An article reviewing the health benefits and risks of coffee by Melinda Beck in yesterday's Wall Street Journal includes a number of studies that have yielded conflicting results on the effects of coffee. Coffee consumption of varying levels has been correlated with significant differences in the likelihood of being diagnosed with diseases such as diabetes, heart disease, osteoporosis, Alzheimer's and cancers of various kinds, as well as other health conditions such as cholesterol level, hypertension and pregnancy. In some cases, coffee consumption is associated with increased health benefits, in others, it is associated with increased health risks.
The well-balanced article enumerates a number of confounding factors in assessing the health impacts of a cup of coffee: the general challenges of self-reported data, the range of cup sizes (6 to 32 ounces), differences in caffeine levels (75 to 300 milligrams), and the variety of "extras" such as sugar, flavored syrup and whipped cream. It also notes a number of potential hidden factors such as employment, access to health care, exercise and nutrition (several of which have interdependencies). However, having recently written about conversation and community at Starbucks and other coffeehouses, I think that an important hidden health factor omitted from the article is the community context in which coffee is sometimes consumed.
Coffeehouses and other third places have traditionally provided physical spaces where "unrelated people relate". While people are likely to consume coffee in such places, they may also be more likely to engage in conversations with a more diverse array of people with whom they share weak social ties. Although I didn't highlight health effects in my review of Consequential Strangers, the book references a number of studies that demonstrate the health benefits of the diverse social relationships that can be created and maintained in such community-oriented places, such as fewer colds, less depression and anxiety, longer lives, better mental and physical health, and greater likelihood of surviving heart attacks and cancer.
I'm reminded of a 2000 survey by the National Institutes of Health reviewing studies on the health risks and benefits of alcohol consumption, which also included some conflicting results. Aside from people with pre-existing health conditions that are negatively impacted by alcohol, moderate consumption habits - 1 to 2 drinks (with an equivalent of 15 grams of pure alcohol) per day - were more strongly correlated with better health outcomes than either heavy consumption or abstention.
The studies investigating the health effects of alcohol consumption are impacted by some of the same confounding factors as those investigating the health effects of coffee consumption, e.g., reliance on self-reported data and an incomplete accounting of potential hidden factors. Given that pubs, taverns and neighborhood bars are included in the array of prototypical third places - where the health benefits of diverse social relationships would also apply - I suspect that the context of alcohol consumption represents an important, and largely hidden, factor in its health effects.
It would be interesting to conduct studies that would explicitly take into account the community aspects of coffee and/or alcohol consumption, and the resulting variation in health effects. For example, are "grab and go" coffee drinkers more or less likely to enjoy the health benefits associated with coffee than "stay and sip" drinkers? Are pub regulars - with the Cheers cast as extreme exemplars - more or less likely to enjoy the health benefits associated with alcohol than people drinking at home alone? I don't imagine that many people have started - or will start - drinking coffee or alcohol primarily for the reported health benefits, but with the growing health consciousness in American society, demonstrating the health benefits of frequenting third places could affect where people drink coffee and/or alcohol.