11% of denizens risk premature death with smoking, alcohol: Study

CHENNAI: A landmark study involving more than 5 lakh adults in Chennai has found that low educational attainment, smoking and alcohol consumption are strongly associated with premature mortality, with researchers reporting that social inequalities remain one of the most powerful determinants of health outcomes in urban India.

Published in the international journal Nature Health, the study was conducted by researchers from the Chennai-based Epidemiological Research Centre and the University of Oxford’s Nuffield Department of Population Health.

The paper titled, ‘Combined Impact of Smoking, Alcohol and Social Inequalities on Premature Mortality in Urban India’, tracked 5,00,810 adults aged 35 years and above recruited between 1998 and 2001 and followed them until 2020. Researchers described it as the largest prospective study in India examining the combined impact of education, smoking and alcohol consumption on premature mortality.

For the main analysis, researchers excluded 33,323 participants aged 70 years and above, and 8,878 individuals with chronic illnesses at enrolment, leaving 4,58,609 adults for detailed assessment. Over an average follow-up period of 16.4 years, the study recorded 52,127 deaths among participants aged between 35 and 69 years, including 31,337 men and 20,790 women.

The most striking finding was the scale of mortality differences linked to education. Even among people who neither smoked nor consumed alcohol, those with no formal schooling faced nearly three times the risk of dying before the age of 70 compared with those who had more than 11 years of education.

Among non-smoking and non-drinking participants, men with no schooling had a mortality rate 2.76 times higher than those with tertiary education, while women with no schooling had a mortality rate 2.93 times higher than their better-educated counterparts. The study found that educational inequalities extended across virtually every major disease category.

The widest gap was observed in tuberculosis mortality, where adults with no schooling were 4.17 times more likely to die than those with secondary education. Mortality from other respiratory diseases was 3.35 times higher among the least educated participants.

Substantial excess mortality was also recorded for stroke, heart disease, kidney disease, cancer, other medical conditions and non-medical causes of death.

The findings indicated that factors beyond individual lifestyle choices contributed significantly to health outcomes. Educational attainment emerged as a stronger predictor of mortality than household asset-based socio-economic status, suggesting that broader social and structural disadvantages continue to influence survival.

The study also documented a strong relationship between education levels and the prevalence of tobacco and alcohol use among men.

Among men with no schooling, 53% were current smokers and 45% were current alcohol consumers. In contrast, only 16% of men with more than 11 years of education smoked and 10% consumed alcohol.

Overall, 35% of men in the study were current smokers and 26% were current drinkers. Researchers found that 65% of men with no schooling either smoked or drank alcohol, compared with just 21% among men with tertiary education.

The average smoker consumed around 11 cigarettes or bidis a day and began smoking at about 22 years of age. The study found that bidi smokers experienced higher mortality rates than cigarette smokers, although part of the difference was linked to lower educational attainment and higher alcohol consumption among bidi users.

After adjusting for age, education and socio-economic status, smoking was associated with a 26% increase in mortality risk, while alcohol consumption was associated with a 52% increase.

Men who both smoked and consumed alcohol faced the greatest risk. Their mortality rate was nearly double that of men who neither smoked nor drank, with a mortality risk ratio of 1.89. Researchers estimated that smoking and drinking together accounted for about 22% of all male deaths in the study population.

The findings also challenged claims that moderate alcohol consumption offers cardiovascular benefits. Researchers reported higher mortality among drinkers across all major disease categories and found no evidence that moderate drinking provided protection against cardiac deaths.

Women displayed markedly different patterns. Fewer than 0.1% of women reported smoking or consuming alcohol, enabling researchers to assess educational inequalities in mortality largely independent of these behavioural risk factors.

The study highlighted the scale of the mortality divide. Among men who neither smoked nor drank, the estimated probability of dying before the age of 70 ranged from 19% among those with tertiary education to 45% among those with no schooling. Among men who both smoked and drank, the risk rose to around 60% for those without schooling.

According to the authors, smoking and alcohol consumption amplified existing social inequalities rather than fully explaining them. While tobacco and alcohol remain major causes of preventable deaths, the study found that educational disadvantage alone was associated with substantially higher mortality across almost every category of disease.

The researchers said the findings underline the need for public health policies that go beyond tobacco control and alcohol reduction. Expanding educational opportunities, improving access to healthcare, strengthening disease prevention programmes and addressing wider social inequalities will be critical to reducing premature mortality, they said.

The study was led by Vendhan Gajalakshmi of the Epidemiological Research Centre, Chennai, along with Fiona Bragg, Ben Lacey, Richard Peto and Sarah Lewington of the University of Oxford. Drawing on more than two decades of follow-up data from Chennai residents, the researchers concluded that social inequalities, smoking and alcohol consumption continue to exact a substantial toll on adult survival, with education emerging as one of the strongest predictors of longevity in urban India.

RESULTS OF THE STUDY

Nature Health study tracked over 5 lakh Chennai adults from 1998–2020, making it one of India’s largest mortality studies

• Adults with no schooling faced nearly 3 times higher risk of dying before 70 than those with tertiary education

• Smoking increased mortality risk by 26%, alcohol by 52%

• Men who both smoked and drank had 89% higher mortality risk than those who did neither

• 65% of men with no schooling smoked or drank, against 21% among the highly educated

• TB deaths over 4 times higher and respiratory disease deaths over 3 times higher among the least educated

• Less than 0.1% of women reported smoking or drinking

BLURB

Even among people who neither smoked nor consumed alcohol, those with no formal schooling faced nearly three times the risk of dying before the age of 70 compared with those who had more than 11 years of education

The average smoker consumed around 11 cigarettes or bidis a day and began smoking at about 22 years of age. The study found that bidi smokers experienced higher mortality rates than cigarette smokers

Researchers reported higher mortality among drinkers across all major disease categories and found no evidence that moderate drinking provided protection against cardiac deaths