Taking Political Determinants of Planetary Health Seriously: Expanding from P4 to P5 Medicine

Perspective

Predictive, Personalized, Preventive, and Participatory (P4) medicine rose to prominence over the past two decades (Weston and Hood, 2004) and has been mobilized around the world (Özdemir, 2018). P4 medicine is assembled by several conceptual threads that run through and connect its four pillars. Chief among these is the concept of theranostics, the fusion of therapeutics with diagnostics, which aim to individually tailor health interventions such as drugs, nutrition, vaccines, and radiotherapy, among others. P4 medicine targets not only personalized/precision treatments for diseases but also prevention and advancement of health. Despite its focus on the individual, P4 medicine is in close conceptual proximity to public health by virtue of its attentiveness to health and preventive medicine.

P4 medicine is a type of “variability science.” It unpacks the mechanisms of between-person and between-population differences in health outcomes, and subsequently individually tailors therapeutic/preventive interventions. The P4 medicine approach (1) increases the resolution of diagnostics from the “average patient” to an individual patient, (2) creates a new category of diagnostics (theranostics noted above) to identify the right drug, for the right patient, at the right dose, and at the right time, and thus (3) opens up new creative spaces to account for molecular, phenotypic, and therapeutic heterogeneity in health and disease. Such highly granular attention to understand health, disease, the person, and the population at large facilitates discovery of novel drugs and interventions that display optimal efficacy and safety in a certain subgroup of patients who share a unique molecular and environmental signature. Seen in this light, P4 medicine empowers diagnostics and therapeutics innovation, another conceptual thread that usefully connects with public health.

The idea of individually tailored health interventions embedded in P4 medicine is not new, however. While diagnosticians in ancient times lacked our contemporary multiomics technologies, astute clinical observations allowed for differentiation of health and illness, and forecasts of patient outcomes. Urine examination was used to diagnose diseases by Sumerians and Babylonians as early as 4000 BCE, and by Hippocrates of Cos (circa 460–377 BC) (Magiorkinis and Diamantis, 2015). In the case of responses to nutrition, Pythagoras of Samos (circa 570–495 BC) noted that fava bean consumption carries a risk of a life-threatening adverse reaction, favism, in some, but not all, individuals. The hereditary deficiency of glucose-6-phosphate dehydrogenase was later identified as the mechanism of favism. Building on advances in biochemical genetics in the first half of the 20th century, Werner Kalow in Toronto wrote the first book on pharmacogenetics, the study of gene-by-drug interactions in 1962, thus expanding the field of human genetics from phenotypes of health and disease to drug-related phenotypes (Kalow, 1962).

More recently, the idea of personalized medicine has been transformed to precision medicine with the launch of the Precision Medicine Initiative in 2015 by President Obama to move beyond “one-size-fits-all” treatments. The line of thought on individually tailored health interventions thus displayed spatial and temporal variations, taking on different names and associating with various technologies. On the other hand, the significant influences of science cultures and political determinants of health on P4 medicine have been relatively overlooked.

Clinical and Political Are Co-Constitutive

Knowledge production in the clinic and science (Feyerabend, 2011; Foucault, 2003) is inherently political, as underlined in an editorial in Science (Thorp, 2020). By politics, I refer to a broad range of value-laden activities and power asymmetries that impact on sharing of common resources in science and society. Politics is ubiquitously present well beyond parliament or congress, for example, on the street, at the workplace, in economics and the marketplace, the university, at home in the garden, the kitchen and the bedroom, among neighbors, on public transport, and whenever two or more persons are sharing a resource. Since the age of Enlightenment in the 17th century, science and economics were, however, disarticulated from politics along the lines of classical liberalism, and with an ahistorical and depoliticized approach that continues into the 21st century (Duggan, 2003; Feyerabend, 2011; Özdemir, 2019a; Reinhart, 2023). The consequence of this disarticulation of science and economics from politics is that science is falsely presented as an invariably technocratic and objective field. This brings about an impunity to science, scientists, and other innovation actors despite the ever-present political determinants in health, science, and P4 medicine (Feyerabend, 2011).

