India is in the midst of a smoking epidemic which will kill about a million people annually, accounting for nearly one in every 10 deaths from 2010, researchers said Wednesday.
Some 70 percent of those people will die before they reach the age of 70, according to the study published in the New England Journal of Medicine.
"I am alarmed by the results of this study," India's Health Minister Abumani Ramadoss said in a statement.
"The government of India is trying to take all steps to control tobacco use -- in particular by informing the many poor and illiterate of smoke risks."
The first nationally representative study of smoking habits and associated mortality rates found that some 120 million Indians smoke, although they generally pick up the habit later in life.
Some 37 percent of men and about five percent of women aged 30 to 69 smoke either cigarettes or leaf-wrapped bidis, which are unfiltered and contain about a quarter as much tobacco as a cigarette.
The study projected that smoking will cause one in five deaths of Indian males and one in 20 deaths of Indian females aged 30 to 69 in the coming decade.
Men who smoked cigarettes lost an average of 10 years of life, while smoking bidis cut an average of six years off the life expectancy of men and eight years off of the lives of women.
Even light smokers saw their mortality risk jump: smoking between one and seven cigarettes a day nearly doubled the mortality risk while smoking the equivalent number of bidis raised mortality risks by a third.
Quitting smoking has been shown to greatly reduce the mortality risk. But it is an uncommon phenomenon in India, where only about two percent of adults have quit, and they often did so only after they fell ill, the study found.