Contrary to expectations, diets high in the nutrient choline were associated with an increased risk of some colorectal polyps, which can, but do not always, lead to colorectal cancer, according to a study published online in the August 7 Journal of the National Cancer Institute.
Major food sources of choline include red meat, eggs, poultry, and dairy products. Choline is involved in a biochemical process known as one-carbon metabolism. Studies have shown that people with increased intake of other nutrients required for one-carbon metabolism, such as folate, are at a decreased risk for colorectal polyps. This is the first study to examine the association between choline and colorectal polyps.
Eunyoung Cho, Sc.D., of Brigham and Women's Hospital in Boston and colleagues sent food-frequency questionnaires to women enrolled in the Nurses, Health Study every two to four years from 1984 to 2002. They then estimated the choline content in their diets.
The researchers had hypothesized that choline intake would decrease the risk of colorectal polyps like folate does. But the results suggest the opposite, greater amounts of choline in the diet were associated with an elevated risk of colorectal polyps.