Coffee as Cancer Prevention? Men who drink coffee regularly are less likely to develop prostate cancer – this is suggested by a large meta-study. The more coffee, the lower the risk. Each additional cup daily is said to reduce the relative risk by almost one percent. The results should be viewed with caution, however, as the studies evaluated came to very different results.
coffee is not just one of the most popular drinks worldwide. Studies also suggest that the caffeinated drink has positive health effects in a number of ways: It could the heart and the vessels protect, the DNA keep fit and Diabetes prevent. Coffee has also been linked to a reduced risk of liver, colon and breast cancer.
This raises the question of whether coffee could also help prevent prostate cancer, the most common type of cancer in men in Germany. So far, however, there is little reliable knowledge about the influence of factors such as lifestyle, environment and diet on the risk of prostate cancer.
Previous studies evaluated
There have also been numerous studies on a possible connection between coffee consumption and prostate cancer, although some of them came to contradicting results. A team led by Xiaonan Chen from Shenyang Medical University in China has therefore now summarized and evaluated the data from 16 studies with a total of over a million participants. In the course of these studies, 57,732 participants developed prostate cancer.
To find out what role coffee drinking played in this, 15 of these studies compared the prostate cancer risk of participants with the highest and lowest levels of coffee consumption. 13 also determined how the cancer risk changed with each additional daily cup. Two to nine cups of coffee per day were considered heavy consumption, the participants with the lowest coffee consumption drank no or less than two cups a day.
Less cancer with high coffee consumption
The evaluation showed: “In our meta-analysis, a higher coffee consumption was significantly linked to a lower risk of prostate cancer in men,” reported Chen and his team. Specifically, the relative risk of high coffee drinkers was nine percent lower than that of the group that drank the least coffee. Each additional cup of coffee drunk a day reduced the relative risk by one percent.
However, the relative risk only provides information about the difference between the groups. Overall, doctors assume that older men have an absolute prostate cancer risk of around five percent. This value decreased to 4.81 percent for the heavy coffee drinkers. The practical effect is therefore rather small.
How high is the significance?
For their analysis, the researchers only included so-called cohort studies. These studies measured the participants’ coffee consumption at the beginning and during the course and then observed over several years who developed prostate cancer. Compared to studies that retrospectively compare sick people with non-sick people, cohort studies are considered more reliable because they are less distorted by the memories of those involved.
But the informative value of the present meta-study is also limited. The studies included in some cases produced contradicting results – some even came to the conclusion that high coffee consumption is more of a risk than a protective factor. What kind of coffee it was, how it was brewed and how the number of cups drunk was recorded and classified also varied from study to study. Other possible influencing factors may also not always have been fully recorded.
Biological explanations for the context
Still, there are plausible biological explanations for the assumption that coffee lowers the risk of prostate cancer, the researchers point out. Coffee improves glucose metabolism, has anti-inflammatory and antioxidant effects and influences sex hormone levels. All of these could affect the development, development, and progression of prostate cancer.
“Further studies are needed to investigate the underlying mechanisms and active compounds in coffee,” the researchers conclude. “If the link proves to be causal, men could be encouraged to increase their coffee consumption, possibly to reduce the risk of prostate cancer.” (British Medical Journal, 2021; doi: 10.1136 / bmjopen-2020-038902)