Paris:  from capital of early death during the Belle Époque (1871-1914) to a longevity champion today 

Paris was once marked by high mortality. In the late 19th century, the French capital lagged significantly behind the rest of France in life expectancy. Today, it ranks among the places in the world where people live the longest. Florian Bonnet, France Meslé, Catalina Torres and Lionel Kesztenbaum dive into the city’s historical health records to reveal the drivers of this transformation.

How long can one expect to live? Behind this seemingly simple question lies one of the most important indicators of a country’s socio-economic development (Olshansky et al 2024). Life expectancy at birth reflects more than the average length of life: it encapsulates a population’s health status, living conditions and social inequalities in longevity.

In 2024, France ranked among the countries with the highest life expectancy worldwide, reaching 80 years for males and 85 years and 9 months for females, according to INSEE. But national averages can hide regional differences. In Paris, for example, life expectancy was 82 years for males and 86 years and 9 months for females, two years and one year higher, respectively, than the national averages.

Paris hasn’t always been a haven for healthy life, however. Just 150 years ago, life in the French capital was dramatically shorter. Figure 1 charts life expectancy at age one (excluding infant mortality, which was very high and poorly recorded in Paris at the time) between 1872 and 2019 for France as a whole (in black) and for Paris (in red). In 1872, a Parisian boy who reached his first birthday could expect to live another 43 years and 6 months, and a Parisian girl, 44 years and 10 months.

Less well known is the fact that life expectancy in Paris remained lower than the national average for much of modern history. At the end of the 19th century, the gap reached 10 years for males and 8 years for females, a phenomenon known in the literature as the “urban penalty”, reflecting the deadly combination of crowding, poor sanitation, and high exposure to infectious diseases (Woods 2003). It wasn’t until the early 1990s for females and the 2000s for males that Paris overtook the rest of France.

Reconstructing a century of urban mortality

In a recent study, we sought to understand how Paris transitioned from a capital of early death to one of the world’s longevity leaders (Bonnet et al 2025). The data to answer this question existed, but were scattered across municipal archives. Moreover, cause-of-death statistics were difficult to use due to changes in classifications and the high cost of collection.

For this study, we compiled and harmonized a new dataset of cause-specific mortality in Paris between 1890 and 1949. This unprecedented resource – now publicly available (https://osf.io/wcyft/) – enabled us to trace the key drivers behind the city’s rapid improvements in life expectancy during the first half of the 20th century (the period between the two red vertical lines in Figure 1), when its trajectory began to converge with the rest of France. To analyse the evolution of social and spatial inequalities in mortality, we also collected data for selected infectious diseases at the district level (across all 80 neighbourhoods of present-day Paris).

Nearly 25 years gained in life expectancy, 80% due to infectious disease decline

Between 1890 and 1950, life expectancy at age one in Paris increased by nearly 25 years. What drove this remarkable progress? Figure 2 breaks down the gain by major causes of death for both males and females. Red colours represent infectious diseases – tuberculosis, diphtheria, measles, bronchitis, and pneumonia – which were the leading causes of death in Paris during the Belle Époque.

The conclusion is striking: infectious disease decline alone accounts for almost 20 years, or 80% of the total life expectancy gain (25 years). Tuberculosis was the primary driver. Its rapid decline after World War I contributed 8 years of life expectancy gain for males and 6 for females. Respiratory infections (bronchitis and pneumonia) added another 5 years, while diphtheria (particularly deadly among children) declined sharply in the 1890s thanks to improvements in drinking water infrastructure, contributing around 2.5 years.

Cardiovascular diseases and cancers, on the other hand, played only a marginal role before 1950. Their effects appeared later and, in the case of cancer (especially among males), even slightly slowed progress in life expectancy. Pregnancy-related mortality among women had a limited impact.

The evolution of social inequalities in mortality 

The battle against tuberculosis reveals another critical dimension: stark social and spatial disparities in mortality. Using the reconstructed cause-of-death data across Paris’s 80 districts, we mapped mortality rates from tuberculosis around 1900. These rates were calculated as the number of deaths per 100,000 inhabitants.

