The evolution of human disease and the rise of allergy: Epidemiological transitions

Anthropological and sociological perspectives on food allergy

This review explores the anthropological and sociological literature on food allergy and identifies four primary areas of research to date. The first explores the relationality and management of risk, uncertainty and stigma among parents and sufferers of food allergies. The second analyses the influence of intersectionality, specifically the effects of class, gender, race/ethnicity and disability on experiences of food allergy. The third discusses diagnostic difficulties and the impact these have on legitimacy and believability, both in the context of clinician-patient relations and in managing food allergies in public spaces. The fourth explores the ethics and uncertainties in food allergy treatments and how scientific knowledge of emerging treatments is constructed. This body of research illustrates that although an individual disease, food allergy experiences are significantly affected by socio-cultural structures, institutions, ideologies and discourses. The review concludes with four primary recommendations. First, there should be more incorporation of anthropological or sociological methodologies and perspectives into studies of food allergy. Second, studies are needed from more countries exploring lived experience of food allergy. Third, research on food allergy needs to incorporate an analysis of intersectional factors such as gender, class and race/ethnicity, and should explore the experiences of minority populations. Fourth, more research is needed on the interactions between biomedicine and local systems of knowledge, as well as the factors that shape what treatments become available, for whom it becomes available, experiences of treatment and aspects (including biases) that influence patient-clinician interactions.

Shifting Climates, Foods, and Diseases: The Human Microbiome through Evolution

Human evolution has been punctuated by climate anomalies, structuring environments, deadly infections, and altering landscapes. How well humans adapted to these new circumstances had direct effects on fitness and survival. Here, how the gut microbiome could have contributed to human evolutionary success through contributions to host nutritional buffering and infectious disease resistance is reviewed. How changes in human genetics, diet, disease exposure, and social environments almost certainly altered microbial community composition is also explored. Emerging research points to the microbiome as a key player in host responses to environmental change. Therefore, the reciprocal interactions between humans and their microbes are likely to have shaped human patterns of local adaptation throughout our shared evolutionary history. Recent alterations in human lifestyle, however, are altering human microbiomes in unprecedented ways. The consequences of interrupted host-microbe relationships for human adaptive potential in the future are unknown.

The evolution of disease: anthropological perspectives on epidemiologic transitions

BACKGROUND

The model of epidemiologic transitions has served as a guiding framework for understanding relationships between patterns of human health and disease and economic development for the past several decades. However, epidemiologic transition theory is infrequently employed in epidemiology.

OBJECTIVE

Moving beyond Omran's original formulation, we discuss critiques and modifications of the theory of epidemiologic transitions and highlight some of the ways in which incorporating epidemiologic transition theory can benefit theory and practice in epidemiology.

DESIGN

We focus on two broad contemporary trends in human health that epidemiologic transition theory is useful for conceptualizing: the increased incidence of chronic inflammatory diseases (CIDs), such as allergic and autoimmune diseases, and the emergence and reemergence of infectious disease.

RESULTS

Situating these trends within epidemiologic transition theory, we explain the rise in CIDs with the hygiene hypothesis and the rise in emerging and reemerging infections with the concept of a third epidemiologic transition.

CONCLUSIONS

Contextualizing these trends within epidemiologic transition theory reveals implications for clinical practice, global health policies, and future research within epidemiology.

The changing disease-scape in the third epidemiological transition

The epidemiological transition model describes the changing relationship between humans and their diseases. The first transition occurred with the shift to agriculture about 10,000 YBP, resulting in a pattern of infectious and nutritional diseases still evident today. In the last two centuries, some populations have undergone a second transition, characterized by a decline in infectious disease and rise in degenerative disease. We are now in the throes of a third epidemiological transition, in which a resurgence of familiar infections is accompanied by an array of novel diseases, all of which have the potential to spread rapidly due to globalization.

Evolutionary, historical and political economic perspectives on health and disease

The origin and rise of social inequalities that are a feature of the post-Neolithic society play a major role in the pattern of disease in prehistoric and contemporary populations. We use the concept of epidemiological transition to understand changing ecological relationships between humans, pathogens and other disease insults. With the Paleolithic period as a baseline, we begin with ecological and social relationships that minimized the impact of infectious disease. Paleolithic populations would have retained many of the pathogens that they shared with their primate ancestors and would have been exposed to zoonoses that they picked up as they adapted to a foraging existence. The sparse mobile populations would have precluded the existence of endemic infectious disease. About 10,000 years ago, the shift to an agricultural subsistence economy created the first epidemiological transition, marked by the emergence of infections, a pattern that has continued to the present. Beginning about a century ago, some populations have undergone a second epidemiological transition in which public health measures, improved nutrition and medicine resulted in declines in infectious disease and a rise in non-infectious, chronic and degenerative diseases. Human populations are entering the third epidemiological transition in which there is a reemergence of infectious diseases previously thought to be under control, and the emergence of novel diseases. Many of the emerging and reemerging pathogens are antibiotic resistant and some are multi-antibiotic resistant. Inequality continues to widen within and between societies, accelerating the spread of emerging and reemerging diseases.