Drinking coffee protects against prostate cancer, research suggests

18 Mar 2019 --- Certain coffee compounds may inhibit the growth of prostate cancer. This is according to a new pilot study, carried out on drug-resistant cancer cells in cell culture and in a mouse model. Published in the journal The Prostate, the study was presented at the European Association of Urology congress in Barcelona, Spain. The authors note that further research is warranted and clinical testing in humans, to determine the effects the compounds may have on health.

Japanese researchers studied the effects of two compounds found in coffee, kahweol acetate and cafestol, on prostate cancer cells and in animals. They found that the compounds were able to hinder growth in cells which are resistant to common anti-cancer drugs such as Cabazitaxel.

Initially, the researchers examined six compounds found in coffee, on the proliferation of human prostate cancer cells in vitro. They found that cells treated with kahweol acetate and cafestol grew more slowly than controls. Then, the researchers tested the compounds on prostate cancer cells which had been transplanted to 16 mice. Four mice were controls, four were treated with kahweol acetate, four with cafestol, with the remaining mice being treated with a combination of kahweol acetate and cafestol.

“We found that kahweol acetate and cafestol inhibited the growth of the cancer cells in mice, but the combination seemed to work synergistically, leading to a significantly slower tumor growth compared to untreated mice,” says lead author Dr. Hiroaki Iwamoto from the Department of Integrative Cancer Therapy and Urology at Kanazawa University.

“After 11 days, the untreated tumors had grown by around 3.5 times the original volume, whereas the tumors in the mice treated with both compounds had grown by around just over 1.5 times the original size,” he notes.

Iwamoto stresses that it is important to keep these findings in perspective as this was a pilot study. “This work shows that the use of these compounds is scientifically feasible, but needs further investigation. It does not mean that the findings can yet be applied to humans. We also found the growth reduction in transplanted tumor cells, rather than in native tumor cells,” he notes.

“It does show, however, that these compounds appear to have an effect on drug-resistant cells in the right circumstances and that they too need further investigation. We are currently considering how we might test these findings in a larger sample, and then in humans.”

The two compounds identified are naturally found in Arabica coffee. The coffee making process was found to influence whether the compounds remained in coffee after brewing (as with espresso) or whether they were stripped (as when filtered).

“These are promising findings, but they should not make people change their coffee consumption. Coffee can have both positive and negative effects, such as increasing hypertension,” says Professor Atsushi Mizokami of the Department of Integrative Cancer Therapy and Urology at Kanazawa University.

“So we need to find out more about the mechanisms behind these findings before we can think about clinical applications. However, if we can confirm these results, we may have candidates to treat drug-resistant prostate cancer,” he adds.

Research on coffee’s potential health benefits
Previous research has found that light roast coffee holds anti-cancerous properties that darker roast coffee does not. The study, published in The Journal of Food Science, compared coffee roasted at five different levels, against the growth inhibitory activity of cancer cells that are associated with oral and colon cancers. Another study discovered that certain compounds found in coffee called phenylindanes may hinder two protein fragments responsible for Alzheimer’s and Parkinson’s from clumping, therefore potentially aiding in the prevention of these diseases.

Adding to the benefits of the world’s favorite beverage, research has shown that coffee consumption can reduce the risk of death by up to 17 percent. The report is the outcome of a roundtable discussion hosted by The Institute for Scientific Information on Coffee (ISIC). The roundtable report also considered the implications for healthcare practitioners.

Adding to the above, consuming coffee was also associated with lower mortality rates and can be part of a healthy diet, according to a study published in JAMA Internal Medicine. Researchers found that those who drink six or seven cups of coffee per day were 16 percent less likely to die from a fatal disease than those drinking no coffee.