Teaching developmental biology to drive social change: Pedagogy that challenges biologically deterministic views on phenotypic variation

Discrimination against groups of people based on socially-normed phenotypic variations is commonplace in many societies. The stigmatized phenotypic variations are dependent on specific societal norms but might include features that align with social constructs of race, phenotypic variations that may result in different ability levels, or those that align with social constructs of sex and/or gender identity. Science has contributed to this discrimination through biological essentialism, either by assigning specific undesirable biological characteristics to socially-normed phenotypic groupings, or more recently by assigning a genetic basis for these phenotypic differences. Biological essentialism can promote deterministic views lead to alienation and the persistence of social hierarchies. To overcome this, scientists have a responsibility to create positive changes to decenter practices that contribute to such discrimination. The study of developmental biology straddles the intersection of many biological concepts that have social and political ramifications. This paper outlines a pedagogical approach to create connections between concepts central to developmental biology and broader social issues to which they relate using a biocultural perspective. Specifically, the focus will be on understanding how phenotypes are generated through a combination of biological, environmental and social factors; exploring how deterministic views of biological essentialism contribute to social hierarchies and discrimination (such as racism, sexism, genderism and ableism); and understanding how this discrimination can become embodied through negative chronic and transgenerational biological consequences for stigmatized groups.

The Association of Perceived Stress, Glucocorticoids Receptors, and Corticotropin-Releasing Hormone Gene Expression During Pregnancy

The preterm birth rate and the maternal mortality rate are 1.6 and 2.6 times higher for Black women than for White women, respectively, in the United States. This disproportionate difference in maternal health outcomes is a notable health inequity. The purpose of this study was to evaluate the influence of perceived stress, and glucocorticoid receptors (GR) on histone acetylation (HAT) of the corticotropin-releasing hormone (CRH) gene between non-Hispanic Black and non-Hispanic White women in their second trimester of pregnancy. This study used a cross-sectional design to analyze secondary, deidentified data including peripheral blood monocyte cells, from a prior study. The study sample consisted of 32 non-Hispanic Black women and 73 non-Hispanic White women from the parent study. A four-step hierarchical linear regression analysis was used to analyze the influence of race, perceived stress, and GR on the HAT of the CRH gene. The hierarchical linear regression analysis found that race, perceived stress, and GR significantly predicted the HAT of the CRH. GR explained 41.33% of the variation in HAT CRH of the gene, and age plus race explained an additional 3.56% of the variation in HAT CRH of the gene. The findings of this study suggest that perceived stress and GR among young Black women were associated with higher levels of HAT of the CRH gene, which may contribute to adverse pregnancy outcomes such as preeclampsia and preterm birth. These findings highlight stress-related factors contributing to maternal morbidity, and the need for a comprehensive approach to improving prenatal healthcare.

Origin of the Nuñoa, Perú High Altitude Field Research Site and How It Shaped Our Understanding of Functional Adaptation to High-Altitude Stressors

The study of physical growth and development of Indigenous children from Nuñoa, Perú, in the 1960s showed that growth in body size and skeletal maturation was slow and delayed, while growth in lung volume, measured by forced vital capacity (FVC), was accelerated. Hence, I proposed that the high functional adaptation of high-altitude natives was influenced by developmental processes. To test this hypothesis, my co-investigators and I conducted two sets of major physiological studies at high altitudes. The first studies were conducted in Cusco (3400 m) and Puno (3840 m), Perú. This research showed that the FVC and aerobic capacity of low-altitude Peruvian urban natives acclimatized to high altitudes during the developmental period were similar to those of high-altitude urban natives. In contrast, Peruvian and US participants acclimatized during adulthood did not have the same FVC and aerobic capacity as the high-altitude urban natives. The second set of studies was carried out in the city of La Paz, Bolivia (3752 m), and included Europeans who were acclimatized to high altitudes at different ages. This research confirmed that acclimatization during the developmental period was a major component of the high functional adaptation among high-altitude urban natives. These conclusions have been confirmed by epigenetic studies, which demonstrated that acclimatization to high altitude leads to modifications in the activity of the DNA that facilitate adaptation during the developmental period.

Early Life Stress and Long-Term Survival in the Hamann-Todd Collection

OBJECTIVES

The impact of physiological stress during growth and development on mortality has been a topic of intense interest in bioarchaeology and other disciplines. In this study, we analyze the association between survival and two markers of physiological stress, linear enamel hypoplasia (LEH) and adult stature, in a sample of 296 individuals from the Hamann-Todd Osteological Collection (HTOC).

MATERIALS AND METHODS

The HTOC is among the most well-known osteological collections in the discipline, representing low socioeconomic status individuals from early 20th century Cleveland, Ohio. Ages-at-death and demographic identifiers (sex and socially ascribed race) were known for all individuals in the sample. The association between the skeletal and dental markers of early life stress and survival was evaluated through Kaplan-Meier survival analysis, using log rank tests to analyze the significance of differences in survival among demographic groups.

RESULTS

Significant differences in survival were observed between demographic groups, regardless of LEH status or stature. However, there were no significant differences in survivorship by LEH presence in this sample, despite the expectation that periods of physiological stress during key stages of development contribute to long-term health consequences such as suppressed immune function. For females, shorter statures were associated with a higher probability of survival, while there were no significant differences in survival for males based on stature.

DISCUSSION

It is likely that differences in survival observed in this sample of the HTOC are the consequence of other factors, most likely related to adult environmental quality, as opposed to early life stress.

The Impact of Social Factors on the Benefits of Breastfeeding

INTRODUCTION

Although breastfeeding can protect against a variety of childhood illnesses, rates of breastfeeding are low across the USA and are lowest among ethnic minorities. Here, we aimed to explore the relationships between race, socioeconomic status (SES), and the impacts of breastfeeding on common childhood illnesses.

METHODS

Subjects were recruited from a university-affiliated health system in Southwest Michigan. Data were recorded regarding feeding methods, demographics, and sick visits correlating with five childhood disease states. Insurance status was used as a proxy indicator of SES.

RESULTS

In the overall population, more breastfeeding was associated with a reduced incidence of respiratory illnesses (IRR 0.9991, p = 0.0003) and increased incidence of eczema (IRR 1.0009, p = 0.0297). In white patients, breastfeeding was associated with fewer total diseases (p = 0.004) and respiratory infections (p = 0.0045), while in Black and Hispanic patients, breastfeeding was associated with increased eczema (p = 0.0053 and p < 0.0001, respectively). High-SES white patients had significantly reduced total illnesses (p < 0.0001), ear infections (p = 0.0003), eczema (p < 0.0001), and gastrointestinal illnesses (p = 0.0025). High-SES Black and Hispanic patients had no significant associations with breastfeeding days.

CONCLUSIONS

Breastfeeding appeared protective against total illnesses in high-SES, white populations. Infants of color, regardless of SES, experienced no significant protection. We suggest that the benefits of breastfeeding may not compensate for the detrimental health effects of social inequities. Future breastfeeding research should consider the interactions between social factors and the known health benefits of breastfeeding.

