RESUMO
The possibility of voyaging contact between prehistoric Polynesian and Native American populations has long intrigued researchers. Proponents have pointed to the existence of New World crops, such as the sweet potato and bottle gourd, in the Polynesian archaeological record, but nowhere else outside the pre-Columbian Americas1-6, while critics have argued that these botanical dispersals need not have been human mediated7. The Norwegian explorer Thor Heyerdahl controversially suggested that prehistoric South American populations had an important role in the settlement of east Polynesia and particularly of Easter Island (Rapa Nui)2. Several limited molecular genetic studies have reached opposing conclusions, and the possibility continues to be as hotly contested today as it was when first suggested8-12. Here we analyse genome-wide variation in individuals from islands across Polynesia for signs of Native American admixture, analysing 807 individuals from 17 island populations and 15 Pacific coast Native American groups. We find conclusive evidence for prehistoric contact of Polynesian individuals with Native American individuals (around AD 1200) contemporaneous with the settlement of remote Oceania13-15. Our analyses suggest strongly that a single contact event occurred in eastern Polynesia, before the settlement of Rapa Nui, between Polynesian individuals and a Native American group most closely related to the indigenous inhabitants of present-day Colombia.
Assuntos
Fluxo Gênico/genética , Genoma Humano/genética , Migração Humana/história , Indígenas Centro-Americanos/genética , Indígenas Sul-Americanos/genética , Ilhas , Havaiano Nativo ou Outro Ilhéu do Pacífico/genética , América Central/etnologia , Colômbia/etnologia , Europa (Continente)/etnologia , Genética Populacional , História Medieval , Humanos , Polimorfismo de Nucleotídeo Único/genética , Polinésia , América do Sul/etnologia , Fatores de TempoRESUMO
Paleoclimatic evidence indicating a series of droughts in the Yucatan Peninsula during the Terminal Classic period suggests that climate change may have contributed to the disruption or collapse of Classic Maya polities. Although climate change cannot fully account for the multifaceted, political turmoil of the period, it is clear that droughts of strong magnitude could have limited food availability, potentially causing famine, migration, and societal decline. Maize was undoubtedly an important staple food of the ancient Maya, but a complete analysis of other food resources that would have been available during drought remains unresolved. Here, we assess drought resistance of all 497 indigenous food plant species documented in ethnographic, ethnobotanical, and botanical studies as having been used by the lowland Maya and classify the availability of these plant species and their edible components under various drought scenarios. Our analysis indicates availability of 83% of food plant species in short-term drought, but this percentage drops to 22% of food plant species available in moderate drought up to 1 y. During extreme drought, lasting several years, our analysis indicates availability of 11% of food plant species. Our results demonstrate a greater diversity of food sources beyond maize that would have been available to the Maya during climate disruption of the Terminal Classic period than has been previously acknowledged. While drought would have necessitated shifts in dietary patterns, the range of physiological drought responses for the available food plants would have allowed a continuing food supply under all but the most dire conditions.
Assuntos
Dieta , Secas , Plantas Comestíveis , Agricultura , História Antiga , Humanos , Indígenas Centro-AmericanosRESUMO
Genetic studies have consistently indicated a single common origin of Native American groups from Central and South America. However, some morphological studies have suggested a more complex picture, whereby the northeast Asian affinities of present-day Native Americans contrast with a distinctive morphology seen in some of the earliest American skeletons, which share traits with present-day Australasians (indigenous groups in Australia, Melanesia, and island Southeast Asia). Here we analyse genome-wide data to show that some Amazonian Native Americans descend partly from a Native American founding population that carried ancestry more closely related to indigenous Australians, New Guineans and Andaman Islanders than to any present-day Eurasians or Native Americans. This signature is not present to the same extent, or at all, in present-day Northern and Central Americans or in a â¼12,600-year-old Clovis-associated genome, suggesting a more diverse set of founding populations of the Americas than previously accepted.
