Smoking will kill 1 mn pa by 2025: Study

NEW DELHI: The number of deaths from tobacco among Indian men will reach 1 million per year by about 2025, with an average of about 20 years of life lost for each such death, warns a study.Smoking probably caused about 700, 000 deaths in India during the year 2000, including about 550,000 among middle-aged men and about 110,000 among older men with much smaller numbers among women, due to the low prevalence of their smoking. The discovery not only highlights the known dangers of smoking, but shows that tobacco use could be helping to sustain the TB epidemics that are plaguing many parts of the world.The researchers, led by Vendhan Gajalakshmi of the Epidemiological Research Center in Chennai and Dr Richard Peto, at the University of Oxford, stated that smoking caused half of the deaths from tuberculosis in Indian men.The study compared the smoking habits of 43,000 Indian men who had died of various diseases with those of 35,000 men who were still alive from the same area. Among Indian male smokers and non-smokers together, smoking causes half of all deaths from tuberculosis and a quarter of all deaths from any disease in middle age. The risk of TB among smokers was four times that of non-smokers, says Dr Gajalakshmi adding "Almost 200,000 people a year in India die from TB because they smoked."About a quarter of all persistent smokers of cigarettes or of bidis are killed by tobacco before age 70 years, losing about 20 years of life expectancy. A third of the deaths caused by smoking are from vascular disease and half are from tuberculosis or other respiratory diseases. Mortality from tuberculosis is four times as great among smokers as among non-smokers, she notes."Most of the billion people who have TB will just carry it and not die from it - their bodies are keeping that infection under control," says Dr Peto. "But smoking makes the breakdown of that control more likely."The exact mechanism by which smoking increases TB risk is uncertain. But Dr Gajalakshmi says, "Smoking damages the lung''s defence mechanism against chronic TB infection and the infection becomes uncontrollable."Many of the previous studies of smoking were done in developed countries like UK where tuberculosis had already become uncommon as a cause of death, or in developing countries such as China, where the main increase in smoking was too recent for the full hazards yet to have materialised. "Hence, the potential importance of the association between persistent smoking and tuberculosis has been greatly underestimated. For example, the disease was not even indexed in two major reports by the US Surgeon General on smoking and health and two major reports from WHO on smoking and health mentioned the association between smoking and tuberculosis chiefly to dismiss it," says the study. Yet in India, as in many other countries, tuberculosis still remains a major cause of premature death both in early adult life and in middle age, particularly among men who smoke. Of those who died from tuberculosis at ages 25-69 years, 79 per cent in the urban and 73 per cent in the rural study areas had been smokers, as against only about 39 per cent and 44 per cent of the general male population in those areas According to the study the annual number of deaths from smoking must be expected to double between 2000 and 2025, partly because the population of India in early middle age will increase by half (and the populations in later middle age and in old age will both double during the period 2000-25), partly because factors such as obesity and diabetes may become more widely prevalent and partly because bidi consumption per adult appears to have increased somewhat since the 1970s.