The relationship between cause of death and skeletal markers of physiological stress in the Hamann-Todd collection

OBJECTIVES

Socioeconomic status, past stress events, and other factors may contribute to the cumulative burden of physiological stress, which influences an individual's susceptibility to mortality and cause of death (COD). Here, we explore the association between skeletal evidence of stress and COD in the Hamann-Todd Osteological Collection (HTOC), a predominantly low socioeconomic status sample from the late 19th and early 20th century.

MATERIALS AND METHODS

Skeletal markers of stress including linear enamel hypoplasia (LEH), stature, and antemortem tooth loss (AMTL) were analyzed in 298 individuals in the HTOC. Recorded CODs were grouped into six broad categories and contrasted with stress indicators, ages-at-death, and demographic variables, using various parametric and non-parametric statistical tests.

RESULTS

COD varied by socially ascribed race and sex within the sample. Overall, infectious diseases were more prevalent than degenerative diseases. Individuals that died of infectious diseases had significantly lower ages-at-death compared to degenerative diseases (p < 0.001). There was no association between LEH and COD (χ2 = 4.449, p = 0.487). Stature varied significantly across COD categories for males (F = 2.534, p = 0.032), but not females (F = 1.733, p = 0.132). Controlling for age-at-death, AMTL prevalence was associated with COD (H = 18.53, p = 0.002), with cardiovascular disease being associated with higher prevalence of AMTL.

DISCUSSION

These findings show that some skeletal stress indicators are associated with COD in the HTOC, but the causal pathways of these relationships are not clear. This study adds to growing bodies of literature exploring relationships between past stress events and susceptibility to mortality and long-term consequences of poor living conditions for past individuals.

Racial Disparities and Achievement of the Low Lupus Disease Activity State: A CARRA Registry Study

OBJECTIVE

Differential disease control may contribute to racial disparities in outcomes of childhood-onset systemic lupus erythematosus (cSLE). We evaluated associations of race and individual- or neighborhood-level social determinants of health (SDoH) with achievement of low lupus disease activity state (LLDAS), a clinically relevant treatment target.

METHODS

In this cSLE cohort study using the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Registry, the primary exposure was self-reported race and ethnicity, and collected SDoH included insurance status and area deprivation index (ADI). Outcomes included LLDAS, disease activity, and time-averaged prednisone exposure. Associations among race and ethnicity, SDoH, and disease activity were estimated with multivariable regression models, adjusting for disease-related and demographic factors.

RESULTS

Among 540 children with cSLE, 27% identified as Black, 25% identified as White, 23% identified as Latino/a, 11% identified as Asian, 9% identified as more than one race, and 5% identified as other. More Black children (41%) lived in neighborhoods of highest ADI compared to White children (16%). Black race was associated with lower LLDAS achievement (adjusted odds ratio 0.56, 95% confidence interval [CI] 0.38-0.82) and higher disease activity (adjusted β 0.94, 95% CI 0.11-1.78). The highest ADI was not associated with lower LLDAS achievement on adjustment for renal disease and insurance. However, renal disease was found to be a significant mediator (P = 0.04) of the association between ADI and prednisone exposure.

CONCLUSIONS

Children with cSLE who identified as Black are less likely to achieve LLDAS and have a higher disease activity. Living in areas of higher ADI may relate to renal disease and subsequent prednisone exposure. Strategies to address root causes will be important to design interventions mitigating cSLE racial disparities.

"Rigorous and Systematic Qualitative Data Analysis in Biological Anthropology"

Biological anthropologists have long engaged in qualitative data analysis (QDA), though such work is not always foregrounded. In this article, we discuss the role of rigorous and systematic QDA in biological anthropology and consider how it can be understood and advanced. We first establish what kinds of qualitative data and analysis are used in biological anthropology. We then review the ways QDA has been used in six subfields of biological anthropology: primatology, human biology, paleoanthropology, dental and skeletal biology, bioarchaeology, and anthropological genetics. We follow that with an overview of how to use QDA methods: three simple QDA methods (i.e., word-based analysis, theme analysis, and coding) and three QDA approaches for model-building and model-testing (i.e., content analysis, semantic network analysis, and grounded theory). With this foundation in place, we discuss how QDA can support transformative research in biological anthropology-emphasizing the valuable role of QDA in inductive and community-based research. We discuss how QDA supports transformative research using mixed-methods research designs, participatory action research, and abolition and Black feminist research. Finally, we consider how to close a QDA project, reflecting on the logistics, ethics, and limitations of qualitative data sharing, including how researchers can use the CARE Principles (Collective Benefit, Authority to Control, Responsibility, and Ethics) to support Indigenous data sovereignty.

Childhood psychosocial adjustment and midlife obesity, diabetes and hypertension: prospective study from two birth cohorts

BACKGROUND

Understanding how childhood psychosocial adjustment (CPA) influences later life health outcomes is crucial for developing interventions to mitigate the long-term risk of cardiometabolic diseases (CMDs).

AIMS

To investigate the association between CPA and incident CMDs in mid-life, and the mediating roles of educational attainment, smoking habits and depression during young adulthood.

METHOD

A prospective cohort study utilised data from the 1958 National Child Development Study (NCDS; 1958-2013) and the 1970 British Cohort Study (BCS70; 1970-2018), encompassing 22 012 participants assessed for CPA in childhood, who were subsequently evaluated for educational attainment, smoking habits and depression in young adulthood, followed by assessments for CMDs in mid-life. CPA was assessed using the Bristol Social Adjustment Guides in the NCDS and the Rutter Child Behaviour Scale in the BCS70, with higher scores indicating poorer psychosocial adjustment. The primary outcomes were the mid-life incidences of hypertension, diabetes and obesity.

RESULTS

Compared with children in the lowest tertile for CPA scores, those in the middle tertile had an adjusted odds ratio for hypertension of 0.98 (95% CI 0.90-1.06), whereas those in the highest tertile had an odds ratio of 1.17 (95% CI 1.08-1.26). For diabetes, the corresponding odds ratios (95% CI) were 1.15 (0.98-1.35) and 1.39 (1.19-1.62). For obesity, the corresponding odds ratios (95% CI) were 1.08 (1.00-1.16) and 1.18 (1.09-1.27). These associations were partially mediated by educational attainment (2.4-13.9%) and depression during young adulthood (2.5-14.9%).

CONCLUSIONS

Poorer CPA is correlated with the development of hypertension, diabetes and obesity in mid-life. Interventions aimed at improving CPA may help in reducing the burden of these diseases in later life.

Exploring the Relationship Between Stress, Salivary C-Reactive Protein, and Embodied Physiological Responses in a Nigerian Population

OBJECTIVES

The impacts of stress on inflammation, although hypothesized, have not been thoroughly examined, especially in relation to social and environmental factors and particularly within Black populations. This study aims to explore the biological mechanisms of embodiment linking stress and health to understand physiological changes in the body's response to psychological stress in a Nigerian population. Through a multidisciplinary approach, this study queries the relationship between stress, cortisol, and salivary C-reactive protein (sCRP), a biomarker of inflammation, while also validating the use of sCRP as a potential and accurate stress indicator in the field.

