Humans

Education and lifestyle drive premature mortality in urban India

Among non-smoking non-drinkers, uneducated adults had higher mortality than those with over 11 years of schooling, with rate ratios of 2.76 in men and 2.93 in women.

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Figure 1Gajalakshmi et al.

Nature Health

Researchers evaluated 500,810 adults aged 35 years and older in Chennai, South India, who were recruited between 1998 and 2001 and followed through 2020. Among participants initially free of chronic disease, multivariable-adjusted Cox regression related baseline characteristics to cause-specific mortality censored at age 70.

Even among non-smoking non-drinkers, having no schooling versus more than 11 years of education was associated with a mortality rate ratio of 2.76 in men and 2.93 in women, with substantial excess deaths across each major disease category. Higher smoking and drinking rates among less educated men further compounded these disparities. Adjusted for education, male smoking had a rate ratio of 1.26 and drinking had a rate ratio of 1.52. Men with both habits had a rate ratio of 1.89 compared to those with neither. Less than 0.1% of women smoked or drank.

Why it matters

The findings show that social determinants and behavioral exposures interact to substantially drive premature mortality prior to age 70. Quantifying these combined effects helps longevity researchers understand the social gradients that shape human lifespan and healthspan across diverse populations.

Caveats

The investigation was observational and restricted to a single urban center, with causes of death assessed via verbal autopsy rather than clinical records. Furthermore, the direct mortality effects of smoking and alcohol could not be assessed in women because fewer than 0.1% used either substance.

The paper

Combined impact of smoking, alcohol and social inequalities on premature mortality in urban India

National Institute of Epidemiology · University of Oxford

Nature Health · 19 Jun 2026

doi.org/10.1038/s44360-026-00148-4PubMed 42827579

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