'Digestible' carbohydrate may boost colorectal cancer risk
NEW YORK, Jun 27 (Reuters Health) - Previous studies have not agreed on whether or not eating lots of carbohydrates is a risk for colon cancer. In a new study, Canadian researchers set aside the fiber content of carbohydrates, which may reduce the risk, and examined the remainder, or "digestible" carbohydrate, namely sugars and starches. The result: their study showed that people consuming the highest amounts of digestible carbohydrates had a higher risk for developing colorectal cancer compared with those eating the lowest amounts.
Of particular interest was the finding that, when it comes to colorectal cancer risk, "digestible carbohydrates act differently in women than in men," Marilyn Borugian, research associate at the British Columbia Cancer Agency in Vancouver, told Reuters Health.
Borugian and colleagues at the University of British Columbia analyzed data on digestible carbohydrate consumption in about 490 Chinese immigrants with colorectal cancer and 1,100 healthy Chinese immigrants. All the study participants were between 40 and 80 years of age and living in North America.
The researchers took into account colorectal risk factors such as age, saturated fat and fiber intake, calcium consumption, body mass index (a calculated ratio of weight to height), physical activity, and family history to determine if there was an association between digestible carbohydrate consumption and colorectal cancer risk in the study group.
The investigators found that, at the highest levels of intake, digestible carbohydrate did appear to increase cancer risk, but gender played a role in the site of the cancer in the large intestine.
"In women, the higher risk for cancer was in the right colon," Borugian said. The right colon is the beginning of the loop-shaped large bowel. Subjects with the highest consumption of non-fiber carbohydrate had roughly a seven-fold increased risk compared to those with the lowest consumption.
But in men, the picture was different. Men with the highest consumption of digestible carbohydrates had a two-fold increased risk for rectal cancer--at the end of the large bowel--compared to those eating the lowest amounts of non-fiber carbohydrates.
Borugian believes that knowledge of these gender differences should be taken into account during colorectal cancer screening.
"Eating a lot of any one food type incurs risks of some sort," Borugian said. These findings support the adages, "everything in moderation," or, "eat less and eat veggies," she added.
The study results were presented at the recent Society for Epidemiologic Research meeting held in Seattle, Washington.