Is Coffee Unhealthy?

Not if it keeps good company

One of the more common statements I hear taking patient histories when patient comment on what measures they had taken already to try to resolve their health issues is “I did give up coffee”.  This statement implies a belief that coffee has negative health effects.  The origins of that concept go back to the 1960s and 1970s. 

During that time regular coffee drinkers often were not in the best health so coffee must be unhealthy.  Realistically that association was more likely related to “who coffee hung out with”, cream and sugar, donuts and a cigarette.  My father came back from WW II a smoker.  Their 4 daily K-rations actually contained 3 cigarettes each or 12 total per day.(1)

But with this collection of factors in the coffee break, the sugar, donut/pastry and cigarettes were the likely unhealthy contributors, not the coffee.  Fast forward to 2000 and after, well done studies that isolate out these other variables actually have found that the coffee likely somewhat minimized the damage done with this multifactor coffee break.

More recent studies have found that the regular, moderate consumption of just coffee lowered the risk of the common metabolic diseases such as diabetes and heart disease.(2)  Moderate coffee consumers actually have a 25-30% lower risk of type two diabetes compared to non-consumers.  New study has confirmed that it is associated with important lower risks of cardiometabolic multimorbidity.(3)  This term refers to a cluster of diseases that often appear in the same patient including heart disease, stroke, diabetes, fatty liver disease and others.

This new study looks at the coffee and tea consumption in over 188,000 subjects comparing that to new onset of these diseases.  Specifically, regarding coffee, those consuming 3 cups per day had the lowest rates of these diseases.  Those consuming little to no coffee had higher rates as did those consuming very high amounts. 

Those consuming 3 cups per day had a hazard ratio of 0.52 which is a reduced risk of 38%.  Tea showed a similar relationship.  The effect is related to the presence of phenols in both coffee and tea, phytochemicals which have antioxidant and anti-inflammatory properties.  All of the studied cardiometabolic diseases are driven by oxidative stress and inflammation.

This early observation that the frequent “coffee breakers” were unhealthy appears to be the result of an error called confounding variables.  This is the observation of a bad outcome when multiple behaviors are involved and arbitrarily assigned to the wrong one. 

The moral of this story is enjoy a good cup of coffee, even with a little almond milk but don’t add the pastry, sugary syrups or cigarettes.

  1. tobacco.stanford.edu/cigarettes/war-aviation/world-war-ii/
  2. Barrea et al.  COFFEE CONSUMPTION, HEALTH BENEFITS AND SIDE EFFECTS: A NARRATIVE REVIEW AND UPDATE FOR DIETITIANS AND NUTRITIONISTS. Critical Reviews in Food Science and Nutrition, 2021;63(9):1238–126.
  3. Lu et al.  HABITUAL COFFEE, TEA, AND CAFFEINE CONSUMPTION, CIRCULATING METABOLITES, AND THE RISK OF CARDIOMETABOLIC MULTIMORBIDITY.  The Journal of Clinical Endocrinology & Metabolism, 2024;dgae552.