METHODS

In this cross-sectional study, 138 passive drool saliva samples (n female = 89 n male = 49) were collected and assessed for sCRP and cortisol levels in adults. Participants also completed a short demographic survey and, to measure psychological stress, the General Health Questionnaire 12 (GHQ-12). Relationships between sCRP and stress-related variables (i.e., cortisol, GHQ-12, and demographic data) were assessed using Spearman's correlations, simple regression, multivariable linear regression, and exploratory factor analysis.

RESULTS

sCRP levels ranged from 20.57 to 6879.41 pg/mL across all samples, with significant differences between female and male participants. The GHQ-12 was not a significant predictor of sCRP variability. However, socio-demographic factors such as body mass index (BMI), age, self-reported sex, ethnic identity, and cortisol were significant predictors, collectively explaining 24%-27% of the variation in sCRP.

CONCLUSION

Socio-demographic predictors like BMI, age, sex, and particularly ethnic group experience in Nigeria encapsulate aspects of embodied stress, that significantly affect sCRP variability.

Reducing racial and ethnic disparities in cardiovascular outcomes among cancer survivors

PURPOSE OF REVIEW

Analyze current evidence on racial/ethnic disparities in cardiovascular outcomes among cancer survivors, identifying factors and proposing measures to address health inequities.

RECENT FINDINGS

Existing literature indicates that the Black population experiences worse cardiovascular outcomes following the diagnosis of both initial primary cancer and second primary cancer, with a notably higher prevalence of cardio-toxic events, particularly among breast cancer survivors. Contributing socioeconomic factors to these disparities include unfavorable social determinants of health, inadequate insurance coverage, and structural racism within the healthcare system. Additionally, proinflammatory epigenetic modification is hypothesized to be a contributing genetic variation factor. Addressing these disparities requires a multiperspective approach, encompassing efforts to address racial disparities and social determinants of health within the healthcare system, refine healthcare policies and access, and integrate historically stigmatized racial groups into clinical research. Racial and ethnic disparities persist in cardiovascular outcomes among cancer survivors, driven by multifactorial causes, predominantly associated with social determinants of health. Addressing these healthcare inequities is imperative, and timely efforts must be implemented to narrow the existing gap effectively.

Physiological and genomic signatures of war and displacement: A comprehensive literature review and future directions

There are now 108.4 million forcibly displaced people worldwide, many of whom endure adversities that result in trauma, toxic stress, and potentially, altered epigenetic development. This paper provides a comprehensive review of current literature on the biological signatures of war and forced migration among refugee populations. To consolidate evidence and identify key concerns and avenues for future research, we reviewed 36 publications and one article under review, published since 2000, most of which focused on refugees relocated in Europe and the Middle East. This body of work - including cross-sectional, observational, and experimental studies - reveals heterogenous findings regarding human biological responses to war-related adversities and their associations with health outcomes. We conclude with four main observations, regarding why genomic and physiological biomarkers are valuable, what study designs advance understanding of causality and health-promoting interventions, how to prepare for ethical challenges, and why theoretical frameworks and research procedures need more detailed consideration in scientific publications.

Linking Adverse Experiences to Pregnancy and Birth Outcomes: A Life Course Analysis of Racial and Ethnic Disparities Among Low-Income Women

Racial and ethnic disparities in birth outcomes have persisted in the United States for decades, though the causes remain poorly understood. The life course perspective posits that poorer outcomes of Black birthing people stem from heightened exposure to stressors early in life and cumulative exposure to stressors over time. Despite its prominence, this perspective has seldom been investigated empirically. We analyzed longitudinal data gathered from 1319 women in low-income households in Wisconsin who received perinatal home visiting services. Variable- and person-centered analyses were performed to assess whether 15 adverse childhood experiences (ACEs) and 10 adverse adult experiences (AAEs) were associated, alone and in combination, with pregnancy loss, preterm birth, and low birth weight among Hispanic (i.e., Latinx) and non-Hispanic Black and White participants. As expected, there were disparities in preterm birth and low birth weight, and both ACEs and AAEs were linked to poorer pregnancy and birth outcomes. Unexpectedly, bivariate and multivariate analyses showed that the associated effects of ACEs and AAEs were most robust for non-Hispanic White women. A latent class analysis produced four patterns of life course adversity, and multigroup latent class analyses confirmed that, compared to White women, higher-adversity class assignments were associated with less robust effects for Hispanic women, and even less robust effects for Black women. We discuss interpretations of the paradoxical findings, including the possibility that alternative sources of stress such as interpersonal and structural racism may better account for the reproductive disparities that disproportionately affect Black birthing people.

Epigenetic mechanisms linking early-life adversities and mental health

Early-life adversities, whether prenatal or postnatal exposure, have been linked to adverse mental health outcomes later in life increasing the risk of several psychiatric disorders. Research on its neurobiological consequences demonstrated an association between exposure to adversities and persistent alterations in the structure, function, and connectivity of the brain. Consistent evidence supports the idea that regulation of gene expression through epigenetic mechanisms are involved in embedding the impact of early-life experiences in the genome and mediate between social environments and later behavioral phenotypes. In addition, studies from rodent models and humans suggest that these experiences and the acquired risk factors can be transmitted through epigenetic mechanisms to offspring and the following generations potentially contributing to a cycle of disease or disease risk. However, one of the important aspects of epigenetic mechanisms, unlike genetic sequences that are fixed and unchangeable, is that although the epigenetic markings are long-lasting, they are nevertheless potentially reversible. In this review, we summarize our current understanding of the epigenetic mechanisms involved in the mental health consequences derived from early-life exposure to malnutrition, maltreatment and poverty, adversities with huge and pervasive impact on mental health. We also discuss the evidence about transgenerational epigenetic inheritance in mammals and experimental data suggesting that suitable social and pharmacological interventions could reverse adverse epigenetic modifications induced by early-life negative social experiences. In this regard, these studies must be accompanied by efforts to determine the causes that promote these adversities and that result in health inequity in the population.

No Increase in Masked Hypertension Prevalence in Children With Sickle Cell Disease in France

BACKGROUND

An important prevalence (32%-45%) of masked hypertension has been reported in children with sickle cell disease (SCD). Stroke screening is well established using transcranial Doppler (TCD) ultrasound. The objectives of our proof-of-concept study in childhood SCD were to evaluate the prevalence of hypertension and its relationships with cerebral vasculopathy (TCD velocity) and to further evaluate in a subgroup of children the correlations of cardiovascular autonomic nervous system indices with TCD velocity.

METHODS

Ambulatory blood pressure measurement (ABPM) and TCD velocity were obtained in children with SCD and in a restricted sample, cardiac sympathovagal balance using heart rate variability analyses, baroreflex sensitivity, and pulse wave velocity were measured.

