Teens whose parents have ever smoked are more likely to become smokers, even if their parents quit before they were born, according to a new study. Teens with an older sibling who smokes are also more likely to start using cigarettes.

The study followed 214 participants starting in 1988, when they were high school freshmen, until 2011. The researchers also studied 314 of their children ages 11 and older. Participants took annual surveys about their smoking habits, and their children were surveyed in 2011.

The researchers found in homes with a parent who was a persistent heavy smoker, the oldest sibling was influenced to smoke, which increased the odds that young siblings would also smoke by six times, HealthDay reports.

“These findings imply that any amount of smoking could have important influences on the next generation,” said lead researcher Mike Vuolo of Purdue University. “Given the influence on the oldest siblings, this is especially the case in heavy-smoking households.”

The study found a smoking rate of 23 percent among children whose parents started smoking as teens and who had quit or cut back on their smoking by age 38. Among children whose parents started smoking in their 20s, the smoking rate was 29 percent. The smoking rate among children whose parents had never smoked was 8 percent.

“Based on these findings, antismoking prevention for youth really needs to target the children of parents who smoked at any time in their life, as well as if siblings are smoking,” Vuolo said in a news release.

The findings appear in Pediatrics.