Assuntos
Indígenas Centro-Americanos/genética , Indígenas Sul-Americanos/genética , Havaiano Nativo ou Outro Ilhéu do Pacífico/genética , Filogenia , Austrália/etnologia , América Central/etnologia , Frequência do Gene/genética , Genoma Humano/genética , Genótipo , Humanos , Indígenas Norte-Americanos/genética , Nova Guiné/etnologia , Filogeografia , América do Sul/etnologiaRESUMO
OBJECTIVE: To analyze the genetic origin, relationships, structure, and admixture in Mayan Native American groups from Guatemala and Mexico based on 15 autosomal short tandem repeats (STRs) loci commonly used in human identification (HID). METHODS: We genotyped 513 unrelated Mayan samples from Guatemala based on 15 STR loci (AmpFlSTR® Identifiler kit). Moreover, we included 4408 genotypes previously reported, as following: Mayas from Guatemala and Mexico (n = 1666) and from Latin American, European, and African (n = 2742) populations. Forensic parameters, genetic distances, admixture, and population structure were assessed. RESULTS: Forensic parameters of the 15 STRs in different Mayan groups from Guatemala were reported. Low (Fst = 0.78%; p = 0.000) and non-significant differentiation (Fst = 1.8%; p = 0.108) were observed in Mayas from Guatemala and Mexico, respectively. The relative homogeneity observed among Mayan groups supported theories of extensive pre-Columbian gene flow and trade throughout the Mayan Empire. The distribution of the three Native American ancestries among these Mayan groups did not support the presumable Guatemalan origin of Tojolabal and Lacandon people (South, Mexico). The nonsignificant differentiation between Ladinos and Mayas suggests a relative panmixia in Guatemala. Mestizos from southeastern Mexico and Guatemala constitute a core of Native American ancestry in Latin America related to the Mayan Empire in Central America. CONCLUSIONS: The higher European admixture and homogeneity in Mexican Mayas of the Yucatan Peninsula suggest more intensive post-Columbian gene flow in this region than in Guatemalan Mayas.
Assuntos
Variação Genética/genética , Indígenas Centro-Americanos/genética , Indígenas Norte-Americanos/genética , Repetições de Microssatélites/genética , Antropologia Física , Genética Forense , Fluxo Gênico/genética , Genética Populacional , Guatemala , Humanos , México , População Branca/genéticaRESUMO
OBJECTIVES: To explore evolutionary hypotheses for the high frequencies of a substitution in the methylenetetrahydrofolate reductase (MTHFR) gene, in Mexican and Central American Indigenous populations. MATERIALS AND METHODS: We obtained allele frequencies for the C677T variant in the MTHFR gene and ecological information for 37 indigenous samples from Mexico and Central America. We calculated Hardy-Weinberg equilibrium and computed Fst statistics. We computed correlations between the samples' allele frequencies and ecological and geochemical variables. RESULTS: Many of the samples have extremely high frequencies of the T allele ( q ¯ = 0.62, median = 0.66). In this region, the frequency of the T allele decreases from Southeast to Northwest and is significantly correlated with longitude, latitude, altitude, and insolation. CONCLUSIONS: The native people of Central America and Mexico evolved high frequencies of an allele which has been shown to produce deleterious clinical effects including neural tube effects, cardiovascular events, and cancer. This allele has a clinal distribution in the region, perhaps associated with solar irradiation. As (Contreras-Cubas et al., 2016) noted, the traditional diet of these populations, which is high in folate, has likely mitigated the negative effect of the allele. It is of primary importance that their rights to their homeland and traditional diets be respected. It is a matter of Public Health to investigate whether this allele is a factor in the current wave of cardiovascular diseases affecting the majority population of this region, since it descends from the Native peoples and the Mediterranean population, which also has high frequencies of the allele.
