MONTREAL — Fortification of flour, pasta and other grain products with folic acid, already shown to reduce neural tube birth defects, also may prevent congenital heart defects, according to a study from researchers at the McGill Adult Unit for Congenital Heart Disease, the Research Institute of the McGill University Health Centre, and McGill University.
The research, published in the May on-line edition of the British Medical Journal, showed folic acid decreases the incidence of heart defects by more than 6%. Since December 1998, all grain products sold in Canada have been fortified with folic acid with 0.15 mg of folate per 100 grams of flour.
"This decrease is very significant and probably underestimated," said Raluca Ionescu-Itt, lead researcher. "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."
As part of the study, researchers collected date on 1.3 million births in Quebec between 1990 and 2005. During that period, 2,083 children were born with heart defects, an average of 1.57 for every 1,000 births. Broken down to reflect folic acid fortification, the average rate was 1.64 defects per 1,000 births between 1990 and 1999 (pre-fortification), versus 1.47 defects per 1,000 births between 1999 and 2005 (post-fortification), working out to a 6.2% decrease in defects per year after 1999.
Despite the success of Canada’s folic acid initiative, researchers in the study urged a higher level of consumption for women considering becoming pregnant.
"The level of fortification was established to avoid negative side effects in the general population," Ms. Ionescu-Ittu said. "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."The study was financially supported by the Fonds de rechereche en santé du Quebec and the Heart and Stroke Foundation.