Study shows that folic acid added to flours lowers incidence of congenital neural tube deformation

Jul 13 2007

Dr. Philippe De Wals of Universite Laval's Department of Social and Preventive Medicine publishes a study clearly indicating that the addition of folic acid to flours has led to a 46% drop in the incidence of congenital neural tube deformation (mainly anencephaly and spina bifida) in Canada. Such deformations either result in the child's death or in major health problems, including physical and learning disabilities.

Dr. De Wals's work as head of a team of a dozen Canadian researchers appears today in the New England Journal of Medicine.

The neural tube is the basis of the embryo's nervous system. Poor development of the neural tube, which is sometimes due to a lack of folic acid, can result in major health problems. Folic acid is found in green vegetables, fruit, whole grains, and meat. However, even a balanced diet won't supply enough folic acid for a pregnant mother and the child she is carrying. Before 1998, Canadian medical authorities were already recommending that women in their child-bearing years consume vitamin supplements containing folic acid. "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 Canadian 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," stated Dr. De Wals. Health Canada still recommends taking folic acid supplements to women in their child-bearing years.

Researchers Dr. Philippe De Wals and Fassiatou Tairou of Universite Laval's Faculty of Medicine 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% to 0.86. The biggest improvement occurred in the parts of Canada that had the highest rates of neural tube deformation before 1998, Newfoundland, Prince Edward Island, and Nova Scotia. In Quebec, the drop was also pronounced, but closer to the Canadian average.

Currently, only Canada, the United States, and Chile require that folic acid be added to flour. The effectiveness of this practice, as demonstrated by Dr. De Wals's team, could encourage other countries to follow suit. Every year, approximately 200,000 cases of spina bifida and anencephaly occur worldwide. Adding folic acid to food could reduce that number by half.