A public health initiative to enrich cereal grain foods in Canada with folic acid has halved the prevalence of neural-tube defects among both unborn and newborn children, report authors of a research letter in this week's issue of The Lancet.
Folic acid tablet supplementation around the time of conception is known to dramatically reduce the risk of neural-tube defects (affecting the brain and spinal cord) in unborn infants.
In 1998 Canada introduced folic acid fortification of grain foods, increasing daily folate in the Canadian population by 0.1-0.2 mg per day, in response to concern that women were not taking tablet supplements until after they had become pregnant, or not at all.
Joel Ray and colleagues from Sunnybrook and Women's College Health Sciences Centre and North York General Hospital, University of Toronto, Canada, assessed the effect of food fortification on the prevalence of open neural tube defects in the province of Ontario. Around a third of a million women were screened for foetal neural tube defects over six years before and after the grain fortification policy was introduced. The risk of neural tube defects was halved from around 1.13 to 0.58 per 1000 births after fortification was fully introduced.
Joel Ray commented: "Even under quite suitable conditions, neural tube defect prevention programmes based solely on periconceptional folic acid tablet supplementation seem to fall far short of achieving their potential effectiveness. On the basis of our results, and those of others, we recommend that other countries consider adopting a programme of folic-acid food fortification, in addition to encouraging increased use of periconceptional folic acid tablets."
He added that the population could also be monitored for any side effects related to folic acid fortification and to allow for modification of the programme as necessary.
The fortification debate has been vigorous in the UK in the last year, with the Food Standards Agency deciding not to recommend the initiative on the grounds that not enough was known about the potential adverse effects. No other European countries have adopted the policy.