All parents fondly wish that their children grow to enjoy a full and fulfilling life. Those children too desire to age well so that their lives are not marred by disease and disability. They hope to remain fit and functioning rather than frail and feeble till the end of their life. It will be a poor trade off if their life expectancy increases but those added years are full of suffering due to poor health.
The 20th century saw a marked rise in human life expectancy globally, despite world wars and a host of infectious diseases. This resulted from a combination of improved living conditions and advances in preventive, diagnostic and curative medical services. Improvements in water, sanitation, nutrition, education, income, occupational safety and women’s status in society accompanied economic development and education.
These also stimulated a surge of science and technology. Simultaneously, large populations in Asia, Africa and the Americas wrested freedom from colonial rule and charted their developmental journeys. More diseases were prevented and more lives were saved than ever before, to yield a bounty of long life expectancy. However, even a ‘cured’ disease often left behind disabilities that detracted from fulsome functionality and impaired the quality of life, increased dependency on others and carried high financial costs of chronic healthcare.
In the second half of the 20th century, maladies of maladapted modernity overtook infectious diseases, nutritional disorders and imperilled maternal and child health as the principal contributors to disease, disability and death. These ‘non-communicable’ diseases included cardiovascular diseases like heart attacks and brain strokes, diabetes, chronic respiratory diseases, cancers and disorders of kidneys, liver, joints, ears and eyes. Towards the end of the 20th century, overweight and obesity started rising alarmingly in many parts of the world.
While many of these disorders were called ‘lifestyle diseases’, they were propelled by commercial drivers. A wide variety of tobacco products, ultra-processed foods, sugar-sweetened beverages, alcoholic intoxicants and narcotic drugs assaulted the body. These advertised addictions resulted in marketed maladies on a global scale, as production and sales became transnational activities.
The advent of automobiles, television, and later the internet saw a sharp rise in sedentariness and a decline in physical activity. As people became digitally hyper-connected, they became emotionally disconnected. This has been manifest, especially among young people. Road traffic accidents are rising in most countries, as are deaths from suicidal and homicidal violence. Air pollution is injuring human bodies everywhere, while climate change is bringing a host of new health challenges.
Skewed civilisational progress in the 21st century has seen a rise in life expectancy or ‘lifespan’, with a lag in healthy life expectancy or ‘health span’. A recent study of these global trends was published in the Journal of the American Medical Association (2024). Armin Garmany and Andre Terzic accessed data on 195 countries from the World Health Organization’s Global Health Observatory. They reported on changes in life expectancy and healthy life expectancy between 2000 and 2019, in different countries and in both sexes.
Globally, the mean gap between life expectancy and healthy life expectancy, during this period, was 9.6 years. The gap was wider by 2.4 years in women than in men. The largest gaps between life expectancy and healthy life expectancy were seen in the United States (12.4 years) and the United Kingdom (11.3 years). While accelerated economic development gave these countries a high life expectancy, they failed to ensure good health of their populations during those added years. Countries with low life expectancy (like Lesotho) showed a lower gap between it and healthy life expectancy, indicating that large gains need to be made in both metrics as low-income countries ascend the development ladder.
During 2000-2019, India’s life expectancy grew at the rate of 0.43 per year. Healthy life expectancy grew at the rate of 0.37 per year. This widened the gap between life expectancy and healthy life expectancy. Healthy life expectancy in India was a decade behind overall life expectancy in 2022. The gap was 10.49 years in both sexes combined, while it was 9.22 years in men and 11.77 years in women.
As India aims to achieve a high level of development by 2027, we need to prioritise promotion and protection of health across the life course for all our citizens. Otherwise, our aspirations for accelerated development will not fructify and our ambitions to become an economic superpower will be thwarted.
The Chief Economic Advisor to the Indian government, V Anantha Nageswaran, recently pointed out that India will be unable to reap economic benefits from the demographic dividend of a young population if the physical and mental health of young people is not protected. The pre-budget Economic Survey of 2024 noted that 56.4 per cent of India’s present health burden is due to unhealthy diets. We need a policy response.
India is now the world’s most populous country. We cannot afford to have a large segment of the population living many years of their life with poor health and low functionality. It is essential that we protect health across the whole life course so that we avert or attenuate the burdens of disease and disability at each stage.
While much of the gap between lifespan and healthspan arises in the last two decades of life, the erosion of health often begins in earlier years. The pathophysiology of adult cardiovascular disease and diabetes is linked to nutritional influences in the early years of life. Our attempts to reduce the burden of disease in later life must commence from the preconception period and extend throughout life, through policies and programmes that promote and protect health coupled with efficient, accessible and affordable health services that restore deranged health. Only when we undertake these measures can we achieve a narrow lifespan-healthspan gap.
(Views are personal)
K Srinath Reddy
Author of Pulse to Planet; Distinguished Professor of public health, PHFI
(ksrinath.reddy@phfi.org)