The Folate Debate
Powers, Mike, Human Ecology Forum
Folate deficiency in pregnant women can cause birth defects in their children. For some women, the deficiency is a result of improper diet. But for others a cellular metabolism problem is the culprit. Professor Patrick Stover's research in folate metabolism may lead to methods to reduce folate deficiency.
In February 1996 the U.S. Food and Drug Administration declared that beginning in 1998 folic acid will be include in the list of nutrients that are added to Americans' food by food manufacturers.
The reason? Insufficient levels of folate in pregnant women increase the risk of birth defects of the head and spinal cord. These deformities, called neural tube defects, include spina bifida, a condition in which part of the spinal cord remains outside the body, and anencephaly, in which the skull and brain fail to form completely. There is also some recent evidence that folate deficiency may be associated with facial deformities such as cleft palate.
Approximately 3,000 children are born with neural tube defects every year in the United States. Children born with spina bifida may have paralyzed legs, develop bowel and bladder control problems, and be confined to a wheelchair. About 30 percent have some degree of mental retardation. Children with anencephaly are stillborn or die soon after birth. The FDA feels that half these births are the result of folate deficiency in the mothers.
According to Division of Nutritional Sciences assistant professor Patrick Stover, the subject of all this concern is a common B-vitamin that plays a major role in our health and physical development.
"Folate allows cells to grow at a rapid rate, so it's extremely important for pregnant women," says Stover, who conducts research on folic acid metabolism. He adds that insufficient levels of folate have been linked to other problems, including cardiovascular disease and cancer.
"This is because so many reactions at the cellular level are dependent on folate. Therefore, you can get a range of pathologies associated with folate deficiency."
Folate was first discovered in the late 1930s and was immediately recognized as being critical to cell proliferation. Chemically, it acts as a catalyst for the creation of DNA and proteins, which in turn are necessary for cell division. Not only does folate play a critical role in fetal development, it is also required for the growth of cancerous tumors. Stover says that within two years of the discovery of the structure of folate, antifolates - drugs that function as antagonists to the vitamin - were created that turned out to be successful anticancer agents.
Folate is readily available in most foods. It's found at the highest levels in beans and peas and is also high in many vegetables and a number of fruits. Some breakfast cereals also are excellent sources. Breads and grains have smaller but still significant levels of folate. Even fast foods like breakfast sandwiches and convenience foods like powdered instant breakfasts are good sources of the vitamin.
One problem with naturally occurring folate, says Stover, is that it's very unstable and can be destroyed during cooking. For this reason, it's important to eat a lot of raw fruits and vegetables. Synthetic folate (folic acid), however, which will be used to supplement food products, is quite stable and can withstand cooking. The FDA plan calls for adding folic acid to enriched breads, flours, corn meals, pastas, rice, and other grain products.
The goal of the fortification program is to ensure that all women of childbearing age (the U.S. Public Health Service puts women ages 15 to 44 in this category) consume at least 0.4 milligram, but no more than 1.0 milligram, of folic acid each day. The one exception is women who have already had a child with a neural tube defect, who are urged to take 4.0 milligrams a day. The decision to target all women was made because neural tube defects occur in the first few weeks of pregnancy, before most women even know they're pregnant. …