FDA muffed chance to reduce birth defects
Front-page headlines last week trumpeted news of the US Food and Drug Administration's ban of the dangerous food supplement, ephedra. But it's important not to forget that the same agency's misguided decisions have hampered efforts to solve a problem that harms more babies than any other birth defect. More American children are born with this condition than with HIV infection. Surprisingly, one in 20 unsuspecting American adults have mild, subclinical forms of the disease, having narrowly escaped a lifetime of paralysis and incontinence. What's more, this disease -- spina bifida -- could be largely prevented if it weren't for a modern-day public health myth fostered by the FDA.
Superstition about spina bifida isn't new. Thirty years ago, when my cousin Jayesh was born in Bombay, the obstetrician noticed a strawberry-like protrusion on the newborn's
back. The baby's spine had failed to develop normally, and most of the nerves to his leg and bladder didn't work. I often overheard my relatives speculating about his mother's spiritual wrongs; why else, they wondered, would her child's spine be deformed? Thankfully, the boy didn't require brain surgery and wasn't mentally retarded, like many children with spina bifida. Still, he couldn't walk well, or urinate or move his bowels without aid. In the city of Jayesh's birth, chemist Lucy Wills took the first steps on the long path toward enlightenment about spina bifida. She studied a curious form of "pernicious anemia" that occurred late in pregnancy and spontaneously improved after a baby's delivery. In 1931, Wills found that eating Marmite, a yeast extract like Australian vegemite, cured the anemia before delivery.
In the 1940s, a biochemist at the University of Texas isolated a new vitamin from spinach called folic acid, after the Latin folium for leaf. This was the mysterious vitamin in Marmite that cured pernicious anemia of pregnancy, which affected 25 percent of pregnant women. Two decades later, an astute obstetrician noted that most women delivering children with spina bifida had the anemia. He correctly hypothesized that folate deficiency could cause these birth defects.
Two large studies in 1992 proved that folic acid could reduce the number of cases of spina bifida by 50 to 70 percent. Within a year, the Centers for Disease Control and Prevention recommended that all women of childbearing age take a daily folic-acid supplement.
What then occurred was a public health failure. The prevention of neural tube defects should have galvanized authorities. In the words of Dr. Robert Brent, a prominent researcher at Jefferson Medical College, "folic-acid-sensitive birth defects are as preventable as polio." But Brent noted that every year in the United States more children are still born with preventable spina bifida than were deformed by thalidomide at the height of the European epidemic. It's a continuing public health emergency.
We know how to prevent spina bifida, but why can't we actually do it? The problem is that, at least in the United States, half of all pregnancies are unplanned, and by the time women realize they're pregnant and start taking folate, the fetus has already developed a spinal column and any associated defects. So, the CDC recommends that women take a daily folate supplement during their childbearing years, but few do so, believing that a daily pill is a hassle if they're not trying to conceive.
An interesting solution was proposed: Why not simply add folic acid to flour, a key food that everyone eats in some form? Similar approaches have prevented thyroid goiter (by adding iodine to salt), cavities (by adding fluoride to water), and rickets (by adding vitamin D to milk). After mulling over the issue for four years -- during which time thousands of preventable cases of spina bifida occurred -- the FDA finally ordered that all enriched grain products be fortified with folic acid by 1998.
Unfortunately, and this was the FDA's folly, the chosen dosage is too small. Against the recommendations of the American Academy of Pediatrics and other health organizations, the FDA required enough folic acid to furnish only one-fourth of the amount needed to prevent spina bifida. On average, the proportion of women getting enough folate increased by only 3 percent. Researcher Godfrey Oakley of Emory University compared the decision to "marketing polio vaccine containing only the least common of the three vaccine strains." Studies later found that national rates of spina bifida dropped only a fraction of what they could have. That is, thousands of children with Jayesh's problem are still born today.
The FDA chose inadequate supplementation for a curious reason. All people, not just pregnant women, are exposed to enriched flour. The agency subscribed to the unproven and theoretical belief that adequate folic acid in elderly people's diets might unwittingly treat a type of anemia caused by vitamin B12 deficiency. While the anemia of these people might improve, other problems such as dementia and spinal cord problems (that improve only with vitamin B12 and not folate) might continue undetected. The FDA argued that leaving elderly people anemic was critical so that they would at some point -- presumably due to symptoms of anemia, such as fatigue or passing out -- come to the attention of a doctor and get treated with vitamin B12.
Plainly stated, the FDA chose to allow thousands of babies to be born with deformed spines rather than overcome the superstitions surrounding folic acid. In 1998, the prestigious Institute of Medicine indicated that doses up to 10 times higher than allowed by the supplementation campaign were safe. An article in the New England Journal of Medicine stated that "had [this data] been available earlier, flour might have been fortified at a higher level." Nevertheless, no change has since been made.
In the absence of adequate fortification, you'd think that a well-funded media campaign would encourage women of childbearing age to take folic acid pills daily. You'd be wrong. The Clinton administration failed to ask Congress for any money for the CDC to run an effective public education program. A March of Dimes survey found that women taking folic acid-containing vitamins daily increased from 25 percent in 1995 to only 31 percent in 2002. The same year, according to the CDC, 10 percent of physicians didn't know that folic acid prevents spina bifida.
America's children have waited long enough for action. For thousands of children each year born like Jayesh, health delayed is health denied. It's about time our public health authorities stopped looking the other way and started taking responsibility for these kids.
Dr. Darshak Sanghavi, a pediatrician and clinical fellow at Children's Hospital and Harvard Medical School, can be reached at darshak.sanghavi@childrens.harvard.edu.
