The Puerto Rico Young Adults' Stress, Contextual, Behavioral & Cardiometabolic Risk (PR-OUTLOOK) Study: Design and Methods.

The Puerto Rico (PR) Young Adults' Stress, Contextual, Behavioral & Cardiometabolic Risk Study (PR-OUTLOOK) is investigating overall and component-specific cardiovascular health (CVH) and cardiovascular disease (CVD) risk factors in a sample of young (age 18-29) Puerto Rican adults in PR (target n=3,000) and examining relationships between individual-, family/social- and neighborhood-level stress and resilience factors and CVH and CVD risk factors. The study is conducting standardized measurements of CVH and CVD risk factors and demographic, behavioral, psychosocial, neighborhood, and contextual variables and establishing a biorepository of blood, saliva, urine, stool, and hair samples. The assessment methods are aligned with other National Heart, Lung, and Blood Institute funded studies: the Puerto Rico Observational Study of Psychosocial, Environmental, and Chronic Disease Trends (PROSPECT) of adults 30-75 years, the Hispanic Community Health Study/Study of Latinos (HCHS/SOL), the Boston Puerto Rican Health Study (BPRHS), and the Coronary Artery Risk Development in Young Adults (CARDIA). PR-OUTLOOK data and its biorepository will facilitate future longitudinal studies of the temporality of associations between stress and resilient factors and CVH and CVD risk factors among young Puerto Ricans, with remarkable potential for advancing the scientific understanding of these conditions in a high-risk but understudied young population.

Dietary fat modulation of hepatic lipase variant -514 C/T for lipids: a crossover randomized dietary intervention trial in Caribbean Hispanics.

The hepatic lipase (LIPC) locus is a well-established determinant of high-density lipoprotein cholesterol (HDL-C) concentrations, an association that is modified by dietary fat in observational studies. Dietary interventions are lacking. We investigated dietary modulation of LIPC rs1800588 (-514 C/T) for lipids and glucose using a randomized crossover design comparing a high-fat Western diet and a low-fat traditional Hispanic diet in individuals of Caribbean Hispanic descent (n = 42, 4 wk/phase). No significant gene-diet interactions were observed for HDL-C. However, differences in dietary response according to LIPC genotype were observed. In major allele carriers (CC/CT), HDL-C (mmol/l) was higher following the Western diet compared with the Hispanic diet: phase 1 (Western: 1.3 ± 0.03; Hispanic: 1.1 ± 0.04; P = 0.0004); phase 2 (Western: 1.4 ± 0.03; Hispanic: 1.2 ± 0.03; P = 0.0003). In contrast, HDL-C in TT individuals did not differ by diet. Only major allele carriers benefited from the higher-fat diet for HDL-C. Secondarily, we explored dietary fat quality and rs1800588 for HDL-C and triglycerides (TG) in a Boston Puerto Rican Health Study (BPRHS) subset matched for diabetes and obesity status (subset n = 384). In the BPRHS, saturated fat was unfavorably associated with HDL-C and TG in rs1800588 TT carriers. LIPC rs1800588 appears to modify plasma lipids in the context of dietary fat. This new evidence of genetic modulation of dietary responses may inform optimal and personalized dietary fat advice and reinforces the importance of studying genetic markers in diet and cardiometabolic health.

Dietary patterns are associated with bone mineral density in an urban Mexican adult population.

UNLABELLED: Several types of nutrients and foods affect bone mineral density (BMD). However, these nutrients occur together in food groups and dietary patterns, and the overall effects of dietary patterns are not yet well known. INTRODUCTION: We evaluated the associations between dietary patterns and BMD among adults participating in the Health Workers Cohort Study. METHODS: In a cross-sectional analysis, we examined 6915 Mexican adults aged 20-80 years. All participants completed a validated self-administered food frequency questionnaire (FFQ) and had total, hip, and spine BMD measurements assessed by dual-energy X-ray absorptiometry (DXA). The FFQ included 116 foods, which were grouped into 22 categories and entered into a factor analysis to derive dietary patterns. RESULTS: Three dietary patterns emerged-a Prudent, a Refined foods, and a Dairy and fish pattern. After adjustment for potential confounders, those in the highest quintile of the Prudent pattern had lower odds (OR) of low spine BMD (OR = 0.80; 95 % CI 0.68, 0.94; P for trend = 0.031) compared to those in the lowest quintile. In contrast, participants in the highest quintile of the Refined foods pattern had greater odds of low total BMD (OR = 1.74; 95 % CI 1.10, 2.76; P for trend = 0.016) than those in the lowest quintile. Finally, participants in the highest quintile of the Dairy and fish dietary pattern had significantly lower likelihood of having low BMD. CONCLUSION: This study identified specific dietary patterns associated with BMD among a Mexican adult population and highlights the importance of promoting food-based prevention strategies for maintaining bone health.

