Is Coffee Poison? | Cliff Harvey on Patreon

Coffee might be protective against diabetes.

Systematic reviews suggest a dose-dependent correlation between coffee intake and reduced rates of diabetes with the greatest effects seen in those consuming the highest amounts of coffee (greater than six cups per day). (1–3) For every additional cup consumed, there is an approximately 7% reduction in diabetes risk and benefits are also seen from tea and decaffeinated coffee. (4)

Be more cautious if you have a familial history of heart disease or other risk factors.

Coffee does increase blood pressure (BP) acutely (although these studies use high amounts in the range of 200–300 mg, approximately 2–3 cups of coffee) and this has led clinicians to urge caution with coffee intake due to a perceived risk of cardiovascular disease (CVD). But there appears to be no correlation between long-term, habitual use of coffee with cardiovascular disease or chronic high blood pressure. (5, 6) Low intakes may even be more likely to increase blood pressure with 1–3 cups demonstrating an effect on BP and 3–5 cups showing no long-term effect. (7) Likewise, low intakes have been demonstrated to increase CVD risk slightly (less than three cups per day) with 3–5 cups per day associated with reduced CVD.(8)

Coffee is likely to be beneficial for liver disease

In chronic liver disease, patients who consume coffee have a decreased risk of progression to cirrhosis, a lowered mortality rate, and in chronic hepatitis C patient coffee was associated with improved responses to antiviral therapy. Moreover, coffee consumption is inversely related to the severity of steatohepatitis (fatty liver) in those with pre-existing non-alcoholic fatty liver disease (NAFLD). It is therefore recommended that those with liver disease should be encouraged to drink coffee daily. (9) Gallstone risk is also reduced with higher coffee intakes, with the highest consumption (around six cups or more) associated with the lowest risk. (10)

Women may have an increased risk of bone fracture with higher coffee intakes.

Fracture risk rises in a dose-dependent manner in women but not with men. There is little difference in fracture risk around two coffees per day. (11)

Coffee — a healthy mood-enhancer.

Coffee may also offer some mild protective effect against cognitive decline and dementia, (17) and depression. (18)

What does it all mean?!

A systematic review of seventeen studies including over one million participants and 131,212 death events was conducted by Yimin Zhao and colleagues in May 2015. The review and meta-analysis determined a ‘U-shaped dose-response relationship’ between coffee intake and all-cause mortality. Mortality was reduced at all levels of coffee intake with the greatest effects seen at 3–5 cups. (19)

Based on the evidence, coffee is safe (for most people) and offers significant benefits to health.

The reason for the benefits is likely to be multifactorial and include the effects of caffeine itself and the range of antioxidant chemicals found in coffee.


If you’re overly stressed out, not sleeping well, or you experience negative effects from caffeine; either reduce your dose, switch to decaf or tea (which still offer most of the benefits) or get rid of the coffee altogether.



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