RESULTS

In 41 children with SCD (median age 14.0 years, 19 girls, SS/Sβ + thalassemia/SC: 33/2/6), ABPM results showed masked hypertension in 2/41 (5%, 95% confidence interval, 0-11) children, consistent with the prevalence in the general pediatric population, elevated blood pressure (BP) in 4/41 (10%) children, and a lack of a normal nocturnal dip in 19/41 children (46%). Children with increased TCD velocity had lower nocturnal dipping of systolic BP. In the 10 participants with extensive cardiovascular assessment, increased TCD velocity was associated with parasympathetic withdrawal and baroreflex failure. Exaggerated orthostatic pressor response or orthostatic hypertension was observed in 7/10 children that was linked to parasympathetic withdrawal.

CONCLUSIONS

Autonomic nervous system dysfunction, namely loss of parasympathetic modulation, of SCD contributes to increase TCD velocity but is not associated with an increased prevalence of masked hypertension.

CLINICAL TRIALS REGISTRATION

NCT04911049.

Prevalence and risk factors of low birth weight in the United States: An analysis of 2016-2021 data

BACKGROUND

Low birthweight (LBW), infants weighing less than 2,500 g, is a global health concern associated with high infant morbidity and mortality rates. This study investigates LBW prevalence and its relation to maternal sociodemographic characteristics and lifestyle behaviors factors in the United States (US).

METHODS

This analysis used the National Survey of Children's Health (NSCH) data from 2016 to 2021, including n = 225,443 children aged 0-17 years. 18,131 had LBW (<2,500 g), and 2810 had very LBW (VLBW) (<1,500 g). Logistic regression calculated odds ratios (OR) using LBW as the dependent variable, adjusting for various factors.

RESULTS

Between 2016 and 2021 in the United States, LBW prevalence averaged 9.31%, with VLBW at 1.50%. Mothers aged 18-35, White, had the lowest LBW (7.63%) and VLBW (1.17%) rates. Mothers aged ≤18 years, black, had the highest LBW (15.45%) and VLBW infants (4.70%). Maternal age emerged as a significant LBW factor, with an OR of 1.27 for ≤18 and 1.19 for >35. Children in poor health had the highest OR (2.87). Race/ethnicity and other disparities were observed.

CONCLUSION

Our study highlights LBW risk among non-White mothers with specific criteria, emphasizing the need for continued exploration of intersectional targets for change that are exacerbating LBW disparities among marginalized populations which may be artificially attributed to biologic determinants and individual-level risk factors. In-depth analysis of repressive structures at the root of inequalities demand continued research on macro levels of influence. Customized healthcare reform holds the greatest potential to disrupt the patterns contributing to poor health outcomes among LBW children, and will ultimately maximize the reach and effectiveness of health promotion strategies and clinical practices aimed to improve universal maternal and infant health.

Pearl Memorial Lecture. Humans at the extremes: Exploring human adaptation to ecological and social stressors

The field of human biology has long explored how human populations have adapted to extreme environmental circumstances. Yet, it has become increasingly clear that conditions of social stress, poverty, and lifestyle change play equally important roles in shaping human biological variation and health. In this paper, I provide a brief background on the foundational human adaptability research of the International Biological Programme (IBP) from the 1960s, highlighting how its successes and critiques have shaped current research directions in the field. I then discuss and reflect on my own field research that has examined the influence of both environmental and social stresses on human populations living in different ecosystems: the Peruvian Andes, the Siberian arctic, and the Bolivian rainforest. Finally, I consider how the papers in this special issue advance our understanding of human adaptability to extreme conditions and offer directions for future research. Drawing on our field's distinctive evolutionary and biocultural perspectives, human biologists are uniquely positioned to examine how the interplay between social and ecological domains influences the human condition.

The now and future of human biology at the extremes: An introduction to the special issue

OBJECTIVES

A hallmark of the human species is our adaptability to a wide range of different ecologies and ecosystems, including some of the most extreme settings. Human biologists have long studied how humans have successfully (and sometimes unsuccessfully) adapted to such extremes, particularly ecological extremes like environments at lower limits of temperature and high altitude. In this special issue, we revisit traditional definitions and explore new conceptions of work in extreme environments. We argue that our definitions of extremes should change with our changing world, and account for extremes unique to the Anthropocene, including environments of inequality and precarity, pandemic landscapes, climate-impacted settings, obesogenic environments, and the environments of human spaceflight. We also explore the future of work at the extremes and provide some suggested guidelines on how human biologists can continue to build and expand on foundational work in this area.

CONCLUSION

While human biologists have done critical work on groups living in extreme environments, our definitions of humans at the limits continue to change as the world around us also changes. Scholars in this area have a responsibility to re-examine the parameters of extremes to stay at the forefront of scientific exploration and collaboration so human biology, as a discipline, can continue to shape our understanding of adaptability, and thus contribute to the continued thriving of all humans as we endure new climatic, environmental, and societal extremes.

The use of race terms in epigenetics research: considerations moving forward

The field of environmental epigenetics is uniquely suited to investigate biologic mechanisms that have the potential to link stressors to health disparities. However, it is common practice in basic epigenetic research to treat race as a covariable in large data analyses in a way that can perpetuate harmful biases without providing any biologic insight. In this article, we i) propose that epigenetic researchers open a dialogue about how and why race is employed in study designs and think critically about how this might perpetuate harmful biases; ii) call for interdisciplinary conversation and collaboration between epigeneticists and social scientists to promote the collection of more detailed social metrics, particularly institutional and structural metrics such as levels of discrimination that could improve our understanding of individual health outcomes; iii) encourage the development of standards and practices that promote full transparency about data collection methods, particularly with regard to race; and iv) encourage the field of epigenetics to continue to investigate how social structures contribute to biological health disparities, with a particular focus on the influence that structural racism may have in driving these health disparities.

The influence of intergenerational trauma on epigenetics and obesity in Indigenous populations - a scoping review

Background: Research has recently begun to examine the potential intergenerational impacts of trauma on obesity.Objective: This scoping review examines the literature on the interactions between intergenerational trauma, epigenetics, and obesity in Indigenous populations. The review was conducted to identify what is known from the literature about how intergenerational trauma may epigenetically influence obesity in Indigenous populations.Methods: Following the PRISMA-ScR guidelines for scoping reviews, online databases were used to identify studies that included discussion of the four focus topics: trauma, epigenetics, obesity, and Indigeneity. The review resulted in six studies that examined those themes. The focus and findings of the selected studies varied from cultural to biological mechanisms and from discussion regarding trauma, epigenetics, obesity, or Indigeneity, but they support three broad statements. First, they support that obesity has genetic and epigenetic factors. Second, intergenerational trauma is prevalent in Indigenous communities. Finally, intergenerational trauma has cultural and biological influences on obesity.Conclusions: Current literature illustrates that intergenerational trauma has behavioural and epigenetic influences that can lead to increased obesity. This scoping review provides a preliminary map of the current literature and understandings of these topics. This review calls for continued studies regarding the connection between trauma, obesity, and epigenetics in Indigenous communities. Future research is vital for practice and policy surrounding individual and communal healing.

