(Reuters Health) - Two consecutive generations of children in the UK had dramatically different rates of smoking at an early age, and one major reason may be the changing socioeconomic status and behaviors of their parents and friends, researchers say.

Children born in 1970 were 12 times more likely to have smoked a cigarette by age 10 or 11 compared with kids born in the early 2000s, the study team reports in the journal Addictive Behaviors.

Changing risk factors for early smoking, including mother’s education level and whether the child had any friends who smoked, may explain some of the difference between these two generations of UK kids, they write.

“(The study) highlights the importance of addressing social determinants of health, as outlined by the WHO and other scholars, as a means to reduce the burden of health risk behaviors in our society,” said Kelvin Choi of the U.S. National Institute on Minority Health and Health Disparities in Bethesda, Maryland, who was not involved in the research.

The study team, led by Jeremy Staff of Pennsylvania State University in University Park, analyzed data on two large groups of UK children. One group was made up of all children born during one week in April 1970, the other included kids born between late 2000 and early 2002.

A total of 23,506 kids answered questionnaires at ages 10 or 11. The researchers also had data about the children’s parents, including educational and smoking history as well as household income.

Overall, 14.5 percent of the kids born in 1970 had smoked at least one cigarette by age 10-11, while that was true for only 2.4 percent of the later generation.

In addition, while 14 percent of the kids born in 1970 had a friend at age 10-11 who smoked, just 5 percent in the later generation did.

Another dramatic difference between generations involved the children’s mothers: in the older generation, 57 percent of mothers had no higher education; in the newer generation, that had fallen to 8 percent. In addition, about 43 percent of the mothers of the older generation were smokers themselves when their child was 5 years old, and that had fallen to 33 percent for the younger generation.

The results represent “dramatic changes in the risk factors associated with childhood smoking,” write the authors, who were not available to comment.

In the earlier generation, a mother’s education level did not predict whether the child would smoke by age 10, but children in the later generation were 40 percent less likely to smoke if their mother had a post-secondary education compared with kids whose mothers did not.

While the overall drop in early smoking from one generation to the next is “cause for celebration,” the authors write, the results also highlight the fact that “childhood smoking in today’s young people in the UK is now more strongly linked to early life disadvantages compared to a generation ago.”

“I think the results of this study are really important because they reinforce the research that has been emerging to help us understand disparities in smoking in low income communities,” said Vaughn Rees, director of the center for global tobacco control at Harvard T. H. Chan School of Public Health in Boston.

The prevalence of smoking in adults in the U.S. is close to 15 percent, he noted in a phone interview, but among those adults who live below the poverty line, the prevalence of smoking is about 27 percent, or almost double.

“These rates haven’t changed in 30 years,” said Rees, who was not involved in the current study.

“I think there is no need to double our smoking prevention efforts. We need to think about innovative strategies and new approaches,” he added.

Among the study’s limitations, Choi noted, is that it does not prove whether or how differences in maternal education and parental/peer smoking caused the decline in early smoking among the kids in one generation compared to the other.

SOURCE: bit.ly/2mc3zF0 Addictive Behaviors, online June 12, 2018.