Study links folic acid fortification with decline in congenital heart defects

Food fortified with folic acid is associated with reduced rates of congenital heart defects, according to Canadian research.

“Our study examined the effect of folic acid food fortification on each specific subtype of congenital heart disease based on the Canadian experience before and after food fortification was made mandatory in 1998,” said KS Joseph, MD, PhD, the study’s senior author and professor in the Department of Obstetrics and Gynecology and the School of Population and Public Health at the University of British Columbia in Vancouver, Canada.

The researchers analysed data from nearly 6 million Canadian births from 1990 to 2011 and found that folic acid food fortification was associated with an 11% reduction in rates of congenital heart defects overall.

They found that the beneficial effects of folic acid were evident in some subtypes of congenital heart defects, including: 27% reduction in conotruncal defects, or severe heart outflow tract abnormalities; 23% reduction in coarctation (narrowing) of the aorta; and a 15% reduction in atrial and ventricular septal defects — holes in the wall separating heart chambers. However, no changes were seen with regard to chromosomally associated defects.

In 1988, Canada mandated adding folic acid to all types of flour, enriched pasta and cornmeal, primarily aimed at preventing neural tube defects. Folic acid is especially important for rapid cell division and growth — for instance, when blood is being formed and in pregnancy when the foetus is growing rapidly.

Folate deficiency can result in several different complications — the most important of these are neural tube defects (such as spina bifida, an abnormality of the spine and spinal cord) in babies and anaemia.

The results of the study have been published in the American Heart Association’s journal Circulation.