Folate tied to lower colon cancer risk
Sep 2, 2011, 1:14 p.m.
Those studies suggested that "in normal tissues, giving folate or folic acid can ensure DNA replicates and cells are grown properly," he explained. "But once cells are pre-cancerous, giving folate can increase the progression of these cancer cells."
In other words, it's possible that if someone already had cell changes that are precursors of colorectal cancer, too much folate could make the cancer grow faster.
The current findings, he told Reuters Health, are "reassuring" that fortifying grains with folate did not seem to lead to a spike in colorectal cancers. However, Kim added, "there's still a concern that those taking really high levels of folic acid (in supplements) may be detrimental."
Gibson agreed that the new report doesn't close the door on that possibility, especially because some cancers take many years to develop. More studies will have to look at the risk of colorectal cancer over longer periods of time, he said. But, so far "we don't see any evidence of increased risk," he added.
To be safe, Kim said that people who do have colon cancer should not take extra folate, and that others shouldn't see any need to overdo it.
"If people take 400 micrograms a day, I think that's going to be sufficient to meet your health benefits from folate," he said.
Based on the current study, "people don't need to change their current activities" with respect to folate, Gibson said. "Most people are getting what is considered the adequate amount."
SOURCE: http://bit.ly/rkRtC0 American Journal of Clinical Nutrition, online August 3, 2011.