The Canadian policy of fortifying grain products with folic acid has already proved to be effective in preventing neural tube defects. New research published in the British Medical Journal by a group of researchers from the McGill Adult Unit for Congenital Heart Disease (MAUDE Unit), the Research Institute of the McGill University Health Centre (MUHC) and McGill University, shows that folic acid also decreases the incidence of congenital heart defects by more than 6%.
According to Raluca Ionescu-Ittu, a PhD candidate on the team, "this decrease is very significant and probably underestimated. During the study period, there was an increase in other factors associated with a higher prevalence of congenital heart defects, so without the fortification we would probably have seen an increase in these defects."
Since December 1998, all grain products sold in Canada have been fortified with folic acid with 0.15 mg of folate per 100 g of flour. Thanks to provincial databases, the researchers showed that the rate of congenital heart defects between 1999 and 2005 was 1.47 per 1000 births compared to 1.64 per 1000 births between 1990 and 1999 for a decrease of 6.2% per year after 1999.
Despite the success of this initiative, prevention efforts are still necessary to encourage future mothers to take folic acid supplements. "The level of fortification was established to avoid negative side effects in the general population," explained Ms. Ionescu-Ittu. "However, this level is not quite sufficient for women planning a pregnancy, who should start taking folic acid supplements at least three months before becoming pregnant."
Researchers are constantly assessing the beneficial effects of folic acid on the various aspects of embryonic and infant development. Natural sources of the vitamin, such as fruit or green vegetables, might not provide sufficient doses for pregnant women. Most gynecologists therefore recommend supplements in addition to a healthy diet rich in folic acid.
This study was financially supported by the Fonds de recherche en santι du Quιbec and the Heart and Stroke Foundation.
The study was conducted by Raluca Ionescu-Ittu, McGill University; Dr. Ariane J. Marelli, MAUDE Unit. MUHC and McGill University; Dr. Andrew S. Mackie, University of Alberta; and Dr. Louise Pilote, MUHC and McGill University.
- Raluca Ionescu-Ittu, Ariane J Marelli, Andrew S Mackie, and Louise Pilote. Prevalence of severe congenital heart disease after folic acid fortification of grain products: time trend analysis in Quebec, Canada. BMJ, 2009; 338 (may12 2): b1673 DOI: 10.1136/bmj.b1673
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