Special Reports

High Doses Of Folic Acid May Lead To Colon Cancer

Many Pregnant Women Take Folic Acid Supplements To Guard Against Birth Defects

CHICAGO (CBS) ― Folic acid is in many of the foods we eat every day. It can prevent birth defects, but now research is linking it to an increase in colon cancer.

CBS 2 Medical Editor Mary Ann Childers reports some experts fear some women are getting to much of a good thing.

Julie Newell was diagnosed with stage 4 colon cancer in September. It had spread to her liver. She has two children, ages 2 years and 7 months. Newell has no known risk factors or family history, and is just 29 years old.

"All the young women who I've met or spoken to or heard about or have been about who have colon cancer in their 20s all recently had children," Newell said.

Newell took pre-natal vitamins containing folic acid for almost three straight years, to prevent the kind of birth defect 33-year-old Carolee Laird was born with.

It's spina bifida, and it causes life-long disability, including paralysis. Laird has had 30 surgeries, and faces challenges every day as she struggles to work and live independently.

"I know there are going to be times when it's going to be rough, but you just have to keep going with it," Laird said.

While exact cause is not known taking folic acid can cut the risk of spina bifida and other birth defects by 70 percent. Since the mid 1990s, the U.S. and Canada have been adding it to breads, cereals and grain-based products .

"After food fortification the rates of spina bifida dropped 31percent," said Rebecca May of the Spina Bifida Association.

The Food and Drug Administration says the amount of folic acid consumed in food is safe, even if people take an additional supplement. But a recent study to see if folic acid could prevent colorectal cancer unexpectedly found just the opposite.

A second study found that colon cancer cases in the U.S. and Canada -- which had been going down -- started going up at exactly the time food fortification started.

"We may have too much of a good thing. By trying to prevent one type of disease, we may have increased another type of disease," said Boris Pasche, M.D., Ph.D., Director of Cancer Genetics at Northwestern University.

Dr. Pasche, who's researching what triggers colon and breast cancers, says the coincidence is disturbing. Now that we're getting so much folic acid in food -- unless you're pregnant -- he believes people should approach additional supplements with caution.

"I would say right now there is no strong support in taking additional folic acid in view of these two studies," he said.

Dr. Pasche says we need more research on folic acid and cancer "because we may not know what we are doing exactly. We may be playing with fire."

Newell does not know what caused her illness, but finds the latest research on folic acid very troubling.

"I hope that women don't have to choose that they want to have a healthy baby, or do they want to have colon cancer?" she said. "But at the same time, I probably wouldn't change what I did for my kids."

This issue could spark a huge debate, especially because other, previous studies have linked folic acid to a lower incidence of some cancers. There is also no real agreement on how much folic acid is too much.

The March of Dimes says it would like to see the levels of folic acid added to foods doubled.

The American Cancer Society doesn't have a position yet on these two studies.

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