A Coffee A Day Keeps The Doctor Away?

Linking Coffee To The Liver

In one review, about 355,000 adults in the UK Biobank were followed for roughly 13 years. The study tracked how much coffee people said they drank over this period. Data were also gathered on who went on to develop cirrhosis, liver cancer or die from liver disease. Scan data and blood tests for a subset of participants were collected so they could see who got sick and what the liver looked like in regular coffee drinkers versus non-drinkers.

Coffee drinkers showed lower levels of liver fat, iron and fibroinflammation, imaging markers associated with a healthier liver. Blood protein analysis told a similar story. Coffee drinkers had higher levels of proteins tied to healthy liver synthesis and immune regulation alongside lower levels of proteins linked to scarring.

People who drank five or more cups of coffee a day had a 32% lower risk of cirrhosis, a 47% lower risk of liver cancer and a 42% lower risk of dying from liver disease compared with people who did not drink coffee at all. Importantly, the benefits did not require heavy consumption. Improvements were found even among participants who drank one or two cups a day. This was found for both caffeinated and decaffeinated coffee. Therefore, caffeine alone does not explain the benefit. Coffee contains hundreds of bioactive compounds that may influence inflammation and fibrosis independently of caffeine content.

As the study is observational, it shows a strong link but cannot prove that coffee itself is the cause. It can only show that the link exists. While the liver findings capture attention on their own, they arrive alongside a parallel body of evidence on cardiovascular health.

Hooking Coffee to the Heart

An American Heart Association review concluded that up to 400 milligrams of caffeine daily is generally safe for most adults. That equates to roughly three to five 8-ounce cups of black coffee. This amount is considered a safe range. It is not associated with higher rates of heart attack or stroke.

Across the studies examined, it was also found that people who drink coffee regularly tend to have slightly lower risks of coronary heart disease, heart failure, stroke and Type 2 diabetes than people who avoid it. The review also tackled a long-running concern: heart rhythm. Moderate coffee intake does not appear to raise the risk of atrial fibrillation. In some analyses, it may even be linked to fewer recurrences. Controlled trials, on the other hand, do show that caffeinated coffee can increase harmless extra beats in the heart.