Tea: Not So Hot for Cancer Prevention

Tea drinking is now a fairly well established as a negative risk factor for cardiovascular disease (CVD). People who drink more tea are at lower risk of developing CVD. In animals the consumption of tea and phytochemicals extracted from tea are associated with a reduced risk of cancer. However, in people the association between tea consumption remains mixed with some studies showing modest reductions but many other showing no significant reduction in the risk of various cancers. However, there is data linking tea drinking with an increased risk of throat and esophageal cancer.

Recently more Americans are consuming tea due in part to data suggesting it is a healthy beverage. A recent large study done in northern Iran where heavy tea drinking is the norm adds to the growing concern that tea drinking may be an important risk factor for esophageal cancer, but only if consumed hot or very hot. In this case control study researchers closely examined the temperature at which tea was usually consumed in those who developed esophageal cancer and a control group. About 39% of people customarily drank “warm” tea at less than 60 degrees centigrade. Another 39% consumed what was deemed “hot” tea at 60-64 degrees and a final 22% consumed “very hot” tea (65 degrees centigrade or more). Those who drank “very hot” tea had an over 8 times higher risk of esophageal cancer as those who consumed cooler tea. Those that drank it “hot” also had over double the risk of esophageal cancer.1The people living in northern Iran rarely smoke or drink alcohol and few are obese and most habitually consumed more than a liter of tea daily making the consumption of hot tea perhaps the major risk factor for developing esophageal cancer. The researchers found no overall association between tea drinking and esophageal cancer. It was only how hot people typically consumed their tea that made a connection. Certainly this data should not discourage anyone from drinking tea. However, it adds to growing evidence linking the consumption of very hot beverages to an increased risk of throat cancer. By James J. Kenney, PhD, RD, FACN 1. BMJ 2009;338:b929