Results of a new study from the University of Glasgow and published in Nutrition and Cancer have stated that men who drank more than seven cups of tea daily had a 50% greater risk of developing prostate cancer than did men who drank less than four cups of tea daily or no tea at all.
- Before you put down your mug of tea (green tea, we hope), consider the following limitations regarding the study. The study looked at the use of black tea, while numerous studies have shown that green tea helps prevent prostate cancer or has a role in prostate cancer prevention
- The study’s lead investigator, Dr. Kashif Shafique, admitted “We don’t know whether tea itself is a risk factor or if tea drinkers are generally healthier and live to an older age when prostate cancer is more common anyway.” The study did not take into consideration the men’s family history or any other dietary habits except the men’s use of coffee, tea, and alcohol.
- The study in question evaluated the tea drinking habits of 6,016 men aged 21 to 75 over a 37-year period. Slightly less than 25% of the men in the study consumed seven or more cups of tea per day. Among this group, 6.4% developed prostate cancer during the follow-up period.
As an aside, results of a meta-analysis study published last year in Nutrition and Cancer (Zheng et al) also were concerned with tea consumption and prostate cancer risk. That study looked at both black tea and green tea and the reviewers noted that “this meta-analysis supported that green tea but not black tea may have a protective effect on PCa [prostate cancer], especially in Asian populations.”
So what does this latest study from the University of Glasgow mean? The researchers concluded that “the association between tea intake and prostate cancer should be investigated in prospective epidemiological studies in relation to different compositions of tea.”
For men who drink tea, it could be a call to switch to green tea since the prostate cancer benefits of green tea have been researched, or to reduce their intake of black tea if they are drinking seven or more cups per day.
In the words of Dr. Kate Holmes, head of research at the Prostate Cancer Charity, in light of the study’s limitations, “We would therefore not wish any man to be concerned that drinking a moderate amount of tea as part of a healthy diet will put them at an increased risk of developing prostate cancer.”
Read more in our Prostate Cancer Health Center.
Shafique K et al. Tea consumption and the risk of overall and grade specific prostate cancer: a large prospective cohort study of Scottish men. Nutrition and Cancer 2012 Aug; 64(6): 790-97