Latin American Study of Nutrition and Health (ELANS): rationale and study design.

BACKGROUND: Obesity is growing at an alarming rate in Latin America. Lifestyle behaviours such as physical activity and dietary intake have been largely associated with obesity in many countries; however studies that combine nutrition and physical activity assessment in representative samples of Latin American countries are lacking. The aim of this study is to present the design rationale of the Latin American Study of Nutrition and Health/Estudio Latinoamericano de Nutrición y Salud (ELANS) with a particular focus on its quality control procedures and recruitment processes. METHODS/DESIGN: The ELANS is a multicenter cross-sectional nutrition and health surveillance study of a nationally representative sample of urban populations from eight Latin American countries (Argentina, Brazil, Chile, Colombia, Costa Rica, Ecuador, Perú and Venezuela). A standard study protocol was designed to evaluate the nutritional intakes, physical activity levels, and anthropometric measurements of 9000 enrolled participants. The study was based on a complex, multistage sample design and the sample was stratified by gender, age (15 to 65 years old) and socioeconomic level. A small-scale pilot study was performed in each country to test the procedures and tools. DISCUSSION: This study will provide valuable information and a unique dataset regarding Latin America that will enable cross-country comparisons of nutritional statuses that focus on energy and macro- and micronutrient intakes, food patterns, and energy expenditure. TRIAL REGISTRATION: Clinical Trials NCT02226627.

Association between a Healthy Lifestyle Score and inflammatory markers among Puerto Rican adults.

BACKGROUND AND AIMS: The relationship between multiple lifestyle components analyzed in combination and inflammation remains understudied. We aimed to assess the association between a Healthy Lifestyle Score (HLS) that includes adherence to five behavioral components (diet, physical activity and sedentary behaviors, smoking, social support and network, and sleep) and inflammatory markers, as well as the role of the HLS in inflammation among individuals with cardiometabolic conditions, in Puerto Rican adults. METHODS AND RESULTS: In a cross-sectional study of 842 Puerto Ricans adults (aged 45-75 y) living in Boston, MA, the HLS (range = 0-190; maximum indicative of healthiest adherence) was analyzed for association with three inflammatory markers: interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and C-reactive protein (CRP). In multivariable-adjusted models, the HLS was inversely associated with IL-6 (ß ± SE = -0.55 ± 0.13; P < 0.001) and TNF-α (-0.39 ± 0.13; P = 0.004). The dietary and smoking components were associated with both inflammatory markers independently of the other HLS components. Significant inverse associations were observed for each 20-unit increase in HLS and IL-6 and TNF-α for participants with hypertension (n = 600; ß ± SE = -0.58 ± 0.16; -0.46 ± 0.16, respectively) and with overweight/obesity (n = 743; ß ± SE = -0.59 ± 0.13; -0.50 ± 0.14, respectively), but not for those with diabetes (n = 187) or heart disease (n = 192). The HLS was not associated with CRP, after adjustment for potential confounders. CONCLUSION: Higher adherence to multiple lifestyle behaviors was associated with lower concentrations of inflammatory markers. Because low-grade inflammation may precede chronic diseases, following an overall healthy lifestyle may help lower risk of these diseases.

The APOA1/C3/A4/A5 cluster and markers of allostatic load in the Boston Puerto Rican Health Study.

