Drinking coffee may offer substantial protection against severe liver disease, according to a large-scale study published in the journal Clinical Gastroenterology and Hepatology. The research, which analyzed data from 354,957 participants in the UK Biobank, indicates that regular coffee consumption is associated with a reduced risk of cirrhosis, liver cancer, and death from liver-related causes.
Participants who had no pre-existing liver conditions were monitored for an average of 13 years. The findings revealed that individuals who consumed one to two cups of coffee daily had a 20% lower risk of developing cirrhosis and a 31% lower risk of liver-related mortality compared to those who did not drink coffee. These protective effects were more pronounced in heavier coffee drinkers.
Those who drank five or more cups of coffee per day showed a 32% reduction in cirrhosis risk, a 42% lower risk of liver-related death, and a 47% lower risk of developing hepatocellular carcinoma, the most common type of primary liver cancer.
Researchers explored the biological mechanisms behind these associations through additional analyses of imaging data from nearly 29,000 participants and blood samples from approximately 50,000 individuals. The results showed that heavy coffee drinkers tended to have lower levels of liver fat and liver iron. They also had lower odds of developing fibroinflammation, a condition involving scarring and inflammation that can lead to permanent liver damage.
Blood sample analysis linked coffee consumption to decreased levels of proteins associated with inflammation and tissue scarring, while showing higher levels of proteins crucial for healthy liver function. Notably, the study found that both caffeinated and decaffeinated coffee provided similar liver-protective benefits, suggesting that compounds other than caffeine are responsible.
While the benefits were observed regardless of whether sweeteners were added, the researchers noted that the addition of sugar or artificial sweeteners appeared to slightly diminish these positive effects, particularly concerning markers of liver inflammation.
The study authors emphasized that while coffee consumption appears to be a beneficial dietary habit for liver health, it should complement, not replace, established preventative health practices. The study relied on self-reported dietary habits, which could be subject to changes over time, and as an observational study, it establishes correlation rather than proving a direct cause-and-effect relationship.