Predicting incident cardiovascular disease among African-American adults: A deep learning approach to evaluate social determinants of health in the Jackson heart study

The present study sought to leverage machine learning approaches to determine whether social determinants of health improve prediction of incident cardiovascular disease (CVD). Participants in the Jackson Heart study with no history of CVD at baseline were followed over a 10-year period to determine first CVD events (i.e., coronary heart disease, stroke, heart failure). Three modeling algorithms (i.e., Deep Neural Network, Random Survival Forest, Penalized Cox Proportional Hazards) were used to evaluate three feature sets (i.e., demographics and standard/biobehavioral CVD risk factors [FS1], FS1 combined with psychosocial and socioeconomic CVD risk factors [FS2], and FS2 combined with environmental features [FS3]) as predictors of 10-year CVD risk. Contrary to hypothesis, overall predictive accuracy did not improve when adding social determinants of health. However, social determinants of health comprised eight of the top 15 predictors of first CVD events. The social determinates of health indicators included four socioeconomic factors (insurance status and types), one psychosocial factor (discrimination burden), and three environmental factors (density of outdoor physical activity resources, including instructional and water activities; modified retail food environment index excluding alcohol; and favorable food stores). Findings suggest that whereas understanding biological determinants may identify who is currently at risk for developing CVD and in need of secondary prevention, understanding upstream social determinants of CVD risk could guide primary prevention efforts by identifying where and how policy and community-level interventions could be targeted to facilitate changes in individual health behaviors.

The indispensability of race in medicine

A movement asking to take race out of medicine is growing in the US. While we agree with the necessity to get rid of flawed assumptions about biological race that pervade automatic race correction in medical algorithms, we urge caution about insisting on a blanket eliminativism about race in medicine. If we look at racism as a fundamental cause, in the sense that this notion has been introduced in epidemiological studies by Bruce Link and Jo Phelan, we must conclude that race is indispensable to consider, investigate, and denounce the health effects of multilevel racism, and cannot be eliminated by addressing more specific risk factors in socially responsible epidemiology and clinical medicine. This does not mean that realism about human races is vindicated. While maintaining that there are no human races, we show how it is that a non-referring concept can nonetheless turn out indispensable for explaining real phenomena.

[Racism and discrimination in the context of health inequalities-a narrative review]

Racism and discrimination as social determinants of health are becoming increasingly recognised in public health research in Germany. Studies show correlations with physical and mental health and even changes at the cellular level. In addition to the adverse health effects of interpersonal and direct discrimination, the relevance of structural and institutional racism for health inequalities has been little explored. This narrative review synthesises and critically discusses relevant and recent research findings and makes recommendations for action in research and practice.Structural and institutional aspects of discrimination and racism are closely linked to health. Systemic discrimination in education, employment, housing and healthcare affects overall, mental and physical health, access to prevention and care, and health behaviour.An analysis of the relationship between living, housing and working conditions and the health situation of people with (and without) a history of migration - in general and in relation to racism and discrimination - seems necessary in order to derive targeted measures for structural prevention, rather than focusing on purely behavioural prevention. In addition to practical interventions (trainings, education, and community-based approaches), the further development of methodological aspects in the field of data collection and analysis is important in order to address this issue comprehensively in research and practice.

Maternal adverse childhood experiences, child mental health, and the mediating effect of maternal depression: A cross-sectional, population-based study in rural, southwestern Uganda

OBJECTIVES

This study aimed to examine the intergenerational effects of maternal adverse childhood experiences (ACEs) and child mental health outcomes in rural Uganda, as well as the potentially mediating role of maternal depression in this pathway. Additionally, we sought to test the extent to which maternal social group membership attenuated the mediating effect of maternal depression on child mental health.

METHODS

Data come from a population-based cohort of families living in the Nyakabare Parish, a rural district in southwestern Uganda. Between 2016 and 2018, mothers completed surveys about childhood adversity, depressive symptoms, social group membership, and their children's mental health. Survey data were analyzed using causal mediation and moderated-mediation analysis.

RESULTS

Among 218 mother-child pairs, 61 mothers (28%) and 47 children (22%) showed symptoms meeting cutoffs for clinically significant psychological distress. In multivariable linear regression models, maternal ACEs had a statistically significant association with severity of child conduct problems, peer problems, and total child difficulty scores. Maternal depression mediated the relationship between maternal ACEs and conduct problems, peer problems, and total difficulty, but this mediating effect was not moderated by maternal group membership.

CONCLUSIONS

Maternal depression may act as a potential mechanism linking maternal childhood adversity with poor child mental health in the next generation. Within a context of elevated rates of psychiatric morbidity, high prevalence of childhood adversity, and limited healthcare and economic infrastructures across Uganda, these results emphasize the prioritization of social services and mental health resources for rural Ugandan families.

The effects of contemporary redlining on the mental health of Black residents

Understanding how structural racism, including institutionalized practices such as redlining, influence persistent inequities in health and neighborhood conditions is still emerging in urban health research. Such research often focuses on historical practices, giving the impression that such practices are a thing of the past. However, mortgage lending bias can be readily detected in contemporary datasets and is an active form of structural racism with implications for health and wellbeing. The objective of the current study was to test for associations among multiple measures of mental health and a measure of contemporary redlining. We linked a redlining index constructed using Home Mortgage Disclosure Act data (2007-2013) to 2021 health data for Black/African American participants in the Study of Active Neighborhoods in Detroit (n = 220 with address data). We used multilevel regression models to examine the relationship between redlining and a suite of mental health outcomes (perceived stress, anxiety, depressive symptoms, and satisfaction with life), accounting for covariates including racial composition of the neighborhood. We considered three mediating factors: perceived neighborhood cohesion, aesthetics, and discrimination. Although all participants lived in redlined neighborhoods compared to the complete Detroit Metropolitan area, participants with very low income, low levels of experienced discrimination, and lower perceptions of neighborhood aesthetics resided in highly redlined neighborhoods (score ≥5). We observed that higher resident-reported neighborhood aesthetics were found in neighborhoods with lower redlining scores and were associated with higher levels of satisfaction with life. We found that lower levels of redlining were significantly associated with higher levels of perceived discrimination, which was significantly, positively associated with anxiety, depressive symptoms, and perceived stress scores. Our findings highlight that contemporary redlining practices may influence the aesthetics of the built environment because these neighborhoods experience less investment, with implications for residents' satisfaction with life. However, areas with lower redlining may be areas where Black/African American people experience increased perceived discrimination.

Genetic Variation and Sensory Perception of a Pediatric Formulation of Ibuprofen: Can a Medicine Taste Too Good for Some?

There is wide variation in how individuals perceive the chemosensory attributes of liquid formulations of ibuprofen, encompassing both adults and children. To understand personal variation in the taste and chemesthesis properties of this medicine, and how to measure it, our first scientific strategy centered on utilizing trained adult panelists, due to the complex and time-consuming psychophysical tasks needed at this initial stage. We conducted a double-blind cohort study in which panelists underwent whole-genome-wide genotyping and psychophysically evaluated an over-the-counter pediatric medicine containing ibuprofen. Associations between sensory phenotypes and genetic variation near/within irritant and taste receptor genes were determined. Panelists who experienced the urge to cough or throat sensations found the medicine less palatable and sweet, and more irritating. Perceptions varied with genetic ancestry; panelists of African genetic ancestry had fewer chemesthetic sensations, rating the medicine sweeter, less irritating, and more palatable than did those of European genetic ancestry. We discovered a novel association between TRPA1 rs11988795 and tingling sensations, independent of ancestry. We also determined for the first time that just tasting the medicine allowed predictions of perceptions after swallowing, simplifying future psychophysical studies on diverse populations of different age groups needed to understand genetic, cultural-dietary, and epigenetic factors that influence individual perceptions of palatability and, in turn, adherence and the risk of accidental ingestion.

