Good news for pregnant women who cannot stop smoking - scientists say high doses of vitamin C may have the potential to counteract some of the negative effects that smoking has on unborn babies.
Five to 10 per cent of all foetal and neonatal deaths are blamed on smoking during pregnancy. In the US, about 12 per cent women keep smoking during pregnancy. Over 450,000 smoke-exposed infants are born each year.
Babies are at a risk for premature delivery, growth retardation and death. Maternal smoking can also cause decreased pulmonary function and increased respiratory illness in offspring.
According to researchers at Oregon Health and Science University, babies born to mothers given vitamin C along with nicotine have almost the same lung airflow as non-smoking mothers, reports the Internet portal Register-Guard.
Nicotine is known to be harmful to elastic tissues in the lungs, and it is possible that vitamin C may prevent that harm.
So far, tests have been limited to rhesus monkeys.
Scientists studied three small groups of infant monkeys. Seven monkeys were born to mothers who received two mg doses of nicotine daily, comparable with those of a smoking mother.
Breathing abilities and lung development of those monkeys were compared with seven monkeys born to mothers who had received both nicotine and 250 mg vitamin C daily during pregnancy.
A third group of six monkeys received neither nicotine nor vitamin C and was studied as a control group.
The researchers found that animals exposed to nicotine before birth had reduced airflow in the lungs, compared with animals given nicotine and vitamin C.
Monkeys given nicotine and vitamin C had lung airflow close to that of a normal animal, said Eliot Spindel, one of the senior research scientists.
"The single most important thing is for pregnant women to stop smoking. While this research finding may assist the babies of (smoking) mothers, it does not make smoking during pregnancy more acceptable," Spindel warned.
"It would only become a last resort treatment when an expectant mother is unwilling to stop smoking."
Researchers also observed that increased levels of a protein called surfactant apoprotein B - normally caused by nicotine - were reduced by vitamin C.
While one theory involves vitamin C's role as an antioxidant, protecting molecules in the body from damage by free radicals, another involves the vitamin's effect on connective tissues.