Assuntos
Frequência do Gene , Genética Populacional , Indígenas Centro-Americanos/genética , Metilenotetra-Hidrofolato Redutase (NADPH2) , Alelos , América Central , Genótipo , Humanos , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , MéxicoRESUMO
BACKGROUND: Colorectal cancer (CRC) is the first cause of cancer deaths among Puerto Ricans. The incidence and mortality of CRC in Puerto Rico continue to be on the rise. The burden of CRC in Puerto Rico is higher than among US Hispanics and is second only to African Americans, thus supporting the importance of studying this CRC health disparity. The genetic background of the Puerto Rican population is a mix of European, African, and Amerindian races, which may account, in part, for the differences observed in the CRC mortality rates among Puerto Ricans. The objective of the study was to assess the role of genetic ancestry in CRC risk and its association with clinicopathological features of CRC tumors in Puerto Ricans. RESULTS: We used a validated panel of 105 ancestry informative markers (AIMs) to estimate genetic ancestry in 406 Puerto Rican CRC cases and 425 Puerto Rican controls. We examined the association of genetic ancestry with CRC risk and tumor clinicopathological characteristics. CONCLUSIONS: The mean ancestry proportions in the study population were 61% European, 21% African, and 18% Amerindian. No association was observed between genetic ancestry and risk of CRC. However, African ancestry was associated with an increased risk of developing rectal tumors (OR = 1.55, 95% CI 1.04-2.31). Additional studies are needed to fully elucidate the role of African ancestry in CRC carcinogenesis.
Assuntos
Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Negro ou Afro-Americano/genética , Idoso , Estudos de Casos e Controles , Feminino , Predisposição Genética para Doença , Hispânico ou Latino/genética , Humanos , Indígenas Centro-Americanos/genética , Masculino , Pessoa de Meia-Idade , Porto Rico , População Branca/genéticaRESUMO
This article briefly traces the history of the colonisation of Guatemala, its impact on the indigenous Mayan communities, the Maya relationship to nature, and the effects of displacement on the psychological and mental health of indigenous communities. It includes three narrative accounts that describe indigenous experiences of mental health and the impact of different mental health interventions in Mayan communities in Guatemala.
Assuntos
Colonialismo , Indígenas Centro-Americanos/etnologia , Transtornos Mentais/etnologia , Saúde Mental/etnologia , Guatemala , Humanos , Transtornos Mentais/terapiaRESUMO
When humans moved from Asia toward the Americas over 18,000 y ago and eventually peopled the New World they encountered a new environment with extreme climate conditions and distinct dietary resources. These environmental and dietary pressures may have led to instances of genetic adaptation with the potential to influence the phenotypic variation in extant Native American populations. An example of such an event is the evolution of the fatty acid desaturases (FADS) genes, which have been claimed to harbor signals of positive selection in Inuit populations due to adaptation to the cold Greenland Arctic climate and to a protein-rich diet. Because there was evidence of intercontinental variation in this genetic region, with indications of positive selection for its variants, we decided to compare the Inuit findings with other Native American data. Here, we use several lines of evidence to show that the signal of FADS-positive selection is not restricted to the Arctic but instead is broadly observed throughout the Americas. The shared signature of selection among populations living in such a diverse range of environments is likely due to a single and strong instance of local adaptation that took place in the common ancestral population before their entrance into the New World. These first Americans peopled the whole continent and spread this adaptive variant across a diverse set of environments.
Assuntos
Ácidos Graxos Dessaturases/genética , Migração Humana/história , Indígenas Centro-Americanos/genética , Indígenas Norte-Americanos/genética , Indígenas Sul-Americanos/genética , Inuíte/genética , Seleção Genética , Povo Asiático/genética , Povo Asiático/história , População Negra/genética , População Negra/história , Mapeamento Cromossômico , Cromossomos Humanos , Genética Populacional , História Antiga , Humanos , Indígenas Centro-Americanos/história , Indígenas Norte-Americanos/história , Indígenas Sul-Americanos/história , Inuíte/história , Polimorfismo de Nucleotídeo Único , População Branca/genética , População Branca/históriaRESUMO
In this study the author address rural Guatemala's poor maternal health and HIV status by integrating an effective evidence-based HIV intervention (SEPA), with local implementing health partners to extend the capacity of comadronas (traditional Mayan birth attendants) to encompass HIV prevention. I employed a multi-method design consisting of a focus group, an interview, and participant observation to identify important factors surrounding comadrona receptivity towards expanding their capacity to HIV prevention. I analyzed data using thematic analysis and identified four categories: Project logistics, HIV knowledge and risk assessment, condom perceptions, and HIV testing perceptions. I affirm comadrona receptivity toward HIV prevention, and that will guide future cultural adaptation and tailoring of SEPA for comadrona training. I will use my results to create a prototype intervention that could be applied to other similarly underserved indigenous communities.