Figure 3 highlights massive inequalities within the city. The highest rates, often exceeding 400 deaths per 100,000, were concentrated in the east and south of Paris. The three most affected neighbourhoods were Saint-Merri (nearly 900), Plaisance (850), and Belleville (just under 800). In contrast, the western neighbourhoods, such as Champs-Élysées, Europe, and Chaussée-d’Antin, had rates closer to 100.

These spatial differences directly reflected the social inequalities of the time. Using early 20th-century rent data, we identified the ten richest (black triangles) and ten poorest (black circles) neighbourhoods. A stark social divide emerges – an affluent central and western Paris versus working-class eastern periphery – that mirrors the geography of tuberculosis mortality.

Figure 4 traces the evolution of these gaps between 1893 and 1950. At the end of the 19th century, the poorest neighbourhoods had tuberculosis mortality rates over 600 per 100,000, 3.5 times higher than those in the richest districts. The gap widened until World War I, when mortality fell faster in wealthier areas. By 1910, poor districts had rates 4.5 times higher. It was only in the interwar period that conditions improved significantly in disadvantaged neighbourhoods. By the late 1930s, the gap had halved, and after World War II, even the poorest neighbourhoods fell below the symbolic threshold of 100 deaths per 100,000, reached by the Champs-Élysées district 50 years earlier.

A public health transformation, and lessons for today

The progressive eradication of infectious diseases drove the spectacular gains in life expectancy observed from the Belle Époque through to World War II. The pace was unprecedented, with nearly six months gained per year. The fight against tuberculosis was at the heart of this journey toward modernity. Its decline also helped reduce deep social inequalities: in the worst-affected periods, tuberculosis mortality in the poorest districts was three to four times higher than in the wealthiest ones.

The determinants of this sharp decline in mortality remain the subject of debate. However, they can be broadly grouped into three main categories. The first relates to investments in public health infrastructure. The gradual connection of homes to modern sanitation systems likely contributed to the reduction of waterborne infectious diseases, as already emphasized by Kesztenbaum and Rosenthal (2017). Meanwhile, the establishment of the Casier Sanitaire (Health Registry) at the turn of the 20th century may have helped reduce airborne disease mortality – particularly from tuberculosis – by identifying high-risk buildings.

The second category involves medical innovations. The introduction of the anti-diphtheria serum and the BCG vaccine against tuberculosis, among other developments, significantly reshaped the public health landscape. However, antibiotics, discovered later, played only a marginal role in reducing mortality before 1950.

The third category reflects broader economic and social transformations. The first half of the 20th century saw strong economic growth, improved living conditions, and a marked decline in income inequality. In addition, the expansion of transportation networks facilitated food supply from rural areas, contributing to better nutrition. 

Life expectancy in Paris has continued to rise in recent times, albeit more slowly: another 20 years were gained between 1950 and 2019, making it the longevity capital it is today. The social and spatial dynamics that have led to this remarkable result are the object of our current research.

References

Bonnet, F., Torres, C., Kesztenbaum, L. and Meslé, F. (2025) Life and Death in a Changing City: Mortality Patterns and Inequalities in Paris, 1890–1949. Population and Development Review. https://doi.org/10.1111/padr.70031 (Data can be accessed here: https://osf.io/wcyft/)

Kesztenbaum, L., & Rosenthal, J. L. (2017) Sewers’ diffusion and the decline of mortality: The case of Paris, 1880–1914. Journal of Urban Economics, 98, 174-186. https://doi.org/10.1016/j.jue.2016.03.001

Olshansky, S.J., Willcox, B.J., Demetrius, L. et al. (2024) Implausibility of radical life extension in humans in the twenty-first century. Nat Aging 4, 1635–1642. https://doi.org/10.1038/s43587-024-00702-3

Woods, R. (2003) Urban-Rural Mortality Differentials: An Unresolved Debate. Population and Development Review, 29: 29-46. https://doi.org/10.1111/j.1728-4457.2003.00029.x