Well-being & Health

"Degrowth makes you sick": what the data actually says

80% of our longevity is determined by lifestyle, not genes. Societies that consume less often live longer, with better mental health and more meaning. Here is the evidence.

Published on 11 min de lecture

“Degrowth makes you sick”: what the data actually says

TL;DR: The objection comes up often: consuming less, slowing down, stepping outside the growth cult — that amounts to condemning ourselves to an impoverished, less healthy life. The data says otherwise. In the regions where people live the longest on earth, inhabitants work less, travel on foot, eat little meat and sleep a great deal. This is not rural nostalgia — it is measured, published and reproducible. This article documents the evidence.

There is an objection you will hear in every discussion about ecological transition or degrowth. It goes like this: “All very well, but you can’t ask people to live like it’s the Middle Ages. Less growth means fewer doctors, fewer medicines, less well-being.”

This objection has a factual problem.

The five regions of the world where people live the longest — what researchers call Blue Zones — are not hyperconnected urban centres running at maximum consumption. They are rural communities in Sardinia, Greek islands, coastal villages in Costa Rica, an Adventist city in California and the island of Okinawa in Japan. Their inhabitants reach the age of 100 ten times more often than Americans on average.

This is not a genetic accident. The Danish twin study established that only 20% of lifespan is determined by genes. The remaining 80% depends on lifestyle. What you eat, how you move, who you spend time with, whether your life has meaning: these factors weigh four times more than your biological inheritance.

The subject of this article is not to persuade you to flee the city and grow beans. It is to put the data on the table: societies that consume less do not fare worse. They often fare better.

The centenarians’ secret: nine measurable habits

Researchers Dan Buettner and Sam Skemp spent two decades identifying the common factors across Blue Zones. They identified nine — the “Power 9” — that cut across very different cultures, religions and latitudes.

None of them involve spending more.

Centenarians in Sardinia and Ikaria move naturally: they garden, walk, make cheese by hand. They do not go to gyms — they have no need of them, because their built environment makes movement inevitable. They eat mainly legumes, vegetables and whole grains, with little meat. They have a strong sense of community belonging. And they have what the Japanese call ikigai: a reason to get up in the morning.

That last point is perhaps the most surprising: knowing one’s sense of purpose is worth up to seven additional years of life expectancy, according to Blue Zones data. Not a medicine. Not a premium insurance plan. A sense of meaning.

The question is not “can we afford to live this way?” but “what do we choose to measure as wealth?”

Nature is not a luxury: it is medicine

In 2004, the Japanese Society of Forest Medicine was established and the Japanese government launched a national research programme to scientifically document the effects of Shinrin-yoku — forest bathing — on human health. This was not a wellness trend: it was a response to accumulated clinical data.

A 2022 review published in Environmental Health and Preventive Medicine documents the measured effects: Shinrin-yoku reduces blood pressure and heart rate, lowers stress hormones (urinary adrenaline, noradrenaline, salivary cortisol), increases NK cell activity — natural killer cells that play a role in cancer prevention — and in standardised psychological tests, reduces scores for anxiety, depression, anger, fatigue and confusion while increasing vitality.

These effects do not require a deep forest or a weekend in the countryside. A meta-analysis of 78 studies (1990–2020) published in 2025 in Behavioral Sciences establishes that 20 to 30 minutes of nature exposure is sufficient to reduce salivary cortisol by 21% and salivary amylase by 28%. Even urban nature — a park, a tree-lined avenue — produces measurable effects in ten minutes.

The same study identifies a threshold: 120 minutes per week spent in natural spaces are associated with a significantly greater probability of reporting good health and overall well-being. Below that threshold, the effect diminishes. Above it, it is sustained. And if the whole population reached this minimum of 30 minutes of weekly contact with green spaces, models suggest up to 7% fewer cases of depression and 9% fewer cases of hypertension.

The prescription is free. It requires accessible green space — that is a question of urban planning, not personal budget.

The plate that adds ten years

Changing diet is the lifestyle modification with the largest documented impact on life expectancy.

A study published in 2022 in PLOS Medicine modelled the impact of a sustained dietary change on life expectancy. Result: switching from a typical Western diet to an optimal diet starting at age 20 would add 10.7 years for a woman and 13.0 years for a man. Even a change started at age 60 still gains 8.0 years for a woman and 8.8 years for a man.

The largest gains come from increased consumption of legumes, whole grains and nuts — and from a reduction in red and processed meat. Foods among the least expensive in the global food basket.

It is no coincidence that the Mediterranean diet — olive oil, vegetables, fish, legumes, dried fruits — is associated in many prospective studies with prevention of cardiovascular, metabolic, neurodegenerative and cancer diseases, as well as depression. UNESCO inscribed it on the Intangible Cultural Heritage of Humanity in 2010: an acknowledgement that this way of eating is inseparable from a way of living together.

The EAT-Lancet Commission, which brought together 37 leading scientists in 2019, asked the question directly: can we feed 10 billion people healthily within planetary boundaries? The answer is yes — provided dietary habits are transformed. Healthy eating and sustainable eating are not in opposition. They converge.

