“Women who smoke like men, die like men,” says Professor Prabhat Jha, head of the Centre for Global Health Research at Canada’s St. Michael’s Hospital, in a recent study giving insights into smokers’ lives.

Smokers who quit when they are young adults can live almost as long as people who never smoked, the new research, authored by Jha found.

While smoking cuts at least 10 years off a person’s lifespan, a comprehensive analysis of health and death records in the United States found that people who quit smoking before they turn 40 regain almost all of those lost years, the study said.

For women, the risks of dying from smoking-related causes are 50 per cent greater than found in the studies conducted in the 1980s. “Women and men who smoke both lost a decade of life,” the study said, adding that male or female smokers aged between 25-79 years had a mortality rate three times higher than people who had never smoked. Those who were never smokers were about twice more likely to live to age 80 than were smokers, the study said.

Jha advises governments around the world on disease control strategies and is also the principal investigator of the Million Death Study in India - one of the largest studies of premature deaths in the world.

The latest study used data from the United States’ National Health Interview Survey, where a representative cross-section of the population is surveyed every year about a broad range of health topics.

His findings were published today in the New England Journal of Medicine .

Jha’s team found that people who quit smoking between ages 35 and 44 gained about nine years and those who quit between ages 45-54 and 55-64 gained six and four years of life, respectively.

This study adds to recent evidence from Britain, Japan and the United States that smoking risks involve about a decade of life lost worldwide.

Low-income smokers

Though about 40 million Americans smoke, most of the world’s estimated 1.3 billion smokers live in low- and middle-income countries, including about 300 million in China and 110 million in India.

Worldwide about 30 million young adults begin smoking each year (about half of all young men and 10 per cent of young women) and most do not stop.

In many high-income countries more than half of people who ever smoked have quit, cessation remains uncommon in most low- and middle-income people. On current trends, smoking will kill about 1 billion people in the 21st century as opposed to ‘only’ 100 million in the 20th century.

Tobacco tax

Professor Jha noted that smoking rates in the United States, China and India would decline much faster if their governments levied high taxes on tobacco, as seen in Canada and France. For example, the Government of Philippines raised taxes recently on cigarettes. Taxation is the single most effective step to get adults to quit and to prevent children from starting, he said.

The study is unique as it examines the risks of smoking and the benefits of stopping among a representative sample of Americans. Earlier studies had examined specific groups such as nurses or volunteers who are healthier than average Americans overall. Importantly, the study is among the first to document the generation of women who started smoking when they were young and kept smoking through their adult lives.

The research was funded by the National Institutes of Health, the Canadian Institutes of Health Research and the Disease Control Priorities-3 project of the Bill and Melinda Gates Foundation.

jyothi.datta@thehindu.co.in