A new study shows that the incidence of neural tube defects in Canada has dropped by 46 per cent since the country began adding folic acid to flours. Support for the benefits of folic acid seems to be coming in all the time.
The new study, published in the New England Journal of Medicine, has implications for countries debating the effectiveness of adding this ingredient to flour. Currently, only Canada, the United States, and Chile require that folic acid be added to flour, but the signs seem to indicate that it will be introduced in other countries soon. An announcement is expected within the next month in Ireland, and similar measures are under scrutiny in Australia.
Author Philippe De Wals of Université Laval and his colleagues found that food fortification with folic acid was associated with a significant reduction in neural-tube defects in Canada. "Furthermore, the risk reduction appeared greatest in regions in which the rates were highest before the fortification program was implemented," he writes in NEJM.
Folate is found in foods such as chick peas and lentils as well as green leafy vegetables, and a large body of evidence links now links folate deficiency in early pregnancy to increased risk of neural tube defects. These are most commonly spina bifida and anencephaly, which occur in infants.
Since 1997, public health measures in Canada (the US followed suit a year later) have all grain products fortified with folic acid - the synthetic, bioavailable form of folate.
"Canada decided to add folic acid to all flour produced in the country because formation of the neural tube in embryos is particularly intense during the first four weeks of pregnancy, which is before a lot of women even know they're pregnant. Since half of pregnancies are unplanned and the human body can't store folic acid, it is better to integrate folic acid into the food chain than to focus exclusively on taking vitamin supplements," say the authors.
The researchers compared the incidence of neural tube deformations before and after the introduction of folic acid-enriched flours for over 2 million births in Canada. Between 1993 and 1997, the incidence was 1.58 per 1,000 births. Between 2000 and 2002, the rate dropped 46 per cent to 0.86, showing the effectiveness of adding folic acid to foods.