Coffee is widely known to increase wakefulness and boost concentration and focus, but a new report reveals that regular coffee intake could also reduce liver cancer risk caused by daily alcohol consumption.
The research, conducted by the London, UK-based World Cancer Research Fund International, looked at a variety of diet- and lifestyle-related factors that impact the risk of liver cancer. After reviewing published literature on the topic, the researchers determined that drinking three alcoholic drinks a day can be enough to cause liver cancer.
“Around three or more drinks per day can be enough to cause liver cancer. Until now we were uncertain about the amount of alcohol likely to lead to liver cancer. But the research reviewed in this report is strong enough, for the first time, to be more specific about this,” says Dr. Amanda McLean, Director of World Cancer Research Fund UK.
The findings were published in the Continuous Update Project (CUP) 2015 report on “diet, nutrition, physical activity and liver cancer.” They are based on an analysis of 34 studies that included 8.2 million people, of whom more than 24,500 had liver cancer.
The meta-analysis also revealed strong evidence that drinking coffee can reduce the risk of liver cancer. This discovery follows research the World Cancer Research Fund published in 2013 showing that coffee reduced the risk of womb cancer.
“The new findings around alcohol, obesity and coffee are particularly interesting,” says Dr. Kate Allen, Executive Director of Science and Public Affairs at World Cancer Research Fund International. “The evidence about the relationship between diet, nutrition, physical activity and cancer is becoming well established. We hope that these new findings will inform the debate about possible public health implications and policy responses.”
‘Significantly decreased risk of liver cancer’ per one cup of coffee per day
Mechanisms that support a protective effect of coffee on liver cancer relate largely to studies in animals, although some human studies contribute to the evidence.
Both coffee and coffee extracts have also been shown to reduce the expression of genes involved in inflammation, and the effects appear to be most pronounced in the liver. There is evidence from small intervention studies that coffee consumption reduces DNA damage in blood cells and prevents ex vivo-induced DNA damage in healthy volunteers.
In the review, researchers determined that the risk of developing liver cancer might be reduced by approximately 14% by consuming one cup of coffee per day.
“The evidence for coffee was generally consistent, and the dose-response meta-analysis showed a significantly decreased risk of liver cancer per one cup per day,” the report says. This evidence is consistent with findings from three published meta-analyses, the report says, but when stratified by sex, the association was significant for men but not for women.
The CUP panel concluded that a “higher consumption of coffee probably protects against liver cancer.”
The panel does note, however, that there is no evidence regarding specific components of coffee that may account for the decreased risk. There is also uncertainty about the various variables that may affect the association between coffee consumption and reduced liver cancer risk, such as caffeine, sugar and milk. Due to the effect of coffee on other medical conditions, recommendations for coffee consumption cannot yet be made.