The health of people living in the USA is worse than that of inhabitants in all the other rich nations, as well as some not so rich. There is no privileged American group that can claim the best health in the world. Healthcare, although important, is surpassed by other factors. Health in a country is mostly determined by the amount of economic inequality present and the attention to early life. These issues are determined by political choices. Terms used are described. Readers are challenged to consider the most important lessons on health they have ever encountered

This chapter considers how expanded longevity should impact the law’s response to aging and the needs of older adults. Countries have long responded to old age by creating social welfare policies that use chronological age to target interventions at older adults. This chapter argues that, as life expectancy increases, the use of such age-based criteria will become more problematic: Chronological age will be an increasingly poor predictor of need, and age-based criteria will increasingly result in inequitable distribution of resources. Accordingly, it argues that polities should respond to enhanced longevity not merely by recalibrating age-based criteria to ensure efficient allocation of resources but by reducing reliance of age-based criteria. It concludes by considering whether vulnerability can serve as an alternative targeting mechanism.

There is a substantial difference between the housing that older Americans prefer and the housing that the market supplies. While market failures and seniors’ resource constraints explain part of this mismatch, zoning laws, Medicare and Medicaid reimbursement policies, and health law also loom large. Older Americans strongly prefer to age in place, in home-like environments. This chapter focuses on two types of housing that facilitate that manner of aging: Green House nursing homes and accessory dwelling units. The chapter discusses the substantial benefits for seniors who rely on others for care, and those who can live independently, in these respective kinds of housing. These benefits include substantial health and quality-of-life advantages as well as the ability to maintain connectedness within existing social networks. The chapter further examines the legal impediments to the proliferation of these housing types and the measures that some forward-looking jurisdictions are taking to facilitate their growth.

The conventional three-stage model of human life – from childhood to adulthood to old age – is being upended by social and economic changes that the 100-year life will likely amplify. If law does not adapt to new life patterns, it will worsen existing inequalities. Higher education, family and inheritance, and retirement illustrate how lives are already diverging from assumptions embedded in law about the life cycle while suggesting needed reforms.

Lynda Gratton and Andrew Scott’s prediction that the median lifespan will exceed 100 years for children born today in high-income countries is “science fiction” within the dictionary definition: a “story featuring hypothetical scientific or technological advances.” This chapter argues that for a 100-year life to become the norm within the timeframe that Gratton and Scott envision, we will need to make extraordinary progress over the next several decades in reducing old-age mortality – advances that are qualitatively different from the disease-specific innovations that attract the vast majority of biomedical investment today. To achieve those advances will require not only scientific ingenuity but also legal and political innovation. Patent law – the most familiar tool in the innovation policy toolkit – is ill-fitted for the goal of attaining century-long lives. Instead of relying on private-sector sources, we will likely need governments to commit to moonshot investments in longevity akin to the Apollo project. Yet securing support for those investments will be challenging given the political economy of public funding for biomedical research. Thus the path to a 100-year life will likely require major breakthroughs not only in the laboratory but also in the legislature.

Lifestyle Medicine is an evidence-based medical discipline that emphasises behaviour change to improve overall health, focusing on mental wellbeing, social connections, healthy eating, physical activity, sleep, and minimising harmful behaviours. The approach bridges clinical practice with public health interventions, targeting both individual and population health. It is effective in preventing, treating, and sometimes reversing chronic diseases through lifestyle modification. Clinicians practising Lifestyle Medicine support actions beyond clinical consultations, advocating for healthy environments and policies. The discipline also addresses the challenges of non-communicable diseases and enhances resilience against infectious diseases. It offers an alternative to over-medicalisation, promoting self-care and lifestyle changes alongside traditional medical treatments. The new medical paradigm recognises the modifiability of gene expression and the importance of lifestyle factors in health outcomes. Lifestyle Medicine is increasingly integrated into medical education and healthcare delivery systems. It aligns with the shift towards person-centred care that focuses on patients’ values and goals, contributing to a more holistic approach to health and wellbeing.

