Kids get more cavities when they live with smokers, says Japan study

Young children are much more likely to get cavities if they live in a household with smokers, a Japanese study suggests.

Compared to children in non-smoking households, kids living with smokers were more than twice as likely to have cavities at age three.

Even when smokers in the home didn’t light up near the children, these three-year-olds were 50 percent more likely to have cavities than kids who didn’t live with smokers, the study found.

The findings should give parents another reason to quit smoking, and another way for health care providers to talk to them about cessation, said senior author Koji Kawakami, a researcher at Kyoto University in Japan.

“Education on the harm of secondhand smoke might increase if dentists became aware of the risk of [cavities] as well as tobacco consumption of their clients,” Kawakami said by email.

To understand the connection between secondhand smoke and cavities, Kawakami and colleagues examined data on almost 77,000 children born between 2004 and 2010 in Kobe City, Japan.

To be included in the study, children needed data on household smoking status when they were infants, as well as records from dental exams done at 18 months and three years.

Overall, about 55 percent of the children lived in households with smokers, but only about 7 percent had people who smoked around them instead of lighting up somewhere away from the kids.

By age three, 14 percent of the kids in non-smoking households had cavities, compared with 20 percent of children who had smokers in the home who tried not to use cigarettes in their presence, and 28 percent of kids who were directly exposed to the smoke.

Children of women who smoked during pregnancy didn’t appear to have an increased risk for cavities, the authors reported in the medical journal BMJ.

One limitation of the study is that it relied on mothers to honestly report smoking in the home on questionnaires, the authors acknowledge. In particular, women may have underreported smoking during pregnancy.

In addition, because the study was observational, and didn’t randomly assign groups of children to live with or without smokers, the findings can’t prove that smoke exposure causes cavities.

Two things in Japan—lack of fluoride in the water and less sugar in a typical diet—might make results for these children different than what researchers might see in the US and other countries, where children consume more sweets and have fluoride-enhanced drinking water, the authors also note.

But the connection between cigarette exposure and cavities is strong enough that the US Surgeon General has warned that secondhand smoke may be associated with an increased risk of tooth decay in children.

“This study simply adds to the body of evidence that associates secondhand smoke and an increased risk of tooth decay among children,” said Jonathan Shenkin, a researcher in pediatric dentistry at Boston University and a spokesperson for the American Dental Association.

“Tooth decay is the most common chronic disease in childhood,” Shenkin, who wasn’t involved in the study, said by email. For parents, “knowing they can protect their children against pain and suffering will hopefully be a strong motivator to quit smoking.” — Reuters -

Young male smokers may raise obesity risk in their future sons

LONDON - Men who start smoking before the age of 11 risk having sons who are overweight, British researchers have found, adding to evidence that lifestyle factors even in childhood can affect the health of future offspring.

The scientists said the findings, part of ongoing work in a larger "Children of the 90s" study, could indicate that exposure to tobacco smoke before the start of puberty in men may lead to metabolic changes in the next generation.

"This discovery of transgenerational effects has big implications for research into the current rise in obesity and the evaluation of preventative measures," said Marcus Pembrey, a professor of genetics at University College London, who led the study and presented its findings at a briefing on Wednesday.

Smoking rates in Britain and some other parts of Europe are on the decline, but worldwide, almost one billion men smoke - about 35 percent of men in developed countries and 50 percent in developing ones, according to the World Health Organization.

While previous studies in animals and in people have found some transgenerational health impacts, the evidence so far is limited. It points, however, to epigenetics - a process where lifestyle and environmental factors can turn certain genes on or off - having an effect on the health of descendants.

Pembrey said his team's research was prompted in part by signals from earlier Swedish studies that linked how plentiful a paternal ancestor's food supply was in mid childhood with future death rates in grandchildren.

For the new study, published in the European Journal of Human Genetics, the researchers had access to detailed lifestyle, genetic and other health data from 9,886 fathers.

Of these, 5,376, or 54 percent, were smokers at some time and of those, 166, or 3 percent, said they had started smoking regularly before the age of 11.

Looking at the next generation, the team found that at age 13, 15 and 17, the sons of men who started smoking before 11 had the highest Body Mass Index (BMI) scores compared with the sons of men who had started smoking later or who had never smoked.

"These boys had markedly higher levels of fat mass - ranging from an extra five kilograms (kg) to 10kg between ages 13 and 17," the study said.

Although it was there, the effect was not seen to the same degree in daughters.

External experts not involved with the research were more guarded about drawing firm conclusions from its findings.

Graham Burdge, an expert in human nutrition at the University of Southampton said the findings "may potentially provide new insights into factors that may influence development of obesity in childhood".

"However, the findings only show associations and cannot be interpreted as indicating that paternal smoking at an early age causes obesity in their sons," he added.

Tim Spector, a professor of genetic epidemiology at King's College London, said the findings were intriguing and rare.

"The data are persuasive but not yet definitive as we need to confirm the same smoking related epigenetics changes in the kids' DNA," he said. — Reuters

source: gmanetwork.com