Assuntos
Infecções por HIV/prevenção & controle , Conhecimentos, Atitudes e Prática em Saúde/etnologia , Promoção da Saúde/métodos , Serviços de Saúde Materna/organização & administração , Tocologia , Serviços de Saúde Rural/organização & administração , Adulto , Preservativos , Feminino , Grupos Focais , Guatemala/epidemiologia , Guatemala/etnologia , Infecções por HIV/etnologia , Infecções por HIV/psicologia , Humanos , Indígenas Centro-Americanos , Pessoa de Meia-Idade , Saúde da População Rural , População Rural , Sexo SeguroRESUMO
BACKGROUND: To determine the prevalence of hypertension and investigate sociodemographic correlates in an indigenous Kuna community living on the San Blas islands of Panama. METHODS: Data was collected from adults using a paper-based survey using a cross sectional study design. Blood pressure was measured, and hypertension defined at two cut-points: 130/80 mmHg and 140/90 mmHg. Individuals with undiagnosed hypertension had a blood pressure measurement that indicated hypertension, however, the individual had not been told by a doctor they had hypertension. Whereas individuals with diagnosed hypertension had been told by a healthcare provider that they had hypertension. Univariate tests compared diagnosed and undiagnosed hypertension by sociodemographic categories and logistic regression models tested individual correlates adjusting for all sociodemographic factors. RESULTS: Two hundred and eleven adult indigenous Kuna participated in the study. Overall prevalence of hypertension was 6.2% (95%CI:3.32-10.30) as defined by 140/90 mmHg, and 16.6% (95%CI:11.83-22.31) as defined by 130/80 mmHg. Hypertension was significantly higher in men (31.6, 95% CI:19.90-45.24, compared to 11.0, 95% CI:6.56-17.09). Individuals with low income were 3 times more likely to be hypertensive (OR = 3.13, 95% CI:1.02-9.60) and 3.5 times more likely to have undiagnosed hypertension (OR = 3.42, 95% CI:1.01-11.52); while those with moderate income were 6 times more likely to be hypertensive (OR = 7.37, 95% CI:1.76-30.90) compared to those who were poor. CONCLUSION: The prevalence of diagnosed and undiagnosed hypertension is higher in men and those with higher income. Investigating these factors remains vitally important in helping improve the health of the Kuna through targeted interventions to address chronic disease.
Assuntos
Hipertensão/etnologia , Indígenas Centro-Americanos/estatística & dados numéricos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Humanos , Hipertensão/diagnóstico , Masculino , Pessoa de Meia-Idade , Panamá/epidemiologia , Prevalência , Fatores de Risco , Distribuição por Sexo , Fatores Socioeconômicos , Adulto JovemRESUMO
The Out-of-Africa (OOA) dispersal â¼ 50,000 y ago is characterized by a series of founder events as modern humans expanded into multiple continents. Population genetics theory predicts an increase of mutational load in populations undergoing serial founder effects during range expansions. To test this hypothesis, we have sequenced full genomes and high-coverage exomes from seven geographically divergent human populations from Namibia, Congo, Algeria, Pakistan, Cambodia, Siberia, and Mexico. We find that individual genomes vary modestly in the overall number of predicted deleterious alleles. We show via spatially explicit simulations that the observed distribution of deleterious allele frequencies is consistent with the OOA dispersal, particularly under a model where deleterious mutations are recessive. We conclude that there is a strong signal of purifying selection at conserved genomic positions within Africa, but that many predicted deleterious mutations have evolved as if they were neutral during the expansion out of Africa. Under a model where selection is inversely related to dominance, we show that OOA populations are likely to have a higher mutation load due to increased allele frequencies of nearly neutral variants that are recessive or partially recessive.