Physical inactivity is recognised as a global risk factor for premature mortality and morbidity. Engaging in physical activity and reducing sedentary behaviour significantly improves both mental and physical health at all ages. Lifestyle Medicine emphasises the importance of a person-centred approach to encourage physical activity during consultations. Physical activity guidelines in the UK recommend adults to engage in at least 150 minutes of moderate intensity or 75 minutes of vigorous intensity activity weekly for health benefits. Sedentary behaviour is defined as low-energy expenditure activities while awake and is an independent risk factor for ill health. Clinical and community-based interventions, including brief advice and referral to physical activity programmes, are cost-effective and improve physical activity levels. Various tools exist to assess physical activity levels and fitness in clinical settings, aiding personalised healthcare. Personalised support and health coaching techniques, such as motivational interviewing, effectively promote physical activity. Physical activity reduces the risk of long-term conditions, improves weight management, and has positive effects on metabolism and immune pathways. Supporting increased physical activity as part of Lifestyle Medicine can prevent, treat, and potentially reverse chronic health conditions.

Increase in life expectancy will affect future welfare through changes in the stock of human capital and financial wealth. In projecting these changes it is important to differentiate between the direct demographic effect (a change in the population age structure) and the indirect behavioural change (a change in age-specific economic characteristics). Using a multi-country dynamic (general equilibrium) economic model, this chapter assesses the effects of increasing life expectancy on economic growth and inequality in European countries. The economic model accounts for both the direct effect of changes in the age structure of the population, given the economic characteristics, and the indirect effect of population changes on age-specific economic behaviour in a globalized economy. Projections for the period 2020-2100 show that future life expectancy improvements: (1) will have a negative impact on consumption and output per capita; (2) will negatively affect the accumulation of assets (more so in high-income compared to middle-income European countries due to the more generous pension systems in high-income countries); and (3) will lead to an increase in the intergenerational income inequality due to the fall in asset income at old age. However, it also finds that more generous old-age public transfer systems mitigate the negative impact of life expectancy gains on inequality.

The demography of contemporary hunter-gatherers, farmers and other subsistence populations provides an important lens for studying age patterns of survival and morbidity under non-industrial conditions and lifeways. Although high-quality evidence is sparse, a review suggests robust patterns of human longevity that contradict prior notions of ‘nasty, brutish and short’ lifespans suggested from the palaeodemographic literature. Life expectancy at birth averages about 30 years for hunter-gatherers, and 35 years across all human subsistence groups, a pattern similar to mid-eighteenth-century Europe. Despite short life expectancy, subsistence populations show a modal adult lifespan of about seven decades across a wide range of environments, diets and livelihoods. Over a third of adult life is spent post-reproductive. Infection, violence and accidents are primary causes of death. Post-contact acculturation has mostly improved survivorship, especially in early life, due to access to health care and modern amenities. Loss of land and livelihood, new infections and exploitation, however, have increased mortality and morbidity in some populations. Although the past two centuries have witnessed large gains in lifespan equality and survivorship, the potential for human longevity appears to be a species-typical universal.

This opening chapter provides an overview of the future societal and subsequenl scientific challenges associated with population ageing. More specifically, it emphasizes how the field of biodemography constitutes a relevant framework for future research programmes aiming to address questions of paramount importance regarding both the causes (e.g. evolutionary, mechanistics) and consequences (demographic, medical) of the ageing process. Finally, this chapter details the book contents.

Population aging is a widening demographic phenomenon in many developed countries, with the numbers of survivors above age 90 growing at steady rates. It is the source of many challenges to society. Among key factors to understand population aging, the trajectory of mortality at the highest ages figures at the centre of heated debates across disciplines, from biological to social sciences. This chapter offers a brief overview of mortality modelling above age 90, tracing the history of the most widely used mortality models at these ages, before outlining these models’ mathematical functions as well as their underlying assumptions in the most accessible way possible. Main empirical results obtained from applications of these models throughout decades of research will also be presented, following by a summary of efforts that were made to address the question of possible limits of longevity. This chapter concludes with recommendations for future research. The hope is this material will be useful for anyone who wishes to seize the broad perspective of research on mortality trajectory at highest ages.

This chapter plays an important role in the argument of the book. It shows that there is room in Aristotle’s life for a study of what is common to animals and plants in addition to separate studies of animals and plants. At the same time, it shows that what Aristotle is able, or willing, to say in common for animals and plants is truly limited. By the end of the chapter the reader will see that the Peripatetic study of life is a complex scientific endeavor consisting of at least three components: a study of what is common to animals and plants followed by separate yet coordinated studies of animals and plants. What Aristotle is able, or willing, to say in common for animals and plants is to be found within the boundaries of project of the Parva naturalia.