored as foodborne infections, other important bacterial causes such as Clostridium perfringens , Bacillus cereus , and Staphylococcus aureus are less well known. While the majority of cases of foodborne diseases are of unknown cause, bacteria and viruses are the most likely causative agents. Caliciviridae (Norwalk-like) virus cases are more difficult to identify, but represent the most common cause of known and probably unknown cases. Fresh produce has to be added to the traditional list of foods requiring careful selection and handling to prevent foodborne disease. To assess the disease burden in the United States, morbidity and mortality surveillance activities are done by several networks and systems with collaboration among federal agencies and health departments. Not all important causes are being equally monitored. Critical behaviors by food processors, food retailers, foodservice personnel, and consumers can reduce the risk of foodborne illness episodes. Dietetics professionals can more readily monitor new developments and update knowledge and practice through online resources.