Assuntos
Etnicidade/genética , Genoma Humano , Migração Humana , Mutação , África Subsaariana , Alelos , Animais , Povo Asiático/genética , População Negra/genética , Simulação por Computador , Sequência Conservada , Evolução Molecular , Efeito Fundador , Fluxo Gênico , Doenças Genéticas Inatas/genética , Deriva Genética , Genótipo , Comportamento de Retorno ao Território Vital , Humanos , Indígenas Centro-Americanos/genética , Modelos Genéticos , Seleção GenéticaRESUMO
OBJECTIVE: To test the hypothesis that secular changes in body size and age at menarche are related to the demographic and epidemiologic transitions in an indigenous community in Oaxaca, southern Mexico. METHODS: Data were derived from surveys of a Zapotec-speaking community conducted between 1968 and 2000. Segmented linear regressions of height, weight, BMI and recalled age at menarche on year of birth in cohorts of adults born before and after the demographic transition were used to evaluate secular changes. Corresponding comparisons of body size (MANCOVA controlling for age) and age at menarche (status quo, probit analysis) were done for samples of children and adolescents born before and after the epidemiological transition. RESULTS: Height and weight increased in adults born after the demographic transition (mid-1950s), and especially in children and adolescents born after the epidemiological transition (mid-1980s). Age at menarche also decreased significantly in women born after the demographic transition, but at a more rapid estimated rate in adolescents born after the epidemiological transition. Secular gains in body weight were proportional to those for height among children and adolescents, but adults, males more so than females, gained proportionally more weight. CONCLUSIONS: The secular trend in height in adults of both sexes was associated with the decade of the demographic transition in the mid-1950s. Significant secular gains in size attained and age at menarche occurred in children and youth born after the epidemiologic transition which likely reflected improved health and nutritional conditions since the mid-1980s.
Assuntos
Peso Corporal/fisiologia , Indígenas Centro-Americanos/estatística & dados numéricos , Dinâmica Populacional/estatística & dados numéricos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antropologia Física , Índice de Massa Corporal , Criança , Feminino , Humanos , Masculino , Menarca/fisiologia , México/epidemiologia , Pessoa de Meia-Idade , Adulto JovemRESUMO
OBJECTIVES: The aim of this study was to address the hypothesis that Amerindian ancestry is associated with extended longevity in the admixed population of Nicoya, Costa Rica. The Nicoya Peninsula of Costa Rica has been considered a "longevity island," particularly for males. METHODS: We estimated Amerindian ancestry using 464 ancestral informative markers in 20 old Nicoyans aged ≥99 years, and 20 younger Nicoyans (60-65 years). We used logistic regression to estimate odds ratio (OR) and 95% confidence interval (CI) of the association of Amerindian ancestry and longevity. RESULTS: Older Nicoyans had higher Amerindian ancestry compared to younger Nicoyans (43.3% vs 36.0%, P = .04). Each 10% increase of Amerindian ancestry was associated with more than twice the odds of being long-lived (OR = 2.32, 95% CI = 1.03-5.25). CONCLUSIONS AND IMPLICATIONS: To our knowledge, this is the first time that ancestry is implicated as a likely determinant of extended longevity. Amerindian-specific alleles may protect against early mortality. The identification of these protective alleles should be the focus of future studies.
Assuntos
Indígenas Centro-Americanos/estatística & dados numéricos , Longevidade , Idoso , Idoso de 80 Anos ou mais , Costa Rica , Humanos , Pessoa de Meia-IdadeRESUMO
OBJECTIVE: Child undernutrition remains one of the greatest challenges for public health nutrition in rural areas in developing countries. Interventions aiming to increase and conserve agrobiodiversity seem to be promising alternatives to improve child nutrition. However, the existing literature on these interventions is not conclusive about their effectiveness in combating child undernutrition. We tested the hypothesis that 'higher agrobiodiversity is associated with greater dietary diversity and better anthropometric status' in rural Guatemala.Design/Setting/SubjectsIn the summer of 2016, we conducted a cross-sectional study with a sample of 154 children (6-60 months). We conducted dietary recalls and structured interviews, measured children's weight and height, and visited food production systems (Milpas, home gardens, coffee plantations). Crop species richness, nutritional functional diversity, dietary diversity scores and anthropometric status were calculated. RESULTS: Higher food self-sufficiency, nutritional functional diversity and dietary diversity scores were positively correlated with higher crop and animal species richness. Contrarily, remoteness to the local market was negatively correlated with dietary diversity scores. However, higher dietary diversity scores were not correlated with better child anthropometric status. Better child anthropometric status was positively correlated with improved sanitary conditions and maternal education; and negatively correlated with large household size and frequent child morbidity. CONCLUSIONS: Agricultural diversification could diversify diets, increase nutrient availability and improve child anthropometry. However, these interventions need to be accompanied by sanitation improvements, family planning, nutritional education and women's empowerment to strengthen their positive effect on diet and nutrition.