BACKGROUND AND AIMS: The APOA1/C3/A4/A5 cluster encodes key regulators of plasma lipids. Interactions between dietary factors and single nucleotide polymorphisms (SNPs) in the cluster have been reported. Allostatic load, or physiological dysregulation in response to stress, has been implicated in shaping health disparities in ethnic groups. We aimed to determine the association between polymorphisms in the APOA1/C3/A4/A5 cluster with allostatic load parameters, alone, and in interaction with dietary fat intake in Puerto Ricans adults. METHODS AND RESULTS: Data on demographic and anthropometric measures, lifestyle behaviors, and medication use, as well as blood and urine samples for biomarker analysis, were obtained from participants of the Boston Puerto Rican Health Study (n=821, age 45-75 y). The 12 polymorphisms analyzed were not associated with allostatic load parameters. Significant interactions were observed between dietary fat intake and APOA1-75 in association with waist circumference (WC), (P=0.005), APOC3-640 with diastolic blood pressure (DBP), (P=0.003), and APOA4 N147S and APOA5 S19W with systolic blood pressure (SBP), (P=0.001 and P=0.002, respectively). Puerto Ricans homozygous for the common allele of APOA1-75, APOA4 N147S and APOA5 S19W had lower WC and SBP when consuming <31% of total fat from energy, than participants with the minor allele. Participants heterozygous for APOC3-640 had lower DBP at total fat intake ≥31% from energy. CONCLUSION: SNPs in APOA1/C3/A4/A5, as modulated by dietary fat intake, appear to influence allostatic load parameters in Puerto Ricans.

A composite scoring of genotypes discriminates coronary heart disease risk beyond conventional risk factors in the Boston Puerto Rican Health Study.

BACKGROUND AND AIMS: Using a genetic predisposition score (GPS), integrating the additive associations of a set of single nucleotide polymorphisms (SNPs) with CHD, we examined the consequences of the joint presence of a high GPS and conventional risk factors (CRFs). METHODS AND RESULTS: We studied 11 SNPs at eight loci in 197 participants with prior CHD and 524 CHD-free subjects from the Boston Puerto Rican Health Study. Each polymorphism contributed 1 unit (high-risk allele homozygous), 0.5 units (heterozygous) and 0 units (low-risk allele homozygous) to the GPS. Odds ratio (OR) of CHD for those at high risk because of GPS (>5) and simultaneous presence of CRFs were estimated, compared with subjects at low risk, for both measurements. The mean score was higher in participants with prior CHD than those CHD-free (P=0.015), and the OR for CHD with a GPS>5 was 2.90 (P<0.001).The joint presence of a high GPS and each CRF was associated with higher risk of CHD. Compared to participants with high GPS, those with low GPS (

[Use of knee height to correct the body height of elderly Hispanics]. / Uso de la altura de rodilla para corregir la talla de ancianos de origen hispano.

Loss of stature in certain elderly subjects can be attributed to diseases such as osteoporosis, as well as to age and generational effects. In addition, many elders cannot stand straight for accurate measurement. For these cases, total height can be estimated with regression equations based on knee height. The aims of this study were, firstly, to evaluate the applicability of regression equations based on knee height for estimation of stature and, secondly, to document the differences between measured and estimated height in a group of elderly Hispanics with postural problems (n = 166) in comparison with a group of elderly Hispanic without postural problems (n = 270). Using both, estimated and measured height, we also calculated the body mass index (BMI) of both groups of elders. Statistical analyses were done with paired t-tests, within sex and study group. Within the group with postural problems, estimated height was higher than the measured height for both men (p < or = 0.001) and women (p < or = 0.001). There were no significant differences between measured and estimated height in the group without postural problems. Furthermore, in the group with postural problems, BMI values calculated with estimated height were lower than those estimated with the measured height, and these differences were also significant for both men (p < or = 0.001) and women (p < or = 0.001). With the aging of the Latin American population, there is a need for more nutrition and health research among elders. In order to do this we need to develop and use methods and criteria appropriate for each population.

Energy expenditure of stunted and nonstunted boys and girls living in the shantytowns of São Paulo, Brazil.

