Soft drinks may increase cancer risk, while green tea is protective North Americans would do well to drink fewer soft drinks and a little more green tea – researchers say carbonated beverages may increase the risk for cancer of the esophagus, while green tea is protective.

Dr. Mohandas Mallath, head of the digestive diseases department at Tata Memorial Hospital in India, says the incidence of esophageal cancer has been rising in Western countries along with an increase in soft drink consumption.

He and his colleagues used data from the U.S. Department of Agriculture to look at dietary changes over the past 50 years and found that per capita consumption of carbonated soft drinks in the U.S. rose by more than 450 per cent. During roughly the same time period, the incidence of esophageal cancer shot up more than 570 per cent among white males and continues to increase.

In contrast, countries with a low consumption of soft drinks – such as Japan, China and India – have had little increase in the incidence of esophageal cancer.

Mallath says soft drinks trigger acid “reflux” from the stomach that damages the esophagus over time.

The damage can lead to Barrett’s esophagus, a change in the lining of the esophagus that can increase the risk of cancer.

Meanwhile, researchers at Harvard University in Boston say a chemical in green tea can block the growth of cancers associated with Barrett’s esophagus.

“Our results suggest that extracts in green tea may help to lower the prevalence of esophageal (cancer). I think the results are pretty exciting,” says Dr. Howard Chang, the lead investigator.

“Esophageal cancer is one of the fastest growing cancers in Western countries, and unfortunately our treatment options are pretty limited and long-term outcomes are very poor.”

The researchers studied the green tea chemical in cancer cells in the laboratory, but Chang says two cups per day of green tea may achieve similar effects, depending on the concentration of the tea.

(The Medical Posting – Men’s Health section, June 2004)