Assuntos
Agricultura , Biodiversidade , Dieta/etnologia , Abastecimento de Alimentos/estatística & dados numéricos , Indígenas Centro-Americanos/estatística & dados numéricos , Antropometria , Fenômenos Fisiológicos da Nutrição Infantil , Pré-Escolar , Estudos Transversais , Inquéritos sobre Dietas , Feminino , Guatemala , Humanos , Lactente , Masculino , Estado Nutricional , Saúde da População Rural/etnologia , População Rural/estatística & dados numéricosRESUMO
OBJECTIVE: To determine the prevalence of and modifiable factors associated with prediabetes in the Comcáac Indians. DESIGN: Cross-sectional study where prediabetes was defined using fasting plasma glucose, 2 h plasma glucose and glycated Hb (HbA1c). Physical, anthropometric and biochemical measurements, medical record, socio-economic, dietary and physical activity information were collected. The modifiable factors associated with prediabetes were assessed using multiple logistic regression. Settings Comcáac Indian communities of Punta Chueca and El Desemboque, Sonora, Mexico. SUBJECTS: Adults (n 227) aged 20 years or older. RESULTS: The sex- and age-adjusted prevalence (95 % CI) of prediabetes was 47·1 (40·8, 53·5) % in the overall population; age-adjusted prevalence was 47·3 (35·6, 59·0) % in men and 46·7 (39·1, 54·3) % in women. The modifiable factors associated with a risk of prediabetes (OR; 95 % CI) were light-intensity physical activity (per 1 h/week increase: 1·04; 1·01, 1·07) and insulin resistance (homeostasis model assessment of insulin resistance score >6·1 v. <4·1: 4·62; 1·37, 15·51). Increased consumption of a traditional dietary pattern based on fish and seafood, low-fat cereals, fruits and vegetables was a protective factor (0·49; 0·31, 0·79). All variables were modelled together and adjusted for age and sex. CONCLUSIONS: The high prediabetes prevalence found in the Comcáac community is alarming because it represents a large number of people who are at risk for type 2 diabetes. The identification of modifiable factors associated with prediabetes that are specific to this population may be useful for designing effective strategies to prevent prediabetes.
Assuntos
Indígenas Centro-Americanos , Estado Pré-Diabético/etnologia , Adulto , Antropometria , Glicemia/metabolismo , Estudos Transversais , Exercício Físico , Feminino , Hemoglobinas Glicadas/metabolismo , Humanos , Masculino , México/epidemiologia , Avaliação Nutricional , Prevalência , Fatores de Risco , Fatores Socioeconômicos , Adulto JovemRESUMO
Our archaeological investigations at Ceibal, a lowland Maya site located in the Pasión region, documented that a formal ceremonial complex was built around 950 B.C. at the onset of the Middle Preclassic period, when ceramics began to be used in the Maya lowlands. Our refined chronology allowed us to trace the subsequent social changes in a resolution that had not been possible before. Many residents of Ceibal appear to have remained relatively mobile during the following centuries, living in ephemeral post-in-ground structures and frequently changing their residential localities. In other parts of the Pasión region, there may have existed more mobile populations who maintained the traditional lifestyle of the preceramic period. Although the emerging elite of Ceibal began to live in a substantial residential complex by 700 B.C., advanced sedentism with durable residences rebuilt in the same locations and burials placed under house floors was not adopted in most residential areas until 500 B.C., and did not become common until 300 B.C. or the Late Preclassic period. During the Middle Preclassic period, substantial formal ceremonial complexes appear to have been built only at a small number of important communities in the Maya lowlands, and groups with different levels of sedentism probably gathered for their constructions and for public rituals held in them. These collaborative activities likely played a central role in socially integrating diverse groups with different lifestyles and, eventually, in developing fully established sedentary communities.
