Marie Caudill conducted a controlled feeding study to ensure that recommended dietary allowance was adequate for women with an inherited gene that increases folate requirements.

Eat your greens. It's an edict parents have repeated like a broken record to children for generations.

It is in green leafy vegetables such as spinach and turnip greens-along with asparagus, strawberries, legumes, nuts and orange juice-that natural food folate is found, while enriched cereal-grains such as breads, pasta and rice provide man-made folic acid.

Folate is a water-soluble B vitamin necessary for the production and maintenance of new cells. It is especially important during periods of rapid cell division and growth such as infancy and pregnancy. Studies have shown that folate reduces birth defects and may decrease the risk of heart disease and certain cancers.

Cal Poly Pomona's Marie Caudill, assistant professor of human nutrition & food science, recently conducted a controlled feeding study where she made sure that the current recommended dietary allowance (RDA) was adequate for a group of women who have inherited a gene that increases folate requirements.

In 1998, the Institute of Medicine (IOM) approved RDA of 400 micrograms folate, which was devised to meet the needs of approximately 98 percent of the adult population. But Caudill questioned whether those recommendations were too low, particularly considering 10 to 12 percent of the general U.S. population and 20 percent of Mexican Americans carry a common genetic mutation that causes their folate levels to fall below average.

"My original hypothesis was that persons with the mutation would have higher folate requirements and that the current RDA may not be sufficient to meet the needs of women with the mutation," says Caudill.
During her three-year study, Caudill and a team of graduate and undergraduate students examined the effect of this common mutation on folate requirements and assessed whether the current folate RDA was adequate. The National Institutes of Health and the Agricultural Research Initiative funded the $500,000 study.

The study included providing 43 women-both with and without the mutation-three meals and a snack every day for 14 weeks. Participants were paid $1,400 each.

"They consumed breakfast and dinner in a metabolic kitchen and then we gave them their lunch and snacks to go. They had to come in on the weekends too, and could not consume any food outside the study," says Caudill. "It took a lot of dedication from the participants."

Sarah Moussavi, assistant to the dean at the College of the Extended University, says participating in the study was a "huge sacrifice," but that she was committed.

"It was really difficult not being able to eat with my family," she says. "But I learned that folate is a substance that is very necessary to have in your diet and that Hispanic women are at risk of not getting enough of it."
Upon completion of the study, Caudill's research supported a portion of her hypothesis. Data suggested it takes higher amounts of folate consumption for women with the genetic mutation to achieve the same folate status as women without the mutation.

But Caudill was surprised to find the study also demonstrated that the current RDA is adequate in achieving normal folate status for women with and without the genetic mutation.

"The good news for women is that those living in the United States don't have to worry about this particular genetic mutation affecting their folate status," she says. "However, for women living in countries that don't fortify the food supply with folic acid, such as Mexico, it is likely that those with the mutation are not consuming enough folate to overcome the genetic deficiency."

Caudill has expanded her study and is now examining the effect of ethnicity on folate requirements. The IOM will re-examine folate requirements in 2008, and Caudill hopes to include her data from various studies that either challenges or supports the current folate RDA. Ultimately, her findings could affect the amount of folate consumption throughout the United Sates.