BACKGROUND: Stunting increases the risk of obesity in developing countries, particularly in girls and women, but the underlying reason is not known. OBJECTIVE: Our objective was to test the hypothesis that stunted children have lower energy expenditure than do nonstunted children, a factor that has predicted an increased risk of obesity in other high-risk populations. DESIGN: A cross-sectional study was conducted in shantytown children from São Paulo, Brazil. Twenty-eight stunted children aged 8-11 y were compared with 30 nonstunted children with similar weight-for-height. Free-living total energy expenditure (TEE) was measured over 7 d by using the doubly labeled water method. In addition, resting energy expenditure (REE) was measured by indirect calorimetry and body composition was measured by dual-energy X-ray absorptiometry. RESULTS: There were no significant associations between stunting and any measured energy expenditure parameter, including REE adjusted for weight (f1.gif" BORDER="0"> +/- SEM: 4575 +/- 95 compared with 4742 +/- 91 kJ/d, in stunted and nonstunted children, respectively) and TEE adjusted for weight (8424 +/- 239 compared with 8009 +/- 221 kJ/d, in stunted and nonstunted children, respectively). In multiple regression models that included fat-free mass and fat mass, girls had significantly lower TEE than did boys (P: < 0.05) but not significantly lower REE (P: = 0.17). CONCLUSIONS: There was no association between stunting and energy expenditure after differences between groups in body size and composition were accounted for. However, the girls had lower TEE than did boys, which may help to explain the particularly high risk of obesity in stunted adolescent girls and women in urban areas of developing countries.

Why are nutritionally stunted children at increased risk of obesity? Studies of metabolic rate and fat oxidation in shantytown children from São Paulo, Brazil.

BACKGROUND: Previous research suggested that nutritionally stunted children may have increased risk of obesity, but little is known about potential underlying mechanisms. OBJECTIVE: We sought to test the hypothesis that stunted children have a low metabolic rate and impaired fat oxidation relative to nonstunted children. DESIGN: The subjects were 58 prepubertal boys and girls aged 8-11 y from the shantytowns of São Paulo, Brazil. Twenty-eight were stunted (height-for-age z score <-1.5) and 30 had similar weight-for-height but normal height (height-for-age z score >-1.5). Parents of children in the 2 groups had equivalent height and body mass index values. Fasting and postprandial energy expenditure, respiratory quotient (RQ), and substrate oxidation were measured with indirect calorimetry in a 3-d resident study in which all food was provided and body composition was measured with dual-energy X-ray absorptiometry. RESULTS: Stunted children had normal resting energy expenditure relative to body composition compared with control children (4559 +/- 90 and 4755 +/- 86 kJ/d, respectively; P: = 0.14) and had normal postprandial thermogenesis (2.4 +/- 0.3% and 2.0 +/- 0.3% of meal load, respectively; P: = 0.42). However, fasting RQ was significantly higher in the stunted group (0.92 +/- 0.009 compared with 0.89 +/- 0.007; P: = 0.04) and consequently, fasting fat oxidation was significantly lower (25 +/- 2% compared with 34 +/- 2% of energy expenditure; P: < 0.01). CONCLUSIONS: Childhood nutritional stunting is associated with impaired fat oxidation, a factor that predicted obesity in other at-risk populations. This finding may help explain recent increases in body fatness and the prevalence of obesity among stunted adults and adolescents in developing countries.

Regulation of energy intake may be impaired in nutritionally stunted children from the shantytowns of São Paulo, Brazil.

We tested the hypothesis that nutritionally stunted children have impaired regulation of energy intake (EI), a factor that could help explain the increased risk of obesity associated with stunting in developing countries. A 3-d residency study was conducted in 56 prepubertal boys and girls aged 8-11 y from the shantytowns of Sao Paulo, Brazil. Twenty-seven of the subjects were stunted and 29 were not stunted; weight-for-height Z-scores were not significantly different between the groups. Parents of the two groups had equivalent heights and body mass indices. Measurements were made of voluntary EI from a self-selection menu, resting energy expenditure (REE) and body composition. In addition, a 753-kJ yogurt supplement was administered at breakfast on one study day (with an equal number of children receiving the supplement on each of the 3 study days) and its effect on daily EI assessed. There was no change in EI over time in either group (P: = 0.957), and no significant difference in EI between stunted and nonstunted children, even though the stunted children weighed 10% less. Energy intake per kilogram body weight was significantly higher in the stunted children (278 +/- 89 (SD), vs. 333 +/- 67 kJ/kg, P: < 0.05) and EI/REE was also significantly higher (1.91 +/- 0.34 vs. 1.68 +/- 0.38, P: < 0.05). However, the relationship between EI and body weight was not significantly influenced by stunting (P: = 0.12). There was no significant effect of the breakfast supplement on daily EI in either group although the absolute difference in EI between supplement and control days was greater in stunted than in nonstunted children (DeltaEI: +460 +/- 1574 vs. -103 +/- 1916 kJ/d, P: = 0.25). These data provide preliminary evidence consistent with the suggestion that stunted children tend to overeat opportunistically, but further studies are required to confirm these results in a larger study.

