Data from a population-based study of newly diagnosed cases of
prostate cancer (n = 362) and age-matched controls (n = 685) conducted in Utah (United States) between 1983 and 1986 were used to determine if cigarette smoking, alcohol,
coffee,
tea,
caffeine, and
theobromine were associated with
prostate cancer risk. These factors were examined since their use differs in the Utah population, which is comprised predominantly of members of the Church of Jesus Christ of Latter-day Saints (LDS or Mormon), from most other populations. Pack-years of cigarettes smoked, alcohol intake, and consumption of alcohol,
coffee,
tea, and
caffeine were not associated with
prostate cancer risk. Compared with men with very low levels of
theobromine intake, older men consuming 11 to 20 and over 20 mg of
theobromine per day were at increased risk of
prostate cancer (odds ratio [OR] for all
tumors = 2.06, 95 percent confidence interval [CI] = 1.33-3.20, and OR = 1.47, CI = 0.99-2.19, respectively; OR for aggressive
tumors = 1.90, CI = 0.90-3.97, and OR = 1.74, CI = 0.91-3.32, respectively). We present
biological mechanisms for a possible association between
prostate cancer and
theobromine. This finding needs further exploration in studies with a wider range of
theobromine exposures and more men with aggressive
tumors.