In the pursuit of P4 medicine, the political determinants of health—that health is not “just health care” but is inseparable from, and shaped and coproduced by, structural and systemic factors such as class and decolonial struggles, race, gender, sexuality, immigration, xenophobia, ableism, market fundamentalism, anthropocentrism, and other power asymmetries embedded in medical and scientific practice—have been largely overlooked. Moreover, there is no “single issue politics” (Duggan, 2003). Many of these structural factors work intersectionally in producing the attendant power asymmetries and social injustices in science and P4 medicine. Without acknowledging and critically unpacking the structural factors, the causes of causes, the liberatory struggles for social justice, and responsible innovation in science, engineering, and P4 medicine cannot materialize.

Structural and political determinants of health, and by extension, of P4 medicine, shape not only what is visible, legitimate, and glorified in the limelight of science and the clinic but also the scientifically robust innovations that are silenced and erased because they contest the status quo power regimes in science and society.

Since the launch of the Human Genome Project in the last decade of the 20th century, there have been attempts to address the politics of science, technology, and innovation, and more recently, of P4 medicine, by asking downstream, instrumental, and often ahistorical and depoliticized questions such as “which social issues emerge from a new technology?” (Özdemir, 2019a; Özdemir, 2019b). On the other hand, upstream, critically grounded, and epistemological questions such as “who should be framing the P4 medicine science and technology policy, and why?,” have been largely relegated to a subsidiary position (Özdemir, 2019b; Özdemir and Springer, 2022). In the aftermath of the Covid-19 pandemic, it is clearer that political determinants of health are the causes-of-causes for disease and health (Kickbusch, 2015), and essential for efficient, ethical, and socially just responses to the planetary health challenges in the 21st century (Hong, 2022). Hence, I propose that we need P5 medicine, by adding a fifth P, political determinants of planetary health, to P4 medicine.

The new “P” proposed herein can engage not only with the instrumental aspects of P4 medicine research and clinical implementation but also with the structural and systemic issues that are integral parts of the politics of P4 medicine and yet have been largely overlooked. For example, the legacies of colonialism, and the unequal relationships in trade, labor, provision, and production of materials among nation-states and between the Global South and the Global North (Wallerstein, 2004) continue to contribute to social injustices in contemporary science and medicine (Fanon, 1963; Reinhart, 2021; Said, 1978). The World-Systems Theory developed by Immanuel Wallerstein (Wallerstein, 2004) takes to task these macrosociological issues with colonial and historical origins impacting on planetary economics, labor, and development, and by extension, science and medicine in the contemporary moment. In addition to the World-Systems Theory, a decolonial politics of health is necessary and timely for P5 medicine. By asking the question, “how might we build a decolonial politics of care?” in the aftermath of the Covid-19 pandemic, Eric Reinhart usefully brings into conversation the political theorist and psychiatrist Frantz Fanon's scholarship on decolonization (Fanon, 1963) that is relevant to political determinants of planetary health (see, for a review, Reinhart, 2023; Reinhart, 2021).

Conclusions and Outlook

Since the 17th century and the age of Enlightenment, modernity's grandest project, science, has been treated as apolitical and ahistorical and as though scientific practice is enacted by value-free machines. The analysis in this article proposes that P4 medicine will be well served and buttressed by addition of a “fifth P,” political determinants of planetary health. This would bode well for the Science, Technology, Engineering, and Mathematics fields and make P4 medicine robust, sustainable, responsible, and accountable.

A psychocognitive aspect is another conceivable “fifth P” that was proposed as an addition to the P4 medicine approach to the science and art of therapeutics and diagnostics (Gorini and Pravottoni, 2011). Indeed, there could be many “fifth P” dimensions and other noteworthy, for example, “sixth P” additions to P4 medicine. I suggest that placing the political determinants as a key knowledge domain is essential for at least two reasons. First, the politics of knowledge production impacts all aspects of science and medicine including and beyond P4 medicine. Second, politics has been neglected in knowledge production, science, medicine, and economics for a long time, owing to disarticulation of politics in the way the scientific enterprise has been conceived and enacted upon since the age of Enlightenment and the 17th century (Duggan, 2003; Özdemir, 2019b; Özdemir, 2019c). P5 medicine stands to fill this gap and make contributions in planetary health and society in ways that are democratic, equitable, and historically and critically informed.