Fetal Origins of Health Disparities: Transgenerational Consequences of Racism

Despite advances in perinatal medicine, racial disparity in birth outcomes remains a public health problem in the USA. The underlying mechanisms for this long-standing racial disparity are incompletely understood. This review presents transgenerational risk factors for racial disparities in preterm birth, exploring the impact of interpersonal and structural racism, theoretical models of stress, and biological markers of racial disparities.

The Temporal Politics of Placenta Epigenetics: Bodies, Environments and Time

This article builds on feminist scholarship on new biologies and the body to describe the temporal politics of epigenetic research related to the human placenta. Drawing on interviews with scientists and observations at conferences and in laboratories, we argue that epigenetic research simultaneously positions placenta tissue as a way back into maternal and fetal bodies following birth, as a lens onto children's future well-being, and as a bankable resource for ongoing research. Our findings reflect how developmental models of health have helped recast the placenta as an agential organ that is uniquely responsive to environments during pregnancy and capable of embodying biological evidence about the effects of in utero experiences after birth. We develop the concept of 'recursive embodiment' to describe how placenta epigenetics is reimagining relationships between bodies and environments across developmental, epigenetic, and generational time, and the impacts this has for experiences of pregnancy and responsibilities related to children's health.

Transgenerational effect of Mothers' experiences of discrimination on Black youths' hormone coupling in response to laboratory stress

Exposure to pervasive racial discrimination of Black Americans is transgenerational in that mothers' experiences of discriminatory violence impacts their children. This study explored whether stress-related biomarkers reflect transgenerational racial stress by implementing a "dual activation" framework to probe how adrenal and gonadal hormones underlying adolescent development are co-regulated during a laboratory stressor. Data were collected from 120 Black families in the United States. Children completed the Trier Social Stress Task (TSST-C) and provided 4 saliva samples across 2 days that were assayed for cortisol (C), dehydroepiandrosterone (DHEA), and testosterone (T). Mothers reported their experiences of total discrimination and racial discrimination related to skin color/race. Thirty four percent reported experiences of discrimination and on average 46.7% reported experiences of discrimination due to their race or skin tone. Mothers' experiences of racial discrimination were associated with their child's hormonal reactivity to and recovery from the TSST-C. Youth showed stronger positive hormone coupling between C-T if their mother experienced greater discrimination. Mothers' experiences of racial discrimination influenced both C-T coupling and youths' cortisol recovery from the TSST-C. For youths with high testosterone, cortisol recovery was blunted. Results suggest that associations between racism and hormonal stress response may be transgenerational. Mothers' experiences of discrimination had a profound impact on their children's hormonal co-regulation.

Embedded racism: Inequitable niche construction as a neglected evolutionary process affecting health

Racial health disparities are a pervasive feature of modern experience and structural racism is increasingly recognized as a public health crisis. Yet evolutionary medicine has not adequately addressed the racialization of health and disease, particularly the systematic embedding of social biases in biological processes leading to disparate health outcomes delineated by socially defined race. In contrast to the sheer dominance of medical publications which still assume genetic 'race' and omit mention of its social construction, we present an alternative biological framework of racialized health. We explore the unifying evolutionary-ecological principle of niche construction as it offers critical insights on internal and external biological and behavioral feedback processes environments at every level of the organization. We Integrate insights of niche construction theory in the context of human evolutionary and social history and phenotype-genotype modification, exposing the extent to which racism is an evolutionary mismatch underlying inequitable disparities in disease. We then apply ecological models of niche exclusion and exploitation to institutional and interpersonal racial constructions of population and individual health and demonstrate how discriminatory processes of health and harm apply to evolutionarily relevant disease classes and life-history processes in which socially defined race is poorly understood and evaluated. Ultimately, we call for evolutionary and biomedical scholars to recognize the salience of racism as a pathogenic process biasing health outcomes studied across disciplines and to redress the neglect of focus on research and application related to this crucial issue.

An integrative framework and recommendations for the study of DNA methylation in the context of race and ethnicity

Human social epigenomics research is critical to elucidate the intersection of social and genetic influences underlying racial and ethnic differences in health and development. However, this field faces major challenges in both methodology and interpretation with regard to disentangling confounded social and biological aspects of race and ethnicity. To address these challenges, we discuss how these constructs have been approached in the past and how to move forward in studying DNA methylation (DNAm), one of the best-characterized epigenetic marks in humans, in a responsible and appropriately nuanced manner. We highlight self-reported racial and ethnic identity as the primary measure in this field, and discuss its implications in DNAm research. Racial and ethnic identity reflects the biological embedding of an individual's sociocultural experience and environmental exposures in combination with the underlying genetic architecture of the human population (i.e., genetic ancestry). Our integrative framework demonstrates how to examine DNAm in the context of race and ethnicity, while considering both intrinsic factors-including genetic ancestry-and extrinsic factors-including structural and sociocultural environment and developmental niches-when focusing on early-life experience. We reviewed DNAm research in relation to health disparities given its relevance to race and ethnicity as social constructs. Here, we provide recommendations for the study of DNAm addressing racial and ethnic differences, such as explicitly acknowledging the self-reported nature of racial and ethnic identity, empirically examining the effects of genetic variants and accounting for genetic ancestry, and investigating race-related and culturally regulated environmental exposures and experiences.

Supplementary Information

The online version contains supplementary material available at 10.1007/s44155-023-00039-z.

The spiral of disadvantage: Ethnolinguistic discrimination, acculturative stress and health in Nahua indigenous communities in Mexico

OBJECTIVES

The aim of this study was to test the hypothesis that ethnic and ethnolinguistic discrimination, and Post-Traumatic Stress Disorder (PTSD) related to being Indigenous as well as different aspects of acculturative stress, are associated with poorer health and higher levels of depression among the Nahua Indigenous communities.

MATERIALS AND METHODS

Our quantitative survey was carried out in four different regions inhabited by the Nahua people in Mexico. Self-rated health and depression, the symptoms of PTSD, two facets of acculturative stress and ethnolinguistic discrimination were assessed by questionnaires. The data were analyzed using binary logistic regression models.

RESULTS

The symptoms of PTSD and acculturative stress experienced in the workplace were significantly associated with a higher risk of poor self-rated health, adjusted for various socio-demographic characteristics. Acculturative stress, discouragement of language use, language avoidance and ethnolinguistic discrimination were related to a higher risk of depression and PTSD.

