Largest Canadian folic acid study confirms benefit to babies

Since they were introduced nearly 10 years ago, food products fortified with folic acid have helped cut the rate of spina bifida and other birth defects in half, according to a new study.

Since they were introduced nearly 10 years ago,food productsfortified with folic acid have helped cut the rate of spina bifida and other birth defectsin half, according to a new study.

Dark green, leafy produce, like broccoli, is a good dietary source of folic acid. ((Richard Drew/Associated Press))

The prevalence of neural-tube defects— birth defects of the brain and spinal cord— has decreased from 1.58 per 1,000 births to 0.86 since Canada made folic-acid fortification mandatory in 1998, a study published in the New England Journal of Medicine reported on Thursday.

It is the largest study undertaken to determine the impact ofCanada'sfortification programon developing fetuses. Researchers collected data on almosttwo million pregnancies from hospitals in seven provinces to observe changing rates of neural-tube defects between 1993 and 2002. A total of 2,446 subjects with such defects were recorded among 1.9 million births.

Researchersdiscovered a 46 per cent overall reduction, and a 53 per cent reduction in spina bifida cases specifically. The decline in prevalence wasmost noticeablein the Atlantic provinces, where neural-tube defects were historically highest.

The greatest success with folic acid fortification occurred in Newfoundland and Labrador, where birth defect rates plunged to 0.76 per 1,000 from 4.56 per 1,000 after the B-vitamin was added to products like bread, cereal and pasta.By 2002,a traditionally higher rate therehad caught up to that of British Columbia, which fell from 0.96 to 0.75 per 1,000 births after mandatory fortification.

"This [geographic] gradient almost disappeared after fortification," said lead author Philippe De Wals, a professor of social and preventive medicine at Laval University in Quebec. "Now we get the explanation. It was not a genetic factor, but it was folate deficiency."

He attributed the old regional disparity to Maritime eating habits, which he said were comparable to those of the U.K., where peopledestroy the folic acid in their food by boilingvegetables and meat for hours.

"That type of cooking is not so prevalent in the West."

Women take folic acid before and during pregnancy to prevent spine or brain defects that develop in the first few weeksafter conception. Folic acid is the synthetic form of folate, also called vitamin B-9, which is found in citrus fruits, nuts, liver and dark green, leafy vegetables. Itcreates healthy new cells that help form a baby's brain, spine, organs, skin and bones.

Medical authorities began campaigns in the 1990s to tell women of child-bearing age to take folic acid supplements, and in 1998 the Canadian government ordered grain products such as flour, breakfast cereals and pasta to be fortified with the synthetic form of folate.

With files from the Canadian Press