Some previous studies have suggested that coffee and tea may lower the risk of cancer, but others show that they could increase the risk. Tea, for instance, contains antioxidants that in theory help prevent cancer but also has polyamines which in theory promote cancer. Sugar-sweetened soft drinks are associated with weight gain, obesity and other conditions that are potential risk factors for colon cancer.
For this study, Xuehong Zhang and colleagues at the Harvard School of Public Health analysed data from 13 studies conducted in North America and Europe. Among 731,441 study participants, there were 5,604 who developed colon cancer. Those who drank large amounts of coffee, more than six 8oz cups a day, were no more likely to develop the disease than those who drank less.