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May 25, 2006 -- A new study shows that 11-year-olds who smoke just one cigarette are more likely to become regular smokers by the time they're 14 years old.
"It may be that preventing children from trying even one cigarette is an important goal, and prevention efforts could usefully be focused at the earliest ages," write University College London's Jennifer Fidler, PhD, and colleagues.
Fidler's team also writes that one-time smoking may have a "sleeper effect," or a period in which youths who have smoked one cigarette may be particularly vulnerable to becoming regular smokers.
The study comes on the heels of a CDC report showing that, worldwide, nearly two in 10 students aged 15-17 years report currently using a tobacco product (9% are cigarette smokers; 11% use other tobacco products). Those figures are published in the CDC's Morbidity and Mortality Weekly Report.
Young Novice Smokers
Fidler and colleagues studied more than 5,800 students from 36 London schools.
The study started when the students were 11 years old and ended when they were 16. The group was diverse in terms of ethnicity and income.
Every year, the students completed surveys about whether they had ever smoked and, if so, how often they smoked. They also provided saliva samples that were tested for cotinine, a chemical marker of nicotine.
The students didn't have to participate in any of those tests. About a third had complete data for all five years; Fidler's team focused on those 2,041 students.
When those students were 11 years old, 206 reported having smoked just one cigarette. They were twice as likely to start smoking regularly by age 14 than their peers who reported never smoking cigarettes at age 11.
'Sleeper' Effect
"Our results show that progression from experimenting with one cigarette (being a "one-time trier") to current smoking can take up to three years," write Fidler and colleagues.
"However, we have also shown that, between trying an early cigarette and regular smoking uptake, there may be a protracted period of dormancy when no reported smoking occurs," they continue.
The researchers suggest that that dormancy "may be termed a 'sleeper effect,' a personal propensity or vulnerability to smoke that may not become manifest without additional triggers."
The reason for that effect isn't clear, note Fidler and colleagues. They suggest three possible explanations:
Study's Limits
The researchers note some limits to their study.
Only adolescents took part, so the data doesn't show if the findings apply to adults.
Also, the students may not have reported their smoking habits accurately. However, Fidler's team notes that previous studies have shown that adolescents are generally reliable in reporting their smoking habits.
Fidler's team also isn't sure that the findings apply to other groups of students, though they point out that their group was socially and ethnically diverse.
Finally, the study doesn't look at younger kids. It's possible that the "sleeper" period might start earlier than age 11.
Further studies of younger children and young adults would help clarify how some youths progress from one-time smokers to regular smokers, note Fidler and colleagues.
SOURCES: Fidler, J. Tobacco Control; June 2006, vol 15: pp 205-209. CDC, Morbidity and Mortality Weekly Report, May 26, 2006; vol 55: pp 553-556. News release, BMJ Specialist Journals. News release, CDC.