Coffee and Colas Won't Increase Colon Cancer Risk

Coffee and cola - good. Tea - bad.

Some good news about those much-maligned sugar-sweetened beverages: researchers say they won't make you more likely to develop colon cancer.
Neither will coffee, according to Xuehong Zhang, MD, ScD, of Harvard, and colleagues, reporting in the Journal of the National Cancer Institute. In a pooled analysis, they found that neither beverage increases the risk of colon cancer.

But the same does not hold true for tea, the researchers said. In fact, tea was associated with a 28% increased risk of the disease.

Zhang cautioned, however, that the small population of high-volume tea drinkers surveyed may have undermined the statistical power of the relationship.

"The finding of an increased risk of colon cancer with higher tea consumption ... was unexpected, and the results may be due to chance, because only 3% of our study population consumed that much tea," Zhang said in an e-mail to MedPage Today.

"More research on how tea consumption may affect tumor progression and metastasis is warranted," he added, as well as more research on "whether tea consumption affects colon cancer risk in populations with a wider range of tea intake, and on whether associations differ by the type of tea consumed or preparation method."

Some research has shown that polyphenols in coffee and tea protect against the formation of colon tumors, possibly through their antioxidant properties.

On the other hand, sodas and other sugar-sweetened beverages have been positively associated with weight gain, obesity, insulin resistance, and type 2 diabetes -- all of which are risk factors for colon cancer.

Individual studies of these relationships lacked clear conclusions. So to clarify the issue, the researchers conducted a pooled analysis of 13 prospective cohort studies from North America and Europe.

A total of 731,441 patients were followed for six to 20 years, during which time there were 5,604 incident cases of colon cancer.

The researchers found no risks of colon cancer with coffee consumption of up to six 8-oz cups per day, nor with soda intake up to 18 oz per day.

There was, however, a slightly increased risk of the disease with tea consumption, up to about four 8-oz cups per day (RR 1.28, 95% CI 1.02 to 1.61, P=0.01).

Still think they have any idea what they are talking about?