DISCUSSION

Our research implies that ethnic and linguistic discrimination, acculturative stress and the memory of harm linked to being Indigenous reflected in the symptoms of PTSD, are important predictors of poorer health and depression among Nahua groups in Mexico. These adverse effects could be significantly counteracted by effective dealing with stigmatization and discrimination against Indigenous people in Mexico and by replacing strong assimilation pressures with integrational approaches that respect ethnolinguistic diversity and reduce socioeconomic marginalization.

Weathering within war: Somatic health complaints among Vietnamese older adults exposed to bombing and violence as adolescents in the American war

OBJECTIVE

People living in war may experience deteriorating health via weathering (wear and tear) from long-term exposures to psychosocial and environmental stressors. Weathering embodied in somatic health complaints may illuminate the effects of war on health.

METHODS

We investigate whether wartime stress exposures occurring during adolescence and early adulthood affect weathering in late adulthood via linear regression with data from the Vietnamese Health and Aging Study (VHAS). VHAS is a cross-sectional study wherein investigators surveyed 2447 adults aged 60+ in four districts of northern and central Vietnam in 2018. These same individuals ranged in age from seven to 52 in 1965, with most having been in adolescence or early adulthood at the peak of the American war in Vietnam (1965-1975). The sample used for this study (n = 2254) were participants in the first VHAS wave in 2018.

RESULTS

We find older Vietnamese adults exposed to higher-intensity provincial bombing suffer more numerous somatic health complaints (unstandardized β = 0.005, SE = 0.001, p = 0.001). Additionally, greater health complaints emerge among older adults whose most intense bombing exposures were at younger ages of adolescence (< age 15) as compared to those whose peak exposures were in older ages (19-25) (unstandardized β = 0.62 95%, SE = 0.19, p = 0.01).

CONCLUSION

Our findings suggest that age of exposure to armed conflict is a critical determinant of weathering across the life course.

Use of Race in Kidney Function Estimation: Lessons Learned and the Path Toward Health Justice

In 2020, the nephrology community formally interrogated long-standing race-based clinical algorithms used in the field, including the kidney function estimation equations. A comprehensive understanding of the history of kidney function estimation and racial essentialism is necessary to understand underpinnings of the incorporation of a Black race coefficient into prior equations. We provide a review of this history, as well as the considerations used to develop race-free equations that are a guidepost for a more equity-oriented, scientifically rigorous future for kidney function estimation and other clinical algorithms and processes in which race may be embedded as a variable.

Rural Embodiment and Community Health: an Anthropological Case Study on Biocultural Determinants of Tropical Disease Infection and Immune System Development in the USA

Purpose of Review

Biocultural methods are critically important for identifying environmental and socioeconomic factors linked with tropical disease risk and outcomes. For example, embodiment theory refers to the process by which lived experiences impact individual biology. Increased exposure to pathogens, chronic psychosocial stress, and unequal resource access are all outcomes linked with discrimination and poverty. Through lived experiences, race and socioeconomic inequality can literally become embodied-get under the skin and affect physiology-impacting immune responses and contributing to lifelong health disparities. Yet, few studies have investigated tropical disease patterns and associated immune function using embodiment theory to understand lasting physiological impacts associated with living in a high-pathogen environment.

Recent Findings

Here, we use preliminary data drawn from the Rural Embodiment and Community Health (REACH) study to assess whether pathogen exposure and immune stimulation within a sample of children from the Mississippi Delta are associated with household income. We also test whether immune marker levels-assessed with enzyme-linked immunosorbent assays using dried blood spot samples-vary between the REACH sample and a similarly aged nationally representative NHANES sample. Immune marker levels did not differ significantly between REACH participants living below vs. above the federal poverty line, yet immunoglobulin E levels-a marker of macroparasite infection-were higher among REACH study participants compared to the NHANES sample.

Summary

These results may suggest community-level pathogenic exposures (i.e., parasitic infections) are embodied by REACH participants with implications for long-term immune function, potentially resulting in immune aspects that differ from nationally representative samples.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40475-023-00282-z.

Intersectional Approaches to Minority Aging Research

Purpose of Review

Growing racial/ethnic diversity among America's older adults necessitates additional research specifically focused on health and well-being among aging minoritized populations. Although Black and Latinx adults in the USA tend to face worse health outcomes as they age, substantial evidence points to unexpected health patterns (e.g., the race paradox in mental health, the Latino health paradox) that challenge our understanding of health and aging among these populations. In this review, we demonstrate the value of intersectionality theory for clarifying these health patterns and highlight the ways that intersectionality has been applied to minority aging research. To advance the field, we also make several recommendations for incorporating intersectional approaches in future scholarship on minority aging.

Recent Findings

Scholars have applied intersectional approaches to health and aging to unravel how social statuses and social conditions, such as race, ethnicity, gender, nativity, incarceration history, geographic region, and age, produce distinct shared experiences that shape health trajectories through multiple mechanisms.

Summary

We highlight common intersectional approaches used in minority aging research and underscore the value of this perspective for elucidating the complex, and often unexpected, health patterns of aging minoritized populations. We identify several key lessons and propose recommendations to advance scholarship on minority aging.

Psychological legacies of intergenerational trauma under South African apartheid: Prenatal stress predicts greater vulnerability to the psychological impacts of future stress exposure during late adolescence and early adulthood in Soweto, South Africa

BACKGROUND

South Africa's rates of psychiatric morbidity are among the highest in sub-Saharan Africa and are foregrounded by the country's long history of political violence during apartheid. Growing evidence suggests that in utero stress exposure is a potent developmental risk factor for future mental illness risk, yet the extent to which the psychiatric effects of prenatal stress impact the next generation are unknown. We evaluate the intergenerational effects of prenatal stress experienced during apartheid on psychiatric morbidity among children at ages 17-18 and also assess the moderating effects of maternal age, social support, and past household adversity.

METHODS

Participants come from Birth-to-Twenty, a longitudinal birth cohort study in Soweto-Johannesburg, South Africa's largest peri-urban township which was the epicentre of violent repression and resistance during the final years of the apartheid regime. Pregnant women were prospectively enrolled in 1990 and completed questionnaires assessing social experiences, and their children's psychiatric morbidity were assessed at ages 17-18.

RESULTS

Full data were available from 304 mother-child pairs in 2007-8. Maternal prenatal stress in 1990 was not directly associated greater psychiatric morbidity during at ages 17-18. Maternal age and past household adversity moderated the intergenerational mental health effects of prenatal stress such that children born to younger mothers and late adolescent/young adult children experiencing greater household adversity exhibited worse psychiatric morbidity at ages 17-18. Social support did not buffer against the long-term psychiatric impacts of prenatal stress.

CONCLUSIONS

Greater prenatal stress from apartheid predicted adverse psychiatric outcomes among children born to younger mothers and adolescents/young adults who experienced greater concurrent stress. Our findings suggest that prenatal stress may affect adolescent mental health, have stress-sensitising effects, and represent possible intergenerational effects of trauma experienced under apartheid in this sample.

