Passive smoke linked to vitamin C depletion in kids
Children whose parents smoke at home have significantly lower levels
of vitamin C in their blood than kids in non-smoking homes, a large
study out Monday shows.
The more parents smoke, the less of the vitamin youngsters have in
their bloodstreams, says Richard Strauss of the University of Medicine
and Dentistry of New Jersey. His report in Pediatrics is the first major
scientific study on how passive smoke affects vitamin metabolism in
children and adolescents. Passive smoke already has been linked to
lower levels of vitamin C in adults.
''Free radicals'' in tobacco smoke -- chemicals that damage human
cells -- oxidize harmful LDL cholesterol, which can clog arteries and
promote heart disease, Strauss says. Vitamin C, an antioxidant, may
become depleted from fighting the free radicals in cigarette smoke,
Figures show 22% of children and teens are exposed to passive
smoke at home.
The new study included 2,968 youngsters ages 4 to 18. Scientists
asked parents about their smoking habits, their children's diet and
supplemental vitamin use.
Among key points:
* No difference in vitamin C intake for kids exposed to passive
smoke and those with non-smoking parents.
* The more cigarettes parents smoked, the higher their child's blood
levels of cotinine, a metabolite of nicotine.
* Smokers' children averaged 20% less vitamin C. The more
parents smoked, the lower their child's store of vitamin C.
Even at the highest levels of depletion, ''they're not deficient to the
point they'll get scurvy,'' Strauss says. ''We don't know how significant
these decreases are or what the long-term effects could be.''
But the findings raise potentially serious concerns, says Fima Lifshitz,
chief of staff at Miami Children's Hospital and an expert in children's
Vitamin C protects not only against heart disease, but also helps
prevent DNA changes linked to some cancers, he says. And low
vitamin levels could combine with other vulnerabilities to induce
illness, Lifshitz says.
Passive smoke has been tied in past scientific studies to higher risk
of childhood asthma, ear infections, respiratory illness and sudden
infant death syndrome. ''Depletion of vitamin C might be related to
these problems,'' he says.
The impact of such vitamin C loss in children merits further study,
Lifshitz says. ''You just can't ignore less-than-optimal levels of a very
important vitamin in kids, especially in view of what we already know
about the negative consequences of passive smoke.''
The study does not prove smoke causes the vitamin loss, says
Vanderbilt University cardiologist Rose Marie Robertson, president
of the American Heart Association.
''But when you get these linear relationships, it's stronger scientifically,
and to have such measurable cotinine levels in children is a dramatic
finding,'' she says.
Pathology studies show arteriosclerosis begins by adolescence,
Parents who smoke may be unaware ''there are much better things
out there now'' to get through withdrawal when quitting, such as
nicotine patches and gums, she says. ''It's easier now than it used
to be,'' Robertson says, ''and I hope more parents will try.''