Red Meat, Dairy Nutrient May Raise Colon Cancer Risk
Choline linked to increased polyp growth in women, study found
TUESDAY, Aug. 7, 2007 (HealthDay News) -- New research suggests that a nutrient in red meat, poultry and dairy products may contribute to the development of intestinal polyps, which can lead to colon cancer.
The study, which involved women only, was preliminary, and no one is yet suggesting a change in diet as a result.
However, the research into the nutrient, called choline, could ultimately lead to new dietary recommendations, said Eunyoung Cho, an epidemiologist at Brigham and Women's Hospital in Boston.
"There may be some impact," Cho said. "But this is one study, and it's hard to make any conclusion based on this study."
The role played by choline, a nutrient required by the body, has been unclear. Some researchers had thought it might provide protection against colon cancer, which kills an estimated 52,000 people in the United States each year, according to the American Cancer Society. The disease is the second biggest cancer killer in the United States after lung cancer.
In the new study, Cho and colleagues looked at nurses enrolled in a large study. They found more than 39,000 women who were free of colon cancer and then underwent at least one endoscopic examination between 1984 and 2002. Polyps -- benign growths that can lead to colon cancer -- were found in more than 2,400 of the women.
Women who ate the most choline in their food were 1.45 times more likely to have polyps, the team reported in the Aug. 7 online issue of the Journal of the National Cancer Institute.
Having more polyps doesn't necessarily mean more cancer, and future research will explore whether those who ate the most choline actually developed tumors, Cho said. Studies also need to look into the impact of choline on men.
Why might choline contribute to polyps, and possibly colon cancer, in the first place? The nutrient is a major component of the membranes of cells, Cho said, "and the tumor cell may need choline."
Currently, health officials recommend that people prevent colon cancer by eating a lot of fiber along with fruits and vegetables. Red meat, meanwhile, is thought to increase risk.
That dietary advice isn't likely to change even if choline turns out to be a possible villain, said Regina Ziegler, a senior investigator with the National Cancer Institute, who co-wrote a commentary accompanying the new study. "What they're finding is consistent" with the recommendations, she said.
As for now, "people shouldn't run out and start either taking more choline or less choline," she said.
There's more on colon cancer at the American Cancer Society.