A study with almost 50,000 men over four years found that males with the highest intake of coffee had significantly lower risks of aggressive prostate cancer. The study is said to be the first study of its kind to look at both overall risk of prostate cancer and risk of localized, advanced and lethal disease.
"Coffee has effects on insulin and glucose metabolism as well as sex hormone levels, all of which play a role in prostate cancer. It was plausible that there may be an association between coffee and prostate cancer," said Kathryn Wilson, PhD, from Harvard Medical School and the Harvard School of Public Health.
The researchers presented their findings at the American Association for Cancer Research Frontiers in Cancer Prevention Research Conference. NutraIngredients has not seen the full data.
Benefits of the bean
The beverage, and its constituent ingredients, has come under increasing study with research linking it to reduced risk of diabetes, and improved liver health.
Coffee, one of the world's largest traded commodities produced in more than 60 countries and generating more than $70bn in retail sales a year, continues to spawn research and interest, and has been linked to reduced risks of certain diseases, especially of the liver and diabetes.
"Few studies have looked prospectively at this association, and none have looked at coffee and specific prostate cancer outcomes," explained Wilson. "We specifically looked at different types of prostate cancer, such as advanced vs. localized cancers or high-grade vs. low-grade cancers."
The Harvard researchers used data from the Health Professionals' Follow-Up Study to investigate the association between regular and decaffeinated coffee intake and prostate cancer. Over the course of 20 years, 4,975 cases of prostate cancer were diagnosed. Men with the highest intakes had a 60 per cent lower risk of advanced prostate cancer, said the researchers.
Wilson said that caffeine is actually not the key factor in this association, but the actual bioactive components are not known.
"Very few lifestyle factors have been consistently associated with prostate cancer risk, especially with risk of aggressive disease, so it would be very exciting if this association is confirmed in other studies," said Wilson. "Our results do suggest there is no reason to stop drinking coffee out of any concern about prostate cancer."
Too early to draw conclusions
Commenting independently on the research, Helen Rippon from UK charity, The Prostate Cancer Charity, said: “The research evidence so far on the relationship between caffeinated drinks and prostate cancer has been quite mixed, and has largely focused on the risk of developing the disease and the role that drinks like tea and coffee might have in cancer prevention.
“This large scale study looked instead at whether coffee drinking might influence the aggressiveness of prostate cancer in men who do develop the disease. This research does provide a clue that coffee drinking might reduce the likelihood of a man being diagnosed with a more advanced prostate cancer, although there is still more research to do to confirm this and to uncover which component of coffee could be responsible.
“We would not recommend that men cultivate a heavy coffee drinking habit on the back of this research, not least because a high caffeine intake can cause other health problems. However, men who already enjoy a regular cup of coffee should be reassured that they do not need to give this up for the sake of their prostate,” she said.
Over half a million men worldwide are diagnosed with prostate cancer every year, with over 200,000 deaths from the disease. The lowest incidence of the cancer is in Asia and the Far East, in particular India and China.