"They wanted to know if taking folic acid supplements would reduce a person's risk of developing colon cancer, colorectal cancer." says The Early Show's medical correspondent Dr. Emily Senay. "There were studies that suggested people who had low levels of folic acid might be more likely to get colon cancer. …And as we've learned over and over again, we have to test these things in rigorous clinical trials. That's what they did."
"So they took a group of 1,000 people. All these people had risk to develop colon cancer. They all had polyps in their colon. Half the group they gave about a milligram of folic acid to, the other half the group they gave a dummy pill. Then they did colonoscopies on them repeatedly over a number of years, looked to see what they found at the end of the study," Senay explains.
What they found was unexpected.
"Not only did folic acid not prevent the progression of the polyps in these people, but actually, by the end of the study, those people who had taken the folic acid had slightly more polyps. So this was really a big surprise," Senay explains. "And this really points out why studying these things in rigorous trials is so important so you get the best information."
Asked what the relationship between taking folic acid and developing more polyps might be, Senay says, "Right now it's just a theory. What they think is if you have folic acid before you develop cells that are sort of cancerous it might prevent them. But once you develop those cancerous cells, the folic acid might actually feed the cancer so it's a matter of timing. They don't know that for sure. That's the theory, the working theory at the moment."
One important note is that this study does not suggest that women who are pregnant should stop taking folic acid.
"These are two issues. Women who might become pregnant need to have folic acid in their diets and a supplement about 400 micrograms per day. The reason for that is study after study after study shows that it reduces the risk of preventing neural tube defects like Spina Bifida," Senay says. "So women in that age group must continue to take the folic acid. However, people over 60 need now to think carefully about how much folic acid they're getting in their diet and talk to their doctors, looking at the total amount that they're taking."
A high percentage of people in that age group, over 60, have these polyps.
"The people who tend to take these supplements tend to be people who are eating relatively healthfully anyway. They supplement many foods with folic acid.
So you want to look at your total intake and make sure you're not overdoing it," Senay explains. "The exact amount, not clear yet. Hopefully more studies will be done. If you're at risk for colorectal cancer, talk to your doctor."