Assuntos
Civilização/história , Comportamento Social , Arqueologia , Arquitetura , América Central , Comportamento Ritualístico , Meio Ambiente , Etnicidade/história , Geografia , Guatemala , História Antiga , Humanos , Indígenas Centro-Americanos/história , Características de ResidênciaRESUMO
Background: Estimated physiologic requirements (PRs) for zinc increase in late pregnancy and early lactation, but the effect on dietary zinc requirements is uncertain.Objective: The aim of this study was to determine changes in daily fractional absorbed zinc and total absorbed zinc (TAZ) from ad libitum diets of differing phytate contents in relation to physiologic zinc requirements during pregnancy and lactation.Methods: This was a prospective observational study of zinc absorption at 8 (phase 1) and 34 (phase 2) wk of gestation and 2 (phase 3) and 6 (phase 4) mo of lactation. Participants were indigenous Guatemalan women of childbearing age whose major food staple was maize and who had been randomly assigned in a larger study to either of 2 ad libitum feeding groups: low-phytate maize (LP; 1.6 mg/g; n = 14) or control maize (C; 7.1 mg/g; n = 8). Total dietary zinc (milligrams per day, TDZ) and phytate (milligrams per day) were determined from duplicate diets and fractional absorption (FAZ) by dual isotope ratio technique (TAZ = TDZ × FAZ). All variables were examined longitudinally and by group and compared with PRs. TAZ values at later phases were compared with phase 1. Measured TAZ was compared with predicted TAZ for nonpregnant, nonlactating (NPNL) women.Results: TAZ was greater in the LP group than in the C group at all phases. All variables increased from phase 1 to phases 2 and 3 and declined at phase 4. TAZ increased by 1.25 mg/d (P = 0.045) in the C group and by 0.81 mg/d (P = 0.058) in the LP group at phase 2. At phase 3, the increases were 2.66 mg/d (P = 0.002) in the C group and 2.28 mg/d (P = 0.0004) in the LP group, compared with a 1.37-mg/d increase in PR. Measured TAZ was greater than predicted values in phases 2-4.Conclusions: Upregulation of zinc absorption in late pregnancy and early lactation matches increases in PRs of pregnant and lactating women, regardless of dietary phytate, which has implications for dietary zinc requirements of pregnant and lactating women.
Assuntos
Dieta , Idade Gestacional , Absorção Intestinal , Lactação , Necessidades Nutricionais , Ácido Fítico/administração & dosagem , Zinco/metabolismo , Adulto , Disponibilidade Biológica , Método Duplo-Cego , Feminino , Guatemala , Humanos , Indígenas Centro-Americanos , Lactação/fisiologia , Estudos Longitudinais , Estado Nutricional , Ácido Fítico/efeitos adversos , Gravidez , Complicações na Gravidez , Terceiro Trimestre da Gravidez , Estudos Prospectivos , Regulação para Cima , Zea mays/química , Zinco/deficiênciaRESUMO
BACKGROUND: Data is needed about barriers to self-collection of Human Papillomavirus (HPV) samples and cytology among low-income, disadvantaged women living in rural areas of lower-income countries as these women are at increased risk of cervical cancer mortality. METHODS: Individual interviews (n = 29), focus groups (n = 7, 5-11 participants) and discussion groups (n = 2, 18-25 participants) were organized with women from three indigenous ethnic groups residing in rural areas in Mexico, after they were provided with free, self-sampled HPV tests. These groups are low-income, underserved by healthcare and have historically been on the receiving end of racism and social exclusion. Descriptive, qualitative content analysis was done, including two cycles of coding. RESULTS: Interview and focus/discussion group data indicate women had limited understanding of HPV's role in cervical cancer etiology. They identified HPV's existence, that cytology detects cervical cancer, the need for regular testing and that cervical cancer is sexually transmitted. Organizational barriers to clinic-based cytology included irregular supplies of disposable speculums, distance to clinics and lack of clear communication by healthcare personnel. Women considered self-collected HPV-testing easy, less embarrassing and less painful than cytology, an opportunity