Spilling the Beans on Coffee's Health Benefits

                                                                                                     Matthew Johnson, M.D. 

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​Right now, there’s a good chance you have a cup of coffee in your hand or within an arm’s reach. Whether you use it to transform from a zombie to a functioning human being in the morning, to provide an afternoon pick-me-up, or to give you an energy boost before you hit the gym, many of us love coffee and drink it regularly. But is coffee good for you?

Coffee lovers probably don’t think about its health benefits or risks when they grab their daily cup, yet this beverage has been the subject of a long history of debate. In fact, from 1991 until 2016, coffee was labeled as a possible carcinogen by the World Health Organization. Today, many still consider coffee to be a minor health vice that people enjoy because life’s too short not to live a little. After all, coffee contains caffeine and a slew of hard-to-pronounce compounds that sound unhealthy (chlorogenic acid, quinides, and kahweol to name a few); however, others tout the health benefits of coffee and point to its potential antioxidant and anti-inflammatory properties. To assess coffee’s impact on our health, we can look at its relationship to the two leading causes of death and sickness in the US: cancer and cardiovascular disease.
 
First, let’s look at the link between coffee and cancer. Two large academic studies, both published in 2017, provide insight into this relationship. The first found that coffee consumption was related to a lower risk of death from several cancers, including head and neck, colorectal, liver, and female breast cancers, but found a higher risk of death from esophageal cancer in coffee drinkers. The second study combined and re-examined evidence from many smaller studies to report that high coffee consumption (4+ cups per day), compared to low or no coffee consumption (0-4 cups per day), was associated with an overall 18% decreased risk of cancer. Additionally, high coffee consumers had lower risks of numerous individual cancers and no convincingly increased risk of any individual cancer, including esophageal cancer. Together, these studies suggest that coffee consumption is associated with a lower risk of developing cancer. 
 
Next, we can examine the relationship between coffee and cardiovascular disease, the #1 cause of death both in the US and globally. Coffee folklore suggests that coffee and caffeine cause elevated blood pressure, which then leads to heart disease; however, that’s not actually the case. Some evidence suggests no link between coffee and heart disease, while several other studies report that coffee consumption is actually linked to a decreased risk of cardiovascular disease. For example, a collection of studies, including over 1 million individuals, found that individuals with moderate coffee consumption (3-5 cups per day) had a lower risk of cardiovascular disease compared to people who do not consume coffee. Additionally, even people with the highest coffee consumption (5 cups per day) did not have an increased risk of cardiovascular disease.
 
Bringing all the evidence together, it appears that coffee drinking is linked to lower cancer occurrence, a reduction in cardiovascular disease, and even lower mortality from any cause. However, there are always caveats. First, these findings are relevant to the average adult, not pregnant women, kids, or people with specific health conditions who should decrease or eliminate coffee or caffeine intake. Second, as good as the research on this topic is, significant limitations remain because coffee consumption is linked to other behaviors, socioeconomic factors, dietary practices, etc. Therefore, it’s unclear if coffee is causing health benefits, or if coffee consumption is associated with other health-promoting practices or behaviors.
 
So, to answer the question, “Is coffee good for you?” the adage “everything in moderation” likely applies here. It’s safe to say the evidence supports that moderate (~4 cups per day) coffee consumption does not have adverse health effects and may even have multiple health benefits. This means that tomorrow morning or this afternoon, when you’re sipping your coffee, you can enjoy it a little more knowing that it’s both bringing you joy and possibly even supporting your health.

Author
Matthew is a resident physician in internal medicine at Brigham and Women’s Hospital in Boston, Massachusetts. He graduated from Harvard Medical School, where he developed a passion for clinical care and medical education. His career interests include cardiology, medical education, clinical research, and healthcare leadership. In his free time, he enjoys hiking, rock climbing, and reading.