Global life expectancy has reached 73.8 years, but progress in longevity is increasingly decoupled from health quality. A new study published in The Lancet Public Health reveals that in 2023, the average person spent 14.5 per cent of their life in poor health, a trend driven by rising non-fatal disabilities.
The Widening Gap Between Lifespan and Healthspan
While humanity has succeeded in drastically reducing mortality from infectious diseases and maternal health crises, these gains have not translated into a proportional increase in healthy years. According to research from the Institute for Health Metrics and Evaluation (IHME), life expectancy gains are now consistently outstripping improvements in healthy life expectancy across 204 countries and territories.
The data indicates that in 2023, residents of the wealthiest nations spent 15.7 per cent of their lives in poor health. This represents a significant shift from 1990, particularly in countries like the Netherlands, which saw its proportion of time spent in poor health rise from 13.2 per cent to 15.7 per cent over the same period.
Drivers of Global Morbidity
The study identifies non-fatal conditions as the primary contributors to this health gap, accounting for 57.4 per cent of the global morbidity burden. These include musculoskeletal disorders such as low back pain, mental health conditions, and sensory impairments like age-related hearing loss. In lower-income regions, these challenges are compounded by nutritional deficiencies, tuberculosis, and respiratory infections.
Researchers also highlighted how specific risk factors correlate with these outcomes. High body mass index, tobacco use, and air pollution remain universal drivers of poor health. In high-income super-regions, alcohol and drug use emerged as leading contributors, whereas unsafe sex remains a primary factor in sub-Saharan Africa.
Lifestyle Interventions and Cognitive Health
While systemic changes are required to address the global morbidity gap, individual lifestyle choices continue to play a documented role in extending “healthspan.” A separate observational study published by BMJ tracked 2,500 individuals over two decades, finding that healthy habits can significantly delay the onset of conditions like Alzheimer’s disease.
The study defined a healthy lifestyle score
based on five factors: plant-based nutrition, cognitive engagement, regular exercise (at least 150 minutes per week), smoking cessation, and moderate alcohol consumption. Participants who maintained four or five of these factors not only lived longer—with men gaining nearly six years of life expectancy compared to those with one or no healthy habits—but also cut the number of years lived with Alzheimer’s disease in half.
The Sustainability of Future Health Systems
The findings from the IHME team suggest that the current model of healthcare, which prioritizes survival, is becoming unsustainable. Christopher Murray, director of the IHME at the University of Washington School of Medicine, argues that the focus must shift toward prevention and long-term chronic care.
As policymakers weigh these results, the unresolved question remains how nations will reallocate resources to support this transition. With economic modeling suggesting that targeting ageing offers larger financial returns than focusing solely on eliminating specific diseases, the pressure to integrate rehabilitation and mental health services into standard geriatric care is likely to intensify.
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