Bengaluru Apr 2, 2019, (Research Matters):
Researchers study the trends in smoking in China, Japan, South Korea, Singapore, Taiwan and India.
An estimated 7 million people in the world lose their lives every year due to smoking tobacco, and these numbers are only rising. By 2030, scientists believe that this number could hit 8.3 million and if the trend continues unabated, by the end of the century, the world will lose a billion lives. Most of these deaths would be in low- and middle-income countries that are witnessing rapid socioeconomic changes. In Asia, the tobacco epidemic is surging, and half of the world’s male smokers live in China, India and Indonesia. Asia is also the world’s largest producer and consumer of tobacco. However, how severe is the tobacco epidemic in Asia?
In a new study, an international collaboration of researchers, led by those from Vanderbilt University, USA, have studied the trends in tobacco use in China, Japan, South Korea, Singapore, Taiwan and India. The study, which included a million participants, is a meta-analysis of 20 cohort studies in these countries that collected data on tobacco habits from representative individuals above 35 years of age. The results, published in JAMA Network Open, reveal region–specific tobacco smoking patterns and the resulting mortality.
The researchers analysed data from each of the 20 cohort studies, which included sociodemographic, lifestyle-related and medical information of the participants. The cohort study from India contained details of 150,000 Mumbai residents collected between 1991-1997. The data on smoking habits included whether the participants were current smokers or if they had quit, the age when they started smoking and the number of cigarettes smoked per day. This data was later analysed by the birth year of the participants, their sex and their country/region.
The study found that on average, 65.4% of men and 7.8% of women smoked tobacco in Asia. The average age at which they started smoking was 22.8 years, with 22.1 years for men and 28.2 years for women. The number of cigarettes smoked per day was 16.5, with 17.2 cigarettes for men and 11.2 cigarettes for women. In India, the average age at which the participants began smoking was 22.6 with each smoking an average of 6.8 cigarettes per day.
In all countries, except China, men born in the 1920s showed the highest rates of smoking. In most of them, participants took up smoking earlier than those born before them. Except for urban Chinese women, the number of cigarettes smoked per day continued to increase in those born in recent years, with Japanese men topping the list. On a positive note, younger men also quit smoking at an earlier age than their older counterparts.
Although the prevalence of smoking in women remained very low in these countries compared to other Western countries, there was an increasing trend observed in rural China, Japan, and India. However, there was a higher rate of lung cancer among Asian women than Western women.
The study also found that smoking-associated mortality rates, including that due to lung cancer, increased in all the countries. Tobacco smoking was associated with 12.5% of total deaths and 56.6% of lung cancer deaths in men born before 1920. For those men born during the 1930s or later, these numbers increased to 29.3% total mortality and 68.4% lung cancer deaths. The researchers predict a similar trend among women smokers, although there is limited data available on women smokers.
“If the tobacco epidemic across Asian populations persists or grows steadily, most Asian countries will face the double burden of lung cancer attributable to both tobacco smoking and other background risk factors”, warn the researchers, based on the observed trends.
The researchers suggest that all Asian countries should implement comprehensive tobacco control policies, such as raising tobacco taxes and prices, implementing smoke-free laws and bans on advertising and promotion, providing assistance to those who quit smoking, and using warning labels on tobacco packages, to end the tobacco epidemic.
“For current smokers, quitting as soon as possible is the best strategy to reduce the risk associated with smoking,” they conclude.