Racism, xenophobia, and discrimination: mapping pathways to health outcomes

Despite being globally pervasive, racism, xenophobia, and discrimination are not universally recognised determinants of health. We challenge widespread beliefs related to the inevitability of increased mortality and morbidity associated with particular ethnicities and minoritised groups. In refuting that racial categories have a genetic basis and acknowledging that socioeconomic factors offer incomplete explanations in understanding these health disparities, we examine the pathways by which discrimination based on caste, ethnicity, Indigeneity, migratory status, race, religion, and skin colour affect health. Discrimination based on these categories, although having many unique historical and cultural contexts, operates in the same way, with overlapping pathways and health effects. We synthesise how such discrimination affects health systems, spatial determination, and communities, and how these processes manifest at the individual level, across the life course, and intergenerationally. We explore how individuals respond to and internalise these complex mechanisms psychologically, behaviourally, and physiologically. The evidence shows that racism, xenophobia, and discrimination affect a range of health outcomes across all ages around the world, and remain embedded within the universal challenges we face, from COVID-19 to the climate emergency.

Toolkit article: Approaches to measuring social inequities in health in human biology research

Across populations, human morbidity and mortality risks generally follow clear gradients, with socially-disadvantaged individuals and groups tending to have higher morbidity and mortality at all life stages relative to those more socially advantaged. Anthropologists specialize in understanding the proximate and ultimate factors that shape variation in human biological functioning and health and are therefore well-situated to explore the relationships between social position and health in diverse ecological and cultural contexts. While human biologists have developed sophisticated methods for assessing health using minimally-invasive methods, at a disciplinary level, we have room for conceptual and methodological improvement in how we frame, measure, and analyze the social inequities that might shape health inequities. This toolkit paper elaborates on some steps human biologists should take to enhance the quality of our research on health inequities. Specifically, we address: (1) how to frame unequal health outcomes (i.e., inequalities vs. disparities vs. inequities) and the importance of identifying our conceptual models of how these inequities emerge; (2) how to measure various axes of social inequities across diverse cultural contexts, and (3) approaches to community collaboration and dissemination. We end by discussing (4) future directions in human biology research of health inequities, including understanding the ultimate causes of sensitivity to social inequities and transitioning from research to action.

Why epigenetics is (not) a biosocial science and why that matters

Epigenetic modifications offer compelling evidence of the environmental etiology of complex diseases. Social and biographical conditions, as well as material exposures, all modulate our biology with consequences for risk predispositions and health conditions. Elucidating these complex biosocial loops is one of the main challenges animating epigenetics. Yet, research on the development of epigenetic biomarkers often pulls in a direction that departs from a view of biological determinants of health embedded in their social and material environment. Taking the example of the epigenetics of cardiovascular diseases, this paper illustrates how common understandings of epigenetic biomarkers strongly lean toward considering them as mere targets for molecular intervention, rather than as correlates of a complex biological and social patterning of disease. This reductionism about biosocial dynamics of disease, we argue, hampers the pursuit of the goals epigenetics has given itself (in cardiology and beyond). If epigenetic mechanisms point to the deep socio-environmental embeddedness of our health, we conclude, future designs and methods of this research may require an improved methodological consideration of a biosocial perspective.

Minimally invasive biomarkers in human and non-human primate evolutionary biology: Tools for understanding variation and adaptation

BACKGROUND

The use of minimally invasive biomarkers (MIBs - physiological biomarkers obtained from minimally invasive sample types) has expanded rapidly in science and medicine over the past several decades. The MIB approach is a methodological strength in the field of human and non-human primate evolutionary biology (HEB). Among humans and our closest relatives, MIBs provide unique opportunities to document phenotypic variation and to operationalize evolutionary hypotheses.

AIMS

This paper overviews the use of MIBs in HEB. Our objectives are to (1) highlight key research topics which successfully implement MIBs, (2) identify promising yet under-investigated areas of MIB application, and (3) discuss current challenges in MIB research, with suggestions for advancing the field.

DISCUSSION AND CONCLUSIONS

A range of MIBs are used to investigate focal topics in HEB, including energetics and life history variation/evolution, developmental plasticity, and social status and dominance relationships. Nonetheless, we identify gaps in existing MIB research on traits such as physical growth and gut function that are central to the field. Several challenges remain for HEB research using MIBs, including the need for additional biomarkers and methods of assessment, robust validations, and approaches that are standardized across labs and research groups. Importantly, researchers must provide better support for adaptation and fitness effects in hypothesis testing (e.g., by obtaining complementary measures of energy expenditure, demonstrating redundancy of function, and performing lifetime/longitudinal analyses). We point to continued progress in the use of MIBs in HEB to better understand the past, present, and future of humans and our closest primate relatives.

Epigenetic citizenship and political claims-making: the ethics of molecularizing structural racism

Epigenetics has generated excitement over its potential to inform health disparities research by capturing the molecular signatures of social experiences. This paper highlights the concerns implied by these expectations of epigenetics research and discusses the possible ramifications of 'molecularizing' the forms of social suffering currently examined in epigenetics studies. Researchers working with oppressed populations-particularly racially marginalized groups-should further anticipate how their results might be interpreted to avoid fueling prejudiced claims of biological essentialism. Introducing the concept of 'epigenetic citizenship,' this paper considers the ways environmentally responsive methylation cues may be used in direct-to-consumer testing, healthcare, and biopolitical interactions. The conclusion addresses the future of social epigenetics research and the utility of an epigenetic citizenship framework.

Preterm and low birthweight birth in the United States: Black midwives speak of causality, prevention, and healing

BACKGROUND

Low birthweight (LBW) and preterm birth (PTB) are more common among Black infants than white infants in the United States. Although multiple hypotheses have been proposed to explain elevated rates of PTB and LBW, the perspectives of Black midwives who serve Black communities are largely missing from the literature.

METHODS

Using semi-structured interviews and focus groups with a purposive sample of midwives (n = 29), we elicited midwives' perceptions of PTB and LBW causation, as well as insights on culturally congruent strategies for prevention. We used consensus coding and reciprocal ethnography to increase the rigor of our analyses.

RESULTS

Midwives identified three intersecting and predisposing root causes: (1) systemic racism; (2) the epigenetic legacy of enslavement; and (3) ongoing cultural loss. In response to these stressors, midwives recommended variants of two additional themes-(4) community building; and (5) culturally centered care-as essential to reversing mortality trends among Black babies.

DISCUSSION

Midwives' perspectives, which are supported by relevant literature, provide critical insights that should inform both research and policy aimed at promoting birth justice in the United States and beyond.

Developmental Origins of Health and Disease, resilience and social justice in the COVID era

The COVID-19 pandemic has shone a spotlight on how health outcomes are unequally distributed among different population groups, with disadvantaged communities and individuals being disproportionality affected in terms of infection, morbidity and mortality, as well as vaccine access. Recently, there has been considerable debate about how social disadvantage and inequality intersect with developmental processes to result in a heightened susceptibility to environmental stressors, economic shocks and large-scale health emergencies. We argue that DOHaD Society members can make important contributions to addressing issues of inequality and improving community resilience in response to COVID-19. In order to do so, it is beneficial to engage with and adopt a social justice framework. We detail how DOHaD can align its research and policy recommendations with a social justice perspective to ensure that we contribute to improving the health of present and future generations in an equitable and socially just way.