for self-care and most felt they understood how to take a self-sample after a 20-min explanation. Some women feared hurting themselves when taking the self-sample or that they would take the sample incorrectly, which they worried would make the test useless. Attending HPV-testing in groups facilitated use by allowing women to discuss their doubts and fears before doing self-collection of the sample or to ask other women who were the first to do the self-sampling what the experience had been like (whether it hurt and how easy it was). Lack of indoor bathrooms was a barrier to doing HPV self-sampling at home, when those homes were resource-poor (one-room dwellings). CONCLUSIONS: Low-income, indigenous Mexican women residing in rural, underserved areas identified their need for cervical cancer screening but encountered multiple barriers to cytology-based screening. They found a number of advantages of HPV self-sampled tests. Employing self-collected HPV-testing instead of cytology could resolve some but not all gender-related, organizational or technical quality-of-care issues within cervical cancer detection and control programs.
Assuntos
Indígenas Centro-Americanos , Papillomaviridae/isolamento & purificação , Pobreza/economia , População Rural , Autocuidado/economia , Esfregaço Vaginal/economia , Adulto , Técnicas Citológicas , Detecção Precoce de Câncer/economia , Detecção Precoce de Câncer/métodos , Detecção Precoce de Câncer/normas , Feminino , Acessibilidade aos Serviços de Saúde/economia , Acessibilidade aos Serviços de Saúde/normas , Humanos , Indígenas Centro-Americanos/etnologia , Programas de Rastreamento/economia , Programas de Rastreamento/métodos , Programas de Rastreamento/normas , México/etnologia , Grupos Populacionais , Pobreza/etnologia , Pesquisa Qualitativa , Autocuidado/métodos , Autocuidado/normas , Manejo de Espécimes/economia , Manejo de Espécimes/métodos , Manejo de Espécimes/normas , Inquéritos e Questionários/economia , Inquéritos e Questionários/normas , Neoplasias do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/etnologia , Esfregaço Vaginal/métodos , Esfregaço Vaginal/normas , Adulto JovemRESUMO
The present research investigates cultural variation in grounding principles for inferring agency in order to address an important theoretical debate: does cultural diversity in agency concepts reflect an animistic overextension of (universal) folkpsychology, as many have argued, or an alternative theory of folkcommunication based on relational principles? In two experiments, mind perception measures were adapted to assess beliefs concerning the agency of non-animal kinds (plants, abiotic kinds, complex artifacts) among Indigenous Ngöbe adults in Panama and US college students. Agency attributions varied systematically, with Ngöbe ascribing greater agency to non-animal natural kinds and US college participants ascribing greater agency to complex artifacts. Analysis of explanations revealed divergent interpretations of agency as a prototypically human capacity requiring consciousness (US), versus a relational capacity expressed in directed interactions (Ngöbe). Converging measures further illuminated the inferential principles underlying these agency attributions. (1) An experimental relational framing of agency probes facilitated Ngöbe but not US agency attributions. (2) Further analysis showed that three key dimensions of agency attribution (experience, cognition, animacy) are organized differently across cultures. (3) A Bayesian approach to cultural consensus modeling confirmed the presence of two distinct consensus models rather than variations on a single (universal) model. Together, these results indicate that conceptual frameworks for agency differ across US college and Ngöbe communities. We conclude that Ngöbe concepts of agency derive from a distinct theory of folkcommunication based on an ecocentric prototype rather than overextensions of an anthropocentric folkpsychology. These observations suggest that folkpsychology and mind perception represent culture specific frameworks for agency, with significant implications for domain-specificity theory and our understanding of cognitive diversity.