How much has life expectancy plateaued, and where is it worst?
The plateau is real and measurable, but its size and timing vary sharply by country. The clearest evidence comes from a 2025 study that tracked life expectancy at age 65 across the Americas from 2000 to 2019 [2]. During the first decade (2000–2010), the US, Canada, and Costa Rica all saw substantial gains of 1.3 to 2 years, driven largely by falling deaths from cardiovascular disease. But from 2010 to 2019, those gains collapsed to just 0.5 to 1 year—a clear slowdown. The main reason: the contribution of better heart-disease treatment to longer life more than halved after 2010 [2]. That means the easy wins from tackling heart disease are fading, and no new driver of longevity has stepped in to replace them.
The United States is in a league of its own when it comes to stagnation. A 2023 analysis of US life expectancy from 1933 to 2021 found that growth has been progressively deteriorating since the 1980s: from 0.34 years per year in 1974–1982 down to just 0.06 years per year in 2010–2019, and then a catastrophic drop of -0.97 years per year in 2020–2021 [1]. Over that entire period, 56 other countries on six continents surpassed the US in life expectancy. The worst stagnation within the US is concentrated in the Midwest and South Central states, and among Black Americans, whose life expectancy actually declined after 2010 in all metropolitan categories in the Midwest [3].
What is causing life expectancy to stall?
Three main forces are driving the plateau, and they reinforce each other. First, the long-running decline in deaths from heart disease—the single biggest contributor to rising life expectancy for decades—has slowed dramatically. In the US, Canada, and Mexico, the contribution of cardiovascular disease to gains in life expectancy at age 65 more than halved after 2010 [2]. This is not because heart disease has been solved; it is because the easiest progress has already been made, and further gains require tackling harder problems like obesity, poor diet, and physical inactivity.
Second, substance misuse is actively reversing progress, especially in the US. A 2025 review of substance use disorders notes that the US now ranks 27th among developed countries in life expectancy, and that the rate has plateaued and is declining for certain subpopulations—a trend driven largely by drug and alcohol deaths [4]. This is not a minor factor: the same review calls the costs of substance misuse 'staggering,' including lost productivity, health care costs, and rising mortality among working-age adults.
Third, the COVID-19 pandemic delivered a sharp, one-time blow. A 2022 analysis of global mortality data found that the pandemic halted more than a decade of life expectancy increases, with decreases in 2020 in 31 out of 37 high-income countries [5]. For the US, the pandemic compounded an already weak trajectory, turning stagnation into outright decline.
Can changing what we eat make a meaningful difference?
Yes—dietary changes are one of the most powerful levers available, and the modeling suggests the potential gains are large. A 2024 comparative modeling study estimated that if 40-year-old Americans switched from their typical diet to a longevity-optimized diet (more whole grains, legumes, nuts; less red and processed meat and sugar-sweetened beverages), they could gain up to 9.7 additional years of life expectancy [6]. For US males, that was the largest projected gain of any country studied. Even a more feasible dietary change or an optimized vegan diet still projected gains of 5 to 9 years, depending on the country and sex [6].
However, these are model-based projections, not observed outcomes. The study used dose-response data from meta-analyses and adjusted for height, weight, and physical activity, but it assumes sustained behavior change over decades—something that is notoriously difficult to achieve at a population level. Still, the size of the effect (6–10 years for the US) dwarfs the recent stagnation (0.5–1 year per decade), suggesting that diet is a credible path to restarting progress, if the political and social will to change food environments exists.
About These Sources
This answer is built on 6 peer-reviewed studies — published from 2022 to 2025, 4 from 2024 or later, 5 in Q1 journals, collectively cited 89 times — selected as the most relevant from 6 studies that passed quality screening, drawn from 54 papers retrieved from a database of over 500 million.
Sources used in this answer
Falling Behind: The Growing Gap in Life Expectancy Between the United States and Other Countries, 1933–2021
US life expectancy growth has progressively deteriorated since the 1980s, falling from 0.34 years/year (1974–1982) to 0.06 years/year (2010–2019) and then -0.97 years/year (2020–2021); 56 countries have surpassed the US since 1933.
Catching up with stagnation: cause-specific dynamics of change in life expectancy at age 65 in the United States, Canada, and Latin America, 2000–2019
In a study of the Americas (2000–2019), gains in life expectancy at age 65 slowed from 1.3–2 years (2000–2010) to just 0.5–1 year (2010–2019), driven by a more-than-halving of the contribution from cardiovascular disease reductions.
Pre‐COVID‐19 Geographic Inequalities in Non‐Hispanic Black US Life Expectancy, 1990–2019
Among non-Hispanic Black Americans, life expectancy gains stalled after 2010 and actually declined in all metropolitan categories in the Midwest, with the largest improvements concentrated in large central and fringe metro areas.
Substance Use Disorders
The US ranks 27th among developed countries in life expectancy; the rate has plateaued and is declining for certain subpopulations, a trend driven largely by substance misuse.
COVID-19 Cuts Life Expectancy in Dozens of Countries
The COVID-19 pandemic halted more than a decade of life expectancy increases, causing decreases in 2020 in 31 of 37 high-income countries.
Life expectancy gains from dietary modifications: a comparative modeling study in 7 countries
Modeling estimates that sustained dietary changes (more whole grains, legumes, nuts; less red/processed meat and sugar) could yield life expectancy gains of 6.2–9.7 years for 40-year-olds, with the largest gains projected for US males.