- Coffee can promote liver health, according to a new analysis of decades of existing data.
- In addition to affirming proposed connections between coffee and a healthier liver, the new review identifies the molecular pathways through which such connections may occur.
- As a result of the compounds it contains, coffee can support liver health in at least five different and significant ways.
- The effects of coffee are dose-dependent, says the review, and the ability to tolerate its consumption is highly individualized.
An expansive new review published in Biochemical Pharmacology. adds to existing evidence that drinking coffee regularly can help protect and even restore the health of one’s liver by inhibiting scarring and inflammation.
In addition to affirming previously noted associations between coffee and liver health, the review identifies potential molecular pathways that explain these beneficial relationships.
The review is a new compilation and analysis of decades worth of epidemiological, experimental, and clinical data documenting coffee’s liver-health potential.
It has long been suggested that coffee’s robust blend of bioactive compounds have the ability to reduce the risk of liver disease. Its consumption is believed to slow liver disease’s progression to fibrosis, cirrhosis, and hepatocellular carcinoma, thanks to coffee’s robust mix of bioactive compounds.
The review does more than spotlight associations between coffee-drinking and liver health. It also endeavors to explain chemically how these compounds help maintain the liver, describing a wide range of antioxidant, anti-inflammatory, and antifibrotic effects from coffee drinking.
Coffee also appears to help balance the gut microbiome, and even help moderate epigenetic influences that can affect liver health.
Coffee is a complex brew of bioactive compounds, in addition to its well-known ingredient caffeine, explained Michelle Routhenstein, MS, RD, CDCES, CDN, a preventive cardiology dietitian at EntirelyNourished, who was not involved in the review.
“Coffee contains specific compounds like chlorogenic acid and polyphenols that have antioxidant, anti-inflammatory and liver-modulating effects that may help promote liver health,” Routhenstein said.
Coffee’s antioxidant properties may be especially important, since, as the dietitian pointed out, “oxidative stress can negatively impact the cells on the liver, promoting inflammation and insulin resistance.”
Oxidative stress is a major driver of liver damage.
The review’s analysis of such a large collection of data confirmed previous indications of associations between coffee consumption and a reduction in the incidence of several prominent liver diseases.
For people with chronic hepatitis C, for example, coffee drinking was again seen to be inversely associated with liver damage severity.
People with hepatitis C who drank coffee daily experienced significantly lower rates of progression to fibrosis and cirrhosis. Drinkers of 2 cups a day also were less likely to develop hepatocellular carcinoma, which can often occur with hepatitis C.
Correlations between coffee and reduced severity for two major causes of liver-related morbidity and mortality were also reported in the review.
Alcoholic liver disease is the result of excessive alcohol consumption. Its damage to the liver is associated with the presence of liver enzymes AST, GGT, and ALT. People who regularly drink coffee have lower levels of these enzymes.
Metabolic dysfunction-associated steatotic liver disease, or MASLD, is the most common chronic liver disease globally. The review reported that people who drank coffee regularly were 29% less likely to develop MASLD than nondrinkers.
Importantly, the authors of the review traced the chemical mechanisms behind coffee’s purported beneficial properties by aligning them with likely specific molecular targets within the liver.
They investigated five areas:
- antioxidant support for the liver
- anti-inflammatory support for the liver
- antifibrotic support for the liver
- metabolism support
- support for gut microbiome balance.
For the first four areas, the authors pinpointed specific molecules that had been shown to be positively influenced by coffee in the existing data. In the fifth, they identified a variety of gut microbiome-balancing bacteria that coffee helps promote.
“The amount of caffeine that is generally safe is about 400 milligrams (mg) [about 3–4 cups] per day but this amount can vary based on individual tolerance,” said Routhenstein.
The review notes that for people with caffeine hypersensitivity, existing cardiovascular disease, or anxiety disorders, adverse effects may occur even with small amounts of coffee.
“Many people,” said Routhenstein, “may experience heart palpitations, anxiety, insomnia, acid reflux and GI distress at lower amounts, so the quantity will need to be adjusted for the individual.”
The review points out as well that coffee’s beneficial effects are dose-dependent.
Consuming more than 5 cups of coffee daily, for example, can increase serum LDL (“bad”) cholesterol levels and potentially contribute to dyslipidemia.
Coffee may also be beneficial for the heart, noted Routhenstein:
“Since liver health is connected to heart health, it is no surprise that several studies show that moderate consumption of black coffee has also been shown to potentially be beneficial for the heart, if tolerated well.”
“The amount of caffeinated coffee consumption should be individualized for optimal outcomes, and caution should be taken in those with pre-existing heart conditions and/or on certain medications like beta blockers and blood thinners,” she added.
The authors note that coffee may have a role to play as a simple and viable dietary intervention for people with liver disease, especially when considered in the context of other modifiable lifestyle factors.
Still, the review’s identification of coffee-relevant molecular pathways, its authors assert, could open new avenues of research for the types of randomized clinical trials. They also point out that further research will be required to prize out further details for clinical purposes.
