DALLAS, April 8, 2020 -- The younger you start smoking, the more likely you are to smoke daily as an adult, even into your 40s, and the harder it will be to quit, according to new data from a long-standing, international study published today in the Journal of the American Heart Association, an open access journal of the American Heart Association.
The new research has the longest follow-up of any study focused on smoking at an early age, using information obtained directly from children and adolescents in the 1970s to 1980s and re-contacting many of them as recently as 2018.
"Based on our data coupled with a variety of other evidence, we found childhood smoking leads to adult smoking," said David Jacobs, Jr., Ph.D., lead study author and Mayo Professor of Public Health in the Division of Epidemiology and Community Health at the University of Minnesota in Minneapolis. "Cigarette smoking, even experimentally, among children of any age should be strongly discouraged."
Researchers analyzed smoking information on more than 6,600 people (57% female) between the ages of 6-19 and during their 20s and 40s, from Finland, Australia and the United States. Participants were followed from childhood into middle age as part of the International Childhood Cardiovascular Cohort Consortium.
The study analysis found:
Adolescents who smoked the most and children who started smoking at younger ages were more likely to be daily smokers in their 20s and were less likely to quit smoking by their 40s.
Even children who only tried smoking at a very minimal level - a few cigarettes - were more likely to end up as a daily adult smoker.
The percentage of participants who smoked daily during their 20s was 8% for those who first tried smoking at age 18-19; 33% for those who first tried smoking at age 15-17; 48% for those who first tried smoking at age 13-14; and 50% for those who first tried smoking during ages 6-12.
Only 2.6% of participants who took up smoking for the first time after their 20s smoked in their 40s.
The frequency of smoking in childhood and adolescence was similar in Finland, Australia and the United States.
Although the current study was conducted in three developed nations, the researchers believe that the results likely apply more broadly.
"Even in low income and developing countries, the societal reinforcement of smoking, the basic addictive qualities of nicotine, and the maturation of children and children's judgment through adolescence are universal," said Jacobs. "As children mature through adolescence, they may have developed a better ability to resist impulses and to reject social pressures.
"Cigarette smoking is an avoidable health risk, and its seeds are in childhood. These results strongly support Tobacco 21, a national movement to restrict all sales of tobacco products to people under age 21. The American Heart Association is an advocate of Tobacco 21," Jacobs said.
"This is a very important study, both because it has data from multiple countries and because it has been able to follow individuals into middle age, a critical observation. It re-emphasizes the importance of keeping tobacco products out of the hands of children before age 21 to prevent long-term addiction," said Rose Marie Robertson, M.D., FAHA, deputy chief science and medical officer for the Association and co-principal investigator of the American Heart Association's Tobacco Center for Regulatory Science, who was not involved in this study. "Vaping products had not been introduced at the time these study participants were teens, but it is plausible that the findings may relate to vaping as well, since both addiction to nicotine and the adverse effects of nicotine on the developing brain in youth are relevant to these nicotine delivery devices as well."