Living Longer, Sicker: Why Healthspan Must Catch Up to Lifespan

A teenager managing Type 2 diabetes. A 35-year-old navigating a colorectal cancer diagnosis. A parent in their 40s juggling work, caregiving, and the early signs of heart disease. These stories are no longer rare.

Life expectancy in the United States has climbed more than 40 years since 1900, yet a growing body of research suggests that we are living sicker lives, and the burden of poor health is also showing up earlier.

Public health researchers distinguish between lifespan (total number of years a person lives) and healthspan (how many of those years are spent in good health). The widening gap between the two reflects a central paradox: we have extended life without consistently improving its quality.

This pattern is visible across conditions once thought to affect primarily older adults. Type 2 diabetes, for example, is rising rapidly among adolescents. Compared with older adults, young people diagnosed with Type 2 diabetes are more likely to develop related complications earlier, including kidney disease, cardiovascular disease, and vision loss.

Among U.S. adults, cancer diagnoses, such as breast, pancreatic, and gastric, are emerging earlier and more frequently in people under 50. Pancreatic cancer diagnoses among younger adults are increasing faster than among older populations, and colorectal cancer incidence among adults under 50 continues to rise by nearly 3% each year. Many individuals are also managing multiple chronic conditions earlier in life, compounding their impact over time.

This is not just about aging differently. It’s about entire generations entering adulthood already on a chronic disease trajectory.

The consequences of this shift in our health shape the arc of everyday life. A diagnosis at age 30 instead of 60 can mean decades more of medical care, financial strain, and physical and mental burden. Investment firm Vanguard reported hardship withdrawals from 401(k) accounts reached a record high of 6% in 2025, driven largely by financial strain, particularly the need to avoid eviction or housing foreclosure and to pay for medical bills. Life stages typically associated with stability in our 40s and 50s are increasingly interrupted by illness, limiting mobility and eroding people’s ability to participate fully in family, work, and community life.

A global lens shows us that better outcomes are not only possible; they are already being achieved elsewhere.

So why is chronic disease appearing earlier in life? The answer is complex and multi-factorial. Individual behaviors such as diet, physical activity, and sleep matter. But a substantial body of evidence shows that these behaviors are shaped by broader social, environmental, and economic conditions that structure daily life. What often appears as personal choice is, in many cases, constrained or influenced by the environments people live in.

Today’s food environment is dominated by inexpensive, ultra-processed products that account for nearly 60% of caloric intake among U.S. adolescents and adults. These products are often engineered for shelf life and palatability, yet are high in added sugars, sodium, and unhealthy fats and low in nutrients. At the same time, growing evidence points to the role of environmental exposures, including pesticides, endocrine-disrupting chemicals, and other byproducts of modern food production and packaging, in shaping metabolic health and chronic disease risk. Emerging research on microplastics and the growing field of epigenetics and environmental health further suggests that these exposures may influence health across the life course and over generations.

Meanwhile, sedentary lifestyles have become the default when we know that movement is medicine. The average adult spends six to eight hours per day sitting, and fewer than one in four adolescents meet physical activity recommendations. These are predictable outcomes of environments designed for the conveniences of modern life.

The path forward is not a single breakthrough, but a collective shift in how we design the environments people move through every day.

While these trends are not unique to the U.S., their consequences are particularly stark here. Compared with other high-income countries such as Canada, the United Kingdom, and nations across Western Europe, Americans develop chronic disease earlier and live shorter lives, despite spending significantly more on health care. A global lens shows us that better outcomes are not only possible; they are already being achieved elsewhere.

Closing the gap between lifespan and healthspan will require looking beyond the health care system alone. While health care plays a critical role in treating disease, it accounts for only a fraction of what shapes population health outcomes. Just as individual responsibility is not the sole driver of health, the health care system cannot bear full responsibility for creating the conditions that sustain it. Governments, schools, the food industry, urban planners, and media all shape the environments that influence health, often in ways that go unnoticed but accumulate over time.

The path forward is not a single breakthrough, but a collective shift in how we design the environments people move through every day. Policies that support healthier and affordable food access and systems, clean air and water, stable housing, neighborhoods designed for movement, and access to affordable medications are structural changes with benefits that can scale and accrue across a lifetime.

The question is no longer whether we can live longer (we already are). The question is how can we partner with other sectors and bridge divides to redesign the conditions that determine how our lives are lived.

The views expressed here are the authors’ own and do not necessarily represent the views of Public Health Post or Boston University School of Public Health.