Type 2 diabetes is prevalent and poorly controlled among Hispanic elders of Caribbean origin.

OBJECTIVES: We estimated prevalence and control of type 2 diabetes in Puerto Rican, Dominican, and non-Hispanic White (NHW) elders and associated them with sociodemographic and health behavior variables and with body mass index (BMI) and waist circumference. METHODS: We used a cross-sectional analysis with a sample of Hispanic elders in Massachusetts and a comparison group of NHWs (1991-1997). The analysis included 379 Puerto Ricans, 113 Dominicans, and 164 NHWs, aged 60 to 96 years, with complete questionnaires and blood samples. RESULTS: Type 2 diabetes was significantly more prevalent among Puerto Ricans (38%) and Dominicans (35%) than among NHWs (23%). Differences remained after covariates were adjusted for. Hispanics with diabetes were approximately 3 times more likely to use insulin than NHWs. Puerto Ricans were 2 times, and Dominicans 3 times, more likely to have glycosylated hemoglobin concentrations of 7% or above than NHWs. BMI and waist circumference were individually associated with diabetes. When included in the model together, waist circumference, but not BMI, remained independently associated with diabetes. CONCLUSIONS: Ethnicity was more strongly associated with diabetes status and control than were socioeconomic or measured health behavior variables, suggesting that genetic or other culturally related factors may explain these differences.

Intake and food sources of macronutrients among older Hispanic adults: association with ethnicity, acculturation, and length of residence in the United States.

OBJECTIVE: To describe the food intake and food sources of macronutrients in diets of older Hispanic adults in the Northeastern United States and to explore relationships between acculturation, years in the United States, and macronutrient intake. DESIGN: Cross-sectional study using a representative sample of older Hispanic adults and a comparison group of non-Hispanic whites. SUBJECTS/SETTING: Hispanic (n = 711) and non-Hispanic white (n = 226) persons, aged 60 years and older, residing in Massachusetts. STATISTICAL ANALYSIS: Macronutrient intakes, collected by 24-hour dietary recall, were compared across ethnic groups by means of the general linear models procedure (with Bonferroni adjustments). Associations between macronutrient intake and predictor variables were tested with Pearson correlations and linear regression. The contribution of foods to total intake of macronutrients was determined by use of a rank procedure. RESULTS: Hispanic elderly subjects consumed significantly less saturated fat and simple sugars and more complex carbohydrates than did non-Hispanic whites. Hispanics residing in the United States for a longer time tended to have macronutrient profiles more similar to those of the non-Hispanic whites. Rice for Hispanic and bread for non-Hispanics were the major contributors of energy. More acculturated Hispanic elders consumed fewer ethnic foods and more foods related to the non-Hispanic-white eating patterns than those less acculturated. APPLICATIONS/CONCLUSIONS: Efforts to promote better diets among Hispanic elders need to emphasize maintenance or adoption of healthful dietary patterns based on ethnic and modern foods that will satisfy their biological, emotional, and social needs. Dietitians and other dietetics practitioners can use the information presented here in studying nutrition-related chronic diseases, in public health planning, and in nutrition education and promotion efforts directed to ethnic-specific, elderly Hispanic groups.

Self-reported prevalence and health correlates of functional limitation among Massachusetts elderly Puerto Ricans, Dominicans, and non-Hispanic white neighborhood comparison group.

BACKGROUND: Limited data suggest that Puerto Ricans experience greater disability than other ethnic groups, but few studies have examined the factors associated with this apparent difference. METHODS: We describe the prevalence of functional limitation and disability in a representative sample of Puerto Rican and Dominican elders in Massachusetts, and in a neighborhood comparison group of non-Hispanic whites (NHWs). We then relate disability scores, based on both prevalence and severity of ADL or IADL limitation, with self-reported history of diagnosed health conditions--adjusting for age, sex, body mass index (BMI; weight kg/height m(2)), income, education, living alone, smoking, and alcohol use. RESULTS: Seventy-five percent of Dominican women and 73% of Puerto Rican women reported difficulty with at least one ADL, compared with 64% of NHW women. Puerto Rican men reported significantly more limitation than did NHW or Dominican men. Conditions significantly associated with at least two disability measures among the NHW included smoking, former heavy alcohol use, arthritis, cataract, respiratory disease, and high BMI, but not stroke, diabetes, history of heart attack, or depression. The patterns for Puerto Ricans differed, with the strongest associations between disability and stroke, arthritis, diabetes, and depression, followed by history of heart attack, high BMI, cataract, poverty status, and respiratory disease. Only arthritis and depression were consistently significantly associated with disability among this smaller sample of Dominican elders. CONCLUSIONS: Functional limitation and disability are more prevalent among Puerto Ricans and among Dominican women than among neighborhood NHWs in Massachusetts. Greater disability is associated with the presence of chronic health conditions, which differ by ethnic group. Additional research is needed to further define the social and health factors that contribute to these ethnic differences.

