Vitamin C may help unborn of mothers who smoke

May 2 2005

Thousands of babies born to mothers who continue to smoke throughout pregnancy despite physician warnings may benefit from new research which suggests that high doses of vitamin C may have the potential to counteract some negative impacts of smoking in unborn babies.

Researchers in the Division of Neuroscience at the Oregon National Primate Research Center conducted a study of infant monkeys born to mothers who were given regular doses of nicotine which were comparable to those of a smoking human mother. The breathing abilities and lung development of these infant monkeys was then compared with monkeys born to mothers who had received both nicotine and vitamin C doses during pregnancy. A third group of baby monkeys that did not receive either nicotine or vitamin C during prenatal development were studied as a control group.

They found that animals exposed to nicotine prior to birth had reduced air flow in the lungs compared to animals that were given nicotine and vitamin C whose lung air flow was closer to that of a normal animal, and found that increased levels of surfactant apoprotein B protein normally caused by nicotine were reduced by vitamin C and elastin levels in the lungs appeared to be slightly impacted by vitamin C. This finding may be quite important as elastin plays a key role in the expansion and contraction of lung during breathing.

Eliot Spindel, M.D., Ph.D., a scientist at the research center and senior author of the paper says the findings of the research are highly applicable to humans, as the sad reality is that approximately 11 percent of pregnant mothers continue to smoke during pregnancy which translates to about a half a million American women a year. It is a chilling reflection of the highly addictive nature of smoking that pregnant women continue to smoke despite the warnings of their physicians and despite a tremendous public awareness campaign aimed at preventing smoking during pregnancy. Spindel says that while this research finding may assist the babies of these mothers, it does not make smoking during pregnancy any more acceptable and should only be a last resort measure.

Smoking during pregnancy can cause premature delivery, growth retardation and has been blamed for 5 percent to 10 percent of all foetal and neonatal deaths. Maternal smoking can also cause decreased pulmonary function and increased respiratory illness in offspring.

Previous research by Spindel has shown that nicotine is a key cause of lung development problems because nicotine crosses the placenta where it interacts with cells in the unborn infant's developing lungs.

Michael Gravett, M.D., chief of maternal-foetal medicine in the Department of Obstetrics and Gynaecology, OHSU School of Medicine, and a researcher at ONPRC, says that smoking remains a very significant problem during pregnancy and infancy and strongly encourages all women to quit smoking.

The researchers caution that while the research demonstrates vitamin C's promise for counteracting the effects of nicotine on lung function it did not counteract other negative health impacts of smoking during pregnancy such as abnormal brain development and decreased body weight, and say more research is needed in regard to determining the appropriate vitamin C dosage for humans and to confirm that giving pregnant women higher levels of vitamin C will not in itself cause development problems.

The ONPRC is a registered research institution, inspected regularly by the United States Department of Agriculture. It operates in compliance with the Animal Welfare Act and has an assurance of regulatory compliance on file with the National Institutes of Health. The ONPRC also participates in the voluntary accreditation program overseen by the Association for Assessment and Accreditation of Laboratory Animal Care International (AAALAC).

The research is published in the current edition of the American Journal of Respiratory and Critical Care Medicine.

http://www.ohsu.edu/