Folate aids health, but only if used

Research shows benefits, but women fail to get enough of the vitamin

January 13, 2007|By Dennis O'Brien | Dennis O'Brien,Sun Reporter

It's known to prevent birth defects, and the latest studies show it helps retain memory and hearing. But despite a decade-long public health campaign, women still don't get enough of the vitamin folate.

A type of B vitamin, folate is found naturally in beans, leafy vegetables, some meats and orange juice. During the past few weeks, two scientific studies and a federal report have focused interest on what steps may be needed to boost consumption.

"It's a hot topic in the medical literature right now," said Dr. Joseph Mulinare, a pediatrician and epidemiologist at the Centers for Disease Control and Prevention.

He reported in the Jan. 5 issue of the CDC's Morbidity and Mortality Weekly Report that blood folate levels of women between ages 15 and 44 dropped from 1999 to 2004. The decrease of between 8 and 16 percent occurred despite the fortification of many breads and cereals with folate in the form of folic acid.

The numbers were based on health surveys of 4,500 women that included blood samples. They were a reversal of an upward trend resulting from a public health campaign begun in the late 1990s. The CDC spends $2 million a year to encourage young women to take folic acid to prevent birth defects.

Some experts blame the drop in women's folate levels on the popularity of low-carbohydrate diets that discourage consumption of bread. Rising obesity rates might also be a factor because of the way overweight people metabolize folate, experts say.

"We just don't know what it was," Mulinare said.

Although the need for folate is most clearly established for women of reproductive age, all adults are supposed to get 400 micrograms each day from folate-rich foods or those fortified with folic acid.

"It could have a number of benefits, but we just don't know yet," said Jane Durga, a Dutch nutritional epidemiologist whose research shows a positive effect on hearing and memory.

In a 2005 study, Durga gave 818 people between ages 50 and 75 a placebo or 800 micrograms of folate for three years. On memory tests, those who took folate scored comparably to people who were five years younger, she found.

Recent study

In a study published this month, Durga tested 728 subjects between the ages of 50 and 70, who showed signs of age-related hearing loss. They received a placebo or 800 micrograms of folate daily for three years.

Those who took the folate experienced 40 percent less hearing loss than those on the placebo, according to her study. Published Jan. 2 in the Annals of Internal Medicine, it appeared after she had joined the staff at the Nestle Research Center in Lusanne, Switzerland. She conducted her research while at Wageningen University in the Netherlands.

The latest research on folate and cardiovascular health has come in with a neutral conclusion. A report last month in The Journal of the American Medical Association analyzed 12 randomized controlled trials and found that folic acid supplements provide "no significant benefit or harm" to those at risk of stroke or heart disease.

There is no dispute about the need for folate among women of reproductive age. Deficits among mothers were found to cause at least half of neural-tube birth defects such as spina bifida.

In 1998, the U.S. Food and Drug Administration began requiring manufacturers to fortify grain-based cereals, breads and pastas with folic acid before marketing them as enriched. Other nutrients in enriched flour include iron, thiamin, niacin, riboflavin and vitamin B6.

As folate levels increased, the number of neural tube defects dropped to 3,000 from about 4,000 a year in 1998.

"It's been a major public health victory," Mulinare said.

A multivitamin with folic acid is recommended for women in their reproductive years to ensure a healthy fetus. An adequate level is needed up to six weeks before conception, experts say.

But surveys show that only a third of young women take a multivitamin - and that half of all pregnancies are unexpected.

In response to the drop in women's folate levels, an advocacy group wants twice as much folate in enriched foods.

Jennifer Howse, president of the March of Dimes, said, "Our position is that it's appropriate to double the fortification amounts of folates now going into enriched grains."

The group, which fights birth defects, is preparing a petition to file with the FDA in the coming months. Higher folate levels wouldn't pose any risks, she said.

A spokesman for the FDA said it is premature for the agency to comment.

The FDA requires 140 micrograms of folic acid per 100 grams of grain. (A microgram is one-millionth of a gram, and there are about 28 grams in every ounce of bread flour.)

Costs would be minimal, experts say.

"Most people agree that we would not see any significant negative effects from increased fortification," said Marcia Scheideman, president of the Wheat Foods Council, which represents many bread and cereal producers.

But some urge caution.

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