Adaptation of a food frequency questionnaire to assess diets of Puerto Rican and non-Hispanic adults.

To study issues of diet and health among Hispanic adults living in the northeastern United States, the authors adapted a version of the National Cancer Institute (NCI)/Block food frequency questionnaire. Foods that contributed to nutrient intake of Puerto Rican adults in the Hispanic Health and Nutrition Examination Survey (HHANES) were ranked to identify items to be added to the food list. Portion sizes were compared across HHANES and the Second National Health and Nutrition Examination Survey (NHANES II) to assess the adequacy of the assumed values. Within line items, frequencies of consumption of individual foods were ranked and these data were used to adjust the weighting factors within the database. To test the revised form, 24-hour recalls were collected from 90 elderly Hispanics and 35 elderly non-Hispanic whites. These data were coded into the original and revised food frequency forms and nutrient intake results were compared with recall results by paired t-test, and by Pearson and intraclass correlations. Added foods include plantains, avocado, mango, cassava, empanadas, and custard. Portion sizes differed significantly between HHANES and NHANES II, and were left open-ended. Estimated mean nutrient intakes and correlations with recall data were lower with the original versus the revised form. The authors conclude that the use in minority populations of food frequency questionnaires developed for the general population is likely to result in biased estimates of intake unless modifications are made in the questionnaires.

Preparation effects on tortilla mineral content in Guatemala.

We have previously reported that in Guatemala, the calcium, iron, and zinc contents of tortillas from rural areas are higher that that of tortillas from urban centers. This study examines variation in the calcium, iron, zinc and copper content of tortilla according to the implements used for making tortillas and inquires as to whether preparation effects mediate rural-urban variation in tortilla mineral content. Tortilla samples and information on how the tortillas were prepared were collected from the female heads of a total of 50 households from three rural, two semi-urban and one low income urban community. Samples of lime used for making tortillas were collected from 31 households. To grind masa, a hand mill was found to be used in some rural households whereas a motorized mill predominated in the semi-urban and urban areas. Most women used grinding stones called the "mano y metate" to further refine the texture of the masa. Tortillas prepared with the combined use of the hand mill and "mano y metate" had a significantly (p < 0.05) higher iron content. Use of the "mano y metate" was also associated with a significantly (p < 0.05) higher zinc content. These results suggest that the use of certain grinding implements may mediate rural-urban variation in tortilla iron and zinc content. The cooking surface, pot used for nixtamalization, source of water, and amount of lime used did not significantly account for variation in the content of these minerals.

Preparation effects on tortilla mineral content in Guatemala

We have previously reported that in Guatemala, the calcium, iron, and zinc contents of tortillas from rural areas are higher that that of tortillas from urban centers. This study examines variation in the calcium, iron, zinc and copper content of tortilla according to the implements used for making tortillas and inquires as to whether preparation effects mediate rural-urban variation in tortilla mineral content. Tortilla samples and information on how the tortillas were prepared were collected from the female heads of a total of 50 households from three rural, two semi-urban and one low income urban community. Samples of lime used for making tortillas were collected from 31 households. To grind masa, a hand mill was found to be used in some rural households whereas a motorized mill predominated in the semi-urban and urban areas. Most women used grinding stones called the mano y metate to further refine the texture of the masa. Tortillas prepared with the combined use of the hand mill and mano y metate had a significantly (p < 0.05) higher iron content. Use of the mano y metate was also associated with a significantly (p < 0.05) higher zinc content. These results suggest that the use of certain grinding implements may mediate rural-urban variation in tortilla iron and zinc content. The cooking surface, pot used for nixtamalization, source of water, and amount of lime used did not significantly account for variation in the content of these minerals