Blog | Wednesday, December 19, 2012

QD: News Every Day--Junk food may cause colon polyps in patients already susceptible to them

Junk food diets were associated with more colorectal adenomas in patients with Lynch syndrome, who are already at a high risk of developing colorectal cancer due to mutations in mismatch repair genes and who develop colorectal adenomas at a younger age, a study found.

Researchers used a food frequency questionnaire to collect dietary information from 486 patients with Lynch syndrome in the Netherlands. Four dietary patterns were identified: ---prudent, consisting of fruits and vegetables, whole grains, nonfat or low-fat dairy, poultry, fish and tea with added sweets,
--meat, heavily loaded on meats and coffee and negatively loaded on whole grains, peanut butter, cakes and cookies, and vegetable products,
--snacks, consisting of fried foods and snacks, butter, peanut sauce, ketchup, sweets, and diet sodas, and
--cosmopolitan, consisting of vegetables, fishes, dressings and spreads, and wine.

Results appeared online Dec. 17 in Cancer.

During a median follow-up of 20 months, colorectal adenomas were detected in 58 persons. After adjusting for age and sex, patients in the highest tertile of the snack pattern was associated with an increased risk of colorectal adenomas (HR, 2.16; 95% CI, 1.03-4.49).

Those in the highest tertiles of the other three dietary patterns did not have as much of an association for colorectal adenomas as the lowest tertiles, (prudent pattern; HR, 0.73; 95% confidence interval [CI], 0.32-1.66) (meat pattern; HR, 1.70; 95% CI, 0.83-3.52) (cosmopolitan pattern; HR, 1.25; 95% CI, 0.61-2.55).

The findings suggest that certain dietary patterns influence the development of polyps in individuals with Lynch syndrome, said the lead author in a press release. "Unfortunately, this does not mean that eating a diet low in snack foods will prevent any polyps from developing, but it might mean that those Lynch syndrome patients who eat a lot of snack foods might have more polyps than if they ate less snack foods."

Lynch syndrome is believed to be responsible for 2% to 7% of the 160,000 new cases of colorectal cancer that are diagnosed annually, according to the U.S. Library of Medicine.