Drinking over four cups of coffee per day is linked to a reduced risk of prostate cancer recurrence and progression, says new study.
Corresponding author Janet L. Stanford, Ph.D., co-director of the Program in Prostate Cancer Research in the Fred Hutch Public Health Sciences Division, conducted the study to find if the bioactive compounds in coffee and tea may prevent prostate cancer recurrence and delay progression of the disease.
Stanford and colleagues found that men who drank four or more cups of coffee per day experienced a 59 percent reduced risk of prostate cancer recurrence and/or progression as compared to those who drank only one or fewer cups per week.
The authors wrote that it's important to note, however, that few patients in our cohort were regular tea drinkers and the highest category of tea consumption was one or more cups per day.
They further said that the association should be investigated in future studies that have access to larger populations with higher levels of tea consumption.
The population-based study involved 1,001 prostate cancer survivors, aged 35-74 years old at the time of diagnosis between 2002-2005, who were residents of King County, Wash.
Participants answered questions regarding their diet and beverage consumption two years prior to prostate cancer diagnosis using a validated food frequency questionnaire, and were interviewed about demographic and lifestyle information, family history of cancer, medication use and prostate cancer screening history.
The researchers followed up with patients more than five years after diagnosis to ascertain whether the prostate cancer had recurred and/or progressed.
Those who were still living, willing to be contacted and had been diagnosed with non-metastatic cancer were included in the follow-up effort.
Of the original 1,001 patients in the cohort, 630 answered questions regarding coffee intake, fit the follow-up criteria and were included in the final analysis.
Of those, 61 percent of the men consumed at least one cup of coffee per day and 12 percent consumed the highest amount: four or more cups per day.
The study also evaluated daily coffee consumption in relation to prostate cancer-specific death in 894 patients using data from the initial food frequency questionnaire.
After the median follow-up period of eight-and-a-half years, 125 of the men had died, including 38 specifically from prostate cancer. Daily coffee consumption was not associated with prostate cancer-specific mortality or other-cause mortality, but with few deaths these analyses were limited.
The study has been published online in Cancer Causes and Control.