Legend has it that coffee’s potential was originally discovered by an Ethiopian goatherd by the name of Kaldi, who noticed that his flock became particularly active after eating the berries of a certain tree. Today, coffee is one of the most popular beverages in the world, prized both for its taste and its ability to improve focus and stave off fatigue. More recently, it has been associated with positive health benefits, including a reduction in the risk for certain cancers.
Now a new study published in the British Medical Journal (BMJ) Open has found that coffee can reduce prostate cancer risk as well.
Drinking coffee has previously been linked to a reduction in breast, liver and bowel cancer risk, according to a BMJ press release, so the fact that its physiological benefits extend to prostate cancer is not wholly surprising. Prostate cancer, the second most common cancer diagnosis and the sixth leading cause of cancer death in men, claims more than 31,000 lives each year.
By analyzing the results of 16 cohort studies published between April 1989 and July 2019, researchers at Shengjing Hospital of China Medical University determined that higher coffee intake was associated with lower prostate cancer risk in men of all ages.
Each daily cup of coffee drunk, they found, conferred a 1% reduction in prostate cancer risk. “[C]affeine may be the key component in coffee” responsible for this benefit, the researchers wrote, citing earlier research.
Seven of the studies were published in North America, seven in Europe and two in Japan. In total, they involved 1,081,586 male participants who drank between zero and nine cups of coffee a day; 57,732 of those participants were eventually diagnosed with prostate cancer.
The more daily cups the men drank, the lower their risk of developing prostate cancer. The benefits extended all the way up to an average of nine cups a day, which was statistically linked to a 9% reduction in prostate cancer risk. These results are “evidence of a linear inverse association between coffee consumption and prostate cancer risk,” the researchers wrote.
When those proportions were filtered by cancer severity, the researchers found that men with the highest coffee intake had a 7% reduced risk for localized prostate cancer, a 12% reduced risk for advanced prostate cancer and a 16% reduced risk for fatal prostate cancer.
One drawback of the new study, the researchers acknowledged, was that it drew on data from studies with different methodologies and metrics. But it makes scientific sense that coffee would reduce prostate cancer risk, they noted. The beverage is known to reduce inflammation, increase antioxidant load, speed up glucose metabolism and affect sex hormone levels—physiological phenomena that may influence the development and progression of prostate cancer.
Further research is necessary, the researchers say, but should independent investigation confirm their results, “men might be encouraged to increase their coffee consumption to potentially decrease the risk of prostate cancer.”
According to Johns Hopkins Medicine, a coffee habit is also linked with a lower risk of stroke, diabetes, heart failure, Parkinson’s disease and Alzheimer’s disease. For general health, however, nine cups a day may be excessive. The Food and Drug Administration (FDA) recommends limiting yourself to 400 milligrams of caffeine a day—the equivalent of about four or five cups of coffee. However, the FDA also says individual sensitivity to caffeine varies widely.
To learn more about how your diet can affect your advanced cancer risk, read “A Mediterranean Diet May Prevent Progression of Low-Grade Prostate Cancer.” And to read about a sports star’s previous battle with prostate cancer, read “NBA Legend Kareem Abdul-Jabbar Reveals Past Prostate Cancer Diagnosis.”