The city that frees up time

Anne Hidalgo made Paris the global laboratory for a concept born at the Université Paris 1 Panthéon-Sorbonne: the 15-minute city. The idea: urban quality of life is inversely proportional to time spent in transit. The more kilometres you travel to access essential functions — work, shopping, healthcare, education, entertainment — the lower your quality of life.

The average American driver loses 54 hours per year in traffic jams, according to the concept’s data. That is not mobility — it is life-time evaporated.

The alternative does not require renouncing modernity. It requires reorganising space so that essential needs are within walking or cycling distance. The health effects are independently documented by the WHO and international research.

The WHO European Regional Office establishes that walking 30 minutes or cycling 20 minutes most days reduces mortality risk by at least 10%. Commuter cyclists show cancer-related mortality 30% lower. Active commuting is associated with a 10% reduction in cardiovascular risk and a 30% reduction in type 2 diabetes risk. And physical inactivity causes one million deaths per year in the European region.

A 2025 study published in PNAS covering 11,587 cities in 121 countries simulated what would happen if all cities in the world reached the level of cycling infrastructure found in Copenhagen. Result: a 6% reduction in private vehicle emissions and $435 billion in annual health benefits. For every new kilometre of cycle path, the study estimates 13,400 additional cycle-kilometres per year.

Active mobility is not a constraint imposed on people who cannot afford a car. It is the infrastructure that produces the most health per euro invested.

When governments change their metrics

In the late 1970s, the fourth King of Bhutan said something that would take several decades to be taken seriously in economic circles: “Gross National Happiness is more important than Gross Domestic Product.”

This was not wishful thinking. Bhutan built a Gross National Happiness Index (GNH) measuring nine domains: psychological well-being, health, time use, education, cultural diversity, good governance, community vitality, ecological diversity, living standards. Thirty-three indicators, drawn from surveys of more than 11,000 Bhutanese. The GNH index rose from 0.743 in 2010 to 0.781 in 2022 — a measurable progression over a decade.

This model is no longer isolated. The Wellbeing Economy Governments (WEGo) partnership, launched in 2018, brings together national and regional governments that share their practices to build “wellbeing economies”: Scotland, Iceland, New Zealand, Wales, Finland and Canada are among them.

The Finnish experience deserves particular attention. Finland conducted Europe’s first large-scale universal basic income experiment between 2017 and 2018: 2,000 recipients received an unconditional monthly allowance for two years, compared with a control group. The official results from the Finnish Ministry of Social Affairs show that recipients were more satisfied with their lives and experienced less psychological strain than the control group. Their perception of their economic security was higher. In employment terms, the effect was moderate: +6 working days on average. What the experiment measured above all was mental health — and it improved.

The OECD measures well-being systematically since 2011 with its How’s Life? report, whose sixth edition (2024) covers more than 80 indicators across member countries. One result deserves noting: between 4 and 14% of inhabitants in OECD countries feel lonely, depending on the country. Loneliness is measured, compared, taken seriously — because it is associated with health effects as serious as those documented for smoking. GDP growth does not automatically reduce it.

What “less” really means

It is worth being honest about what these data do not say.

They do not say that poverty is good for health. Blue Zones are not communities in destitution — they have access to healthcare, sufficient food, a solid social fabric. The Mediterranean diet requires olive oil and fresh fish, not just willpower. The 120 weekly minutes in nature presuppose that nature is accessible — which is a political question, not an individual one.

These data say something more precise: the trajectory “ever more consumption = ever more health and happiness” is not supported by the facts. Beyond a threshold of income that covers basic needs, gains in well-being come less from additional spending than from the quality of social bonds, time outdoors, minimally processed food and a sense of meaning.

This is not “going back to the Middle Ages”. It is recognising that our wealthy societies have over-invested in certain sectors (cars, ultra-processed food, fragmented urban planning) and under-invested in others (green spaces, active mobility, free time, community ties).

What you can do today

The Blue Zones data points to nine measurable habits. There is no need to adopt them all at once. The effects are gradual and documented.

Three entry points with the highest health return on investment, according to the data compiled here:

  1. 120 minutes per week in a natural space. Not a forest — a local park is sufficient. The effect on cortisol and mental health is robust across 78 studies.

  2. Replace one daily car trip with walking or cycling. The WHO and PNAS data are unambiguous: 20 to 30 minutes of active mobility per day significantly shifts cardiovascular and metabolic risks.

  3. Increase legumes, whole grains and nuts in your diet. These three groups account for the largest gains in life expectancy documented by PLOS Medicine 2022 — and are among the least costly foods available.

These individual choices make more sense within a collective framework: a city that invests in cycle paths, local parks, accessible quality food. The personal level and the political level reinforce each other. The demonstration that it is possible has already been made — in Copenhagen, in Ikaria, in Paris, in Bhutan.

The question is no longer whether these societies exist. It is whether we choose to be inspired by them.

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