WEDNESDAY, July 11, 2007 (HealthDay News) -- After the Canadian government mandated the addition of folic acid to flour-based foods in 1998, the rate of neural tube birth defects dropped 46 percent, new research shows.
That tops the 28 percent reduction seen in such defects after a folic acid fortification program was implemented in the United States that same year.
"In the field of prevention, there have been a few clear triumphs of science and public health interventions -- immunization programs, when iodine was added to salt, and when vitamin D was added to milk. Now, we have another major victory in that we can prevent major and severe birth defects in children. Neural tube defects are a tragedy, and this is really a major public health victory," said study author Philippe De Wals, head of the department of social and preventive medicine at Laval University in Quebec. "All countries should adopt folic acid fortification."
The potential to prevent neural tube defects from occurring in the first place is why other countries have mandated the addition of folic acid to breads, cereals and pastas. Because folic acid -- a B vitamin -- is water-soluble, it doesn't collect in the body's tissues and isn't considered harmful to the general population. The only concern about additional folic acid is that it may mask symptoms of a vitamin B-12 deficiency in the elderly.
Beginning in 1998, the Canadian government began requiring folic acid fortification. According to the study, it's estimated that fortification added an average of about 150 micrograms of daily folic acid to each Canadians' diet. The recommended daily amount to prevent birth defects is 400 micrograms daily.
When the spinal cord or brain doesn't develop properly in early pregnancy, it's known as a neural tube defect. The most common neural tube defects are spina bifida and anecephaly. These birth defects affect about 3,000 American babies each year. Spina bifida occurs when the spinal column doesn't close properly and often results in lifelong disability. In anecephaly, the brain and skull bones don't form normally, and often part of the brain and skull is missing. These babies usually die soon after birth.
Up to 70 percent of these defects could be prevented if all pregnant women got the daily recommended amount of folic acid prior to conception and in the early weeks of pregnancy, estimates the U.S. Centers for Disease Control and Prevention.
To assess the effect the fortification had on the birth defect rate, which was higher in Canada than in the United States, De Wals and his colleagues examined birth records -- both before and after fortification -- for almost 2 million women from seven Canadian provinces. In that group, there were 2,446 babies born with neural tube defects.
The researchers found that before fortification the prevalence of neural tube defects was 1.58 per 1,000 births. After folic acid fortification, that number plummeted to 0.86 per 1,000 births -- a drop of 46 percent.
Prior to fortification, Canada had widely varying rates of neural tube defects, with most of cases occurring in the eastern area of Canada. Before folic acid was added to the food, Newfoundland and Labrador had rate of neural tube defects as high as 4.56 births per 1,000 births, while across the country to the west, British Columbia's rates were only 0.96 per 1,000 births.
After fortification, those differences evaporated, suggesting that a folic acid deficiency in the east was the reason for the geographical disparity.
Dr. Robert Lorenz, director of maternal-fetal medicine at Beaumont Hospital in Royal Oak, Mich., said he wasn't surprised that Canada's rate dropped more significantly than it did in the United States. "They had higher rates of neural tube defects to begin with; I would expect the two to go together," he said.
De Wals said another reason may be that manufacturers in Canada may add slightly more folic acid than they're required to, because it's a very low-cost product. "It didn't add a penny to the cost of bread," he said.
The savings, however, are dramatic. "For every dollar invested in fortification, probably about $100 will be saved in the care of children with spina bifida," De Wals said.
"The benefit of folic acid fortification comes from the fact that about half of all pregnancies in the U.S. are unplanned," said Lorenz. But, he added that folic acid fortification doesn't mean women don't' have to make an effort to eat right during pregnancy and beyond.
"A healthy diet that includes vitamins and minerals is critically important for reproductive health and also for cardiac health and to reduce the risk of diabetes and more," Lorenz noted.
Additionally, De Wals pointed out that folic acid fortification in foods will likely eradicate folic acid deficiency anemia, and researchers are learning that the additional folic acid may provide other benefits, such as a reduced mortality from stroke.
More information
To learn more about folic acid, visit the